None Computing title Tri-Lab Operating System Stack (TOSS) 5 Security Technical Implementation Guide version 1 releaseinfo Release: 1 Vuln_Num V-282352 Rule_ID SV-282352r1200036_rule Severity medium Rule_Title TOSS 5 must automatically expire temporary accounts within 72 hours. Vuln_Discuss Temporary accounts are privileged or nonprivileged accounts that are established during pressing circumstances, such as new software or hardware configuration or an incident response, where the need for prompt account activation requires bypassing normal account authorization procedures. If any inactive temporary accounts are left enabled on the system and are not either manually removed or automatically expired within 72 hours, the security posture of the system will be degraded and exposed to exploitation by unauthorized users or insider threat actors. Temporary accounts are different from emergency accounts. Emergency accounts, also known as "last resort" or "break glass" accounts, are local login accounts enabled on the system for emergency use by authorized system administrators to manage a system when standard login methods are failing or not available. Emergency accounts are not subject to manual removal or scheduled expiration requirements. The automatic expiration of temporary accounts may be extended as needed by the circumstances but it must not be extended indefinitely. A documented permanent account should be established for privileged users who need long-term maintenance accounts. Satisfies: SRG-OS-000002-GPOS-00002, SRG-OS-000123-GPOS-00064 Check_Content Verify temporary accounts have been provisioned with an expiration date of 72 hours. For every existing temporary account, run the following command to obtain its account expiration information: $ sudo chage -l <temporary_account_name> | grep -i "account expires" Verify each of these accounts has an expiration date set within 72 hours. If any temporary accounts have no expiration date or do not expire within 72 hours, this is a finding. Fix_Text Configure the operating system to expire temporary accounts after 72 hours using the following command: $ sudo chage -E $(date -d +3days +%Y-%m-%d) <temporary_account_name> Not_Reviewed Vuln_Num V-282353 Rule_ID SV-282353r1200039_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/sudoers. Vuln_Discuss The actions taken by system administrators must be audited to keep a record of what was executed on the system, as well as for accountability purposes. Editing the sudoers file may be sign of an attacker trying to establish persistent methods to a system, auditing the editing of the sudoers files mitigates this risk. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers" using the following command: $ sudo auditctl -l | grep /etc/sudoers -w /etc/sudoers -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/sudoers -p wa -k identity Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282354 Rule_ID SV-282354r1201500_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/sudoers.d/ directory. Vuln_Discuss The actions taken by system administrators (SAs) must be audited to keep a record of what was executed on the system, as well as for accountability purposes. Editing the sudoers file may be a sign of an attacker trying to establish persistent methods to a system, auditing the editing of the sudoers files mitigates this risk. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221, SRG-OS-000274-GPOS-00104 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers.d/" using the following command: $ sudo auditctl -l | grep /etc/sudoers.d -w /etc/sudoers.d/ -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/sudoers.d/". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/sudoers.d/ -p wa -k identity Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282355 Rule_ID SV-282355r1200045_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/group. Vuln_Discuss In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications must be investigated for legitimacy. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/group" using the following command: $ sudo auditctl -l | egrep '(/etc/group)' -w /etc/group -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/group". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/group -p wa -k identity Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282356 Rule_ID SV-282356r1200048_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/gshadow. Vuln_Discuss In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow" using the following command: $ sudo auditctl -l | egrep '(/etc/gshadow)' -w /etc/gshadow -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/gshadow -p wa -k identity Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282357 Rule_ID SV-282357r1200051_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/opasswd. Vuln_Discuss In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/security/opasswd" using the following command: $ sudo auditctl -l | egrep '(/etc/security/opasswd)' -w /etc/security/opasswd -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/security/opasswd". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/security/opasswd -p wa -k identity Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282358 Rule_ID SV-282358r1200054_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/passwd. Vuln_Discuss In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd" using the following command: $ sudo auditctl -l | egrep '(/etc/passwd)' -w /etc/passwd -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/passwd -p wa -k identity Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282359 Rule_ID SV-282359r1200057_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /etc/shadow. Vuln_Discuss In addition to auditing new user and group accounts, these watches will alert the system administrator(s) to any modifications. Any unexpected users, groups, or modifications should be investigated for legitimacy. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000239-GPOS-00089, SRG-OS-000240-GPOS-00090, SRG-OS-000241-GPOS-00091, SRG-OS-000303-GPOS-00120, SRG-OS-000304-GPOS-00121, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000466-GPOS-00210, SRG-OS-000470-GPOS-00214, SRG-OS-000471-GPOS-00215, SRG-OS-000476-GPOS-00221 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/passwd using the following command: $ sudo auditctl -l | egrep '(/etc/shadow)' -w /etc/shadow -p wa -k identity If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/etc/shadow". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /etc/shadow -p wa -k identity Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282360 Rule_ID SV-282360r1200060_rule Severity medium Rule_Title TOSS 5 must automatically lock an account when three unsuccessful login attempts occur. Vuln_Discuss By limiting the number of failed login attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-force attacks, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128 Check_Content Verify TOSS 5 is configured to lock an account after three unsuccessful login attempts using the command: $ grep 'deny =' /etc/security/faillock.conf deny = 3 If the "deny" option is not set to "3" or less (but not "0"), is missing or commented out, this is a finding. Fix_Text Configure TOSS 5 to lock an account when three unsuccessful login attempts occur. Add or modify the "/etc/security/faillock.conf" file to match the following line: deny = 3 Not_Reviewed Vuln_Num V-282361 Rule_ID SV-282361r1200063_rule Severity medium Rule_Title TOSS 5 must automatically lock an account when three unsuccessful login attempts occur during a 15-minute time period. Vuln_Discuss By limiting the number of failed login attempts, the risk of unauthorized system access via user password guessing, otherwise known as brute-forcing, is reduced. Limits are imposed by locking the account. Satisfies: SRG-OS-000021-GPOS-00005, SRG-OS-000329-GPOS-00128 Check_Content Note: If the system administrator (SA) demonstrates the use of an approved centralized account management method that locks an account after three unsuccessful login attempts within a period of 15 minutes, this requirement is not applicable. Verify TOSS 5 locks an account after three unsuccessful login attempts within a period of 15 minutes using the following command: $ grep fail_interval /etc/security/faillock.conf fail_interval = 900 If the "fail_interval" option is not set to "900" or less (but not "0"), the line is commented out, or the line is missing, this is a finding. Fix_Text Configure TOSS 5 to lock out the "root" account after a number of incorrect login attempts within 15 minutes. Enable "pam_faillock.so" using the following command: $ authselect enable-feature with-faillock Edit the "/etc/security/faillock.conf" file as follows: fail_interval = 900 Not_Reviewed Vuln_Num V-282362 Rule_ID SV-282362r1200066_rule Severity medium Rule_Title TOSS 5 must ensure account lockouts persist. Vuln_Discuss Lockouts persisting across reboots ensure that the account is only unlocked by an administrator. If the lockouts did not persist across reboots, an attacker could simply reboot the system to continue brute-force attacks against the accounts on the system. Check_Content Verify the "/etc/security/faillock.conf" file is configured use a nondefault faillock directory to ensure contents persist after reboot using the following command: $ grep 'dir =' /etc/security/faillock.conf dir = /var/log/faillock If the "dir" option is not set to a nondefault documented tally log directory, is missing or commented out, this is a finding. Fix_Text Configure TOSS 5 to maintain the contents of the faillock directory after a reboot. Add or modify the "/etc/security/faillock.conf" file to match the following line: dir = /var/log/faillock Not_Reviewed Vuln_Num V-282363 Rule_ID SV-282363r1200069_rule Severity medium Rule_Title TOSS 5 must log username information when unsuccessful login attempts occur. Vuln_Discuss Without auditing these events, it may be harder or impossible to identify what an attacker did after an attack. Check_Content Verify the "/etc/security/faillock.conf" file is configured to log username information when unsuccessful login attempts occur using the following command: $ grep audit /etc/security/faillock.conf audit If the "audit" option is not set, is missing, or is commented out, this is a finding. Fix_Text Configure TOSS 5 to log username information when unsuccessful login attempts occur. Add or modify the "/etc/security/faillock.conf" file to match the following line: audit Not_Reviewed Vuln_Num V-282364 Rule_ID SV-282364r1200072_rule Severity medium Rule_Title TOSS 5 must configure the use of the pam_faillock.so module in the /etc/pam.d/system-auth file. Vuln_Discuss If the "pam_faillock.so" module is not loaded, the system will not correctly lockout accounts to prevent password guessing attacks. Check_Content Verify the "pam_faillock.so" module is present in the "/etc/pam.d/system-auth" file: $ grep pam_faillock.so /etc/pam.d/system-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the "pam_faillock.so" module is not present in the "/etc/pam.d/system-auth" file with the "preauth" line listed before "pam_unix.so", this is a finding. Fix_Text Configure TOSS 5 to include the use of the "pam_faillock.so" module in the /etc/pam.d/system-auth file. Add/modify the appropriate sections of the "/etc/pam.d/system-auth" file to match the following lines: Note: The "preauth" line must be listed before "pam_unix.so". auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so Not_Reviewed Vuln_Num V-282365 Rule_ID SV-282365r1200075_rule Severity medium Rule_Title TOSS 5 must configure the use of the pam_faillock.so module in the /etc/pam.d/password-auth file. Vuln_Discuss If the "pam_faillock.so" module is not loaded, the system will not correctly lockout accounts to prevent password guessing attacks. Check_Content Verify the "pam_faillock.so" module is present in the "/etc/pam.d/password-auth" file: $ grep pam_faillock.so /etc/pam.d/password-auth auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so If the "pam_faillock.so" module is not present in the "/etc/pam.d/password-auth" file with the "preauth" line listed before pam_unix.so, this is a finding. Fix_Text Configure TOSS 5 to include the use of the "pam_faillock.so" module in the "/etc/pam.d/password-auth" file. Add/modify the appropriate sections of the "/etc/pam.d/password-auth" file to match the following lines: Note: The "preauth" line must be listed before pam_unix.so. auth required pam_faillock.so preauth auth required pam_faillock.so authfail account required pam_faillock.so Not_Reviewed Vuln_Num V-282366 Rule_ID SV-282366r1200078_rule Severity medium Rule_Title TOSS 5 must display the Standard Mandatory DOD or other applicable U.S. Government Notice and Consent Banner before granting local or remote access to the system via a command line user login. Vuln_Discuss Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. System use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088 Check_Content For nodes of the cluster that are only privately (within the cluster) accessible, this requirement is not applicable. Verify TOSS 5 displays the Standard Mandatory DOD or other applicable U.S. Government Notice and Consent Banner before granting access to the operating system via a command line user login. Check that a banner is displayed at the command line login screen using the following command: $ sudo cat /etc/issue If the banner is set correctly, it will return the following text: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests--not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." If the banner text does not match the Standard Mandatory DOD or other applicable U.S. Government Notice and Consent Banner exactly, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to display the Standard Mandatory DOD or other applicable U.S. Government Notice and Consent Banner before granting access to the system via command line login. Edit the "/etc/issue" file to replace the default text with the Standard Mandatory DOD or other applicable U.S. Government Notice and Consent Banner. The DOD-required text is: "You are accessing a U.S. Government (USG) Information System (IS) that is provided for USG-authorized use only. By using this IS (which includes any device attached to this IS), you consent to the following conditions: -The USG routinely intercepts and monitors communications on this IS for purposes including, but not limited to, penetration testing, COMSEC monitoring, network operations and defense, personnel misconduct (PM), law enforcement (LE), and counterintelligence (CI) investigations. -At any time, the USG may inspect and seize data stored on this IS. -Communications using, or data stored on, this IS are not private, are subject to routine monitoring, interception, and search, and may be disclosed or used for any USG-authorized purpose. -This IS includes security measures (e.g., authentication and access controls) to protect USG interests -- not for your personal benefit or privacy. -Notwithstanding the above, using this IS does not constitute consent to PM, LE or CI investigative searching or monitoring of the content of privileged communications, or work product, related to personal representation or services by attorneys, psychotherapists, or clergy, and their assistants. Such communications and work product are private and confidential. See User Agreement for details." Not_Reviewed Vuln_Num V-282367 Rule_ID SV-282367r1201610_rule Severity medium Rule_Title TOSS 5 must display the Standard Mandatory DOD or other applicable U.S. Government agency Notice and Consent Banner before granting local or remote access to the system via a SSH login. Vuln_Discuss The warning message reinforces policy awareness during the login process and facilitates possible legal action against attackers. Alternatively, systems whose ownership should not be obvious should ensure usage of a banner that does not provide easy attribution. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088 Check_Content Verify any SSH connection to the operating system displays the Standard Mandatory DOD or other applicable U.S. Government agency Notice and Consent Banner before granting access to the system. For nodes of the cluster that are only privately (within the cluster) accessible, this requirement is not applicable. Check for the location of the banner file being used using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*banner' banner /etc/issue This command will return the banner keyword and the name of the file that contains the SSH banner (in this case "/etc/issue"). If the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to display the Standard Mandatory DOD or other applicable U.S. Government agency Notice and Consent Banner before granting access to the system via SSH. Edit the "/etc/ssh/sshd_config" file to uncomment the banner keyword and configure it to point to a file that contains the login banner (this file may be named differently or be in a different location if using a version of SSH that is provided by a third-party vendor). An example configuration line is: Banner /etc/issue Not_Reviewed Vuln_Num V-282368 Rule_ID SV-282368r1200084_rule Severity medium Rule_Title TOSS 5 must display the Standard Mandatory DOD or other applicable U.S. Government agency Notice and Consent Banner before granting local or remote access to the system via a graphical user login. Vuln_Discuss Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. For U.S. Government systems, system use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088 Check_Content Verify TOSS 5 displays a banner before granting access to the operating system via a graphical user login. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine if the operating system displays a banner at the login screen using the following command: $ sudo grep banner-message-enable /etc/dconf/db/local.d/* banner-message-enable=true If "banner-message-enable" is set to "false", is commented out, or is missing, this is a finding. Fix_Text Configure TOSS 5 to display the Standard Mandatory DOD or other applicable U.S. Government agency Notice and Consent Banner before granting access to the system via a graphical user login. Create a database to contain the systemwide graphical user login settings (if it does not already exist) using the following command: $ sudo touch /etc/dconf/db/local.d/01-banner-message Add the following lines to the [org/gnome/login-screen] section of the "/etc/dconf/db/local.d/01-banner-message": [org/gnome/login-screen] banner-message-enable=true Run the following command to update the database: $ sudo dconf update Not_Reviewed Vuln_Num V-282369 Rule_ID SV-282369r1200087_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the banner-message-enable setting for the graphical user interface. Vuln_Discuss Display of a standardized and approved use notification before granting access to the operating system ensures privacy and security notification verbiage used is consistent with applicable federal laws, Executive Orders, directives, policies, regulations, standards, and guidance. For U.S. Government systems, system use notifications are required only for access via login interfaces with human users and are not required when such human interfaces do not exist. Satisfies: SRG-OS-000023-GPOS-00006, SRG-OS-000228-GPOS-00088 Check_Content Verify TOSS 5 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using by running the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Verify the graphical settings are locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep banner-message-enable /etc/dconf/db/local.d/* /org/gnome/login-screen/banner-message-enable If the output is not "/org/gnome/login-screen/banner-message-enable", the line is commented out, or the line is missing, this is a finding. Fix_Text Configure TOSS 5 to prevent a user from overriding the banner setting for graphical user interfaces. Create a database to contain the systemwide graphical user login settings (if it does not already exist) using the following command: $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: banner-message-enable Update the database with the following command: $ sudo dconf update Not_Reviewed Vuln_Num V-282371 Rule_ID SV-282371r1200093_rule Severity low Rule_Title TOSS 5 must limit the number of concurrent sessions to 256 for all accounts and/or account types. Vuln_Discuss Operating system management includes the ability to control the number of users and user sessions that use an operating system. Limiting the number of allowed users and sessions per user is helpful in reducing the risks related to denial-of-service (DoS) attacks. This requirement addresses concurrent sessions for information system accounts and does not address concurrent sessions by single users via multiple system accounts. The maximum number of concurrent sessions should be defined based upon mission needs and the operational environment for each system. Check_Content Verify TOSS limits the number of concurrent sessions to 256 or less for all accounts and/or account types using the following command: $ sudo grep -r -s '^[^#].*maxlogins' /etc/security/limits.conf /etc/security/limits.d/*.conf * hard maxlogins 256 This can be set as a global domain (with the * wildcard) but may be set differently for multiple domains. If the "maxlogins" item is missing, commented out, or the value is set greater than "256" and is not documented with the information system security officer (ISSO) as an operational requirement for all domains that have the "maxlogins" item assigned, this is a finding. Fix_Text Configure TOSS to limit the number of concurrent sessions to 256 or less for all accounts and/or account types. Add the following line to the top of the "/etc/security/limits.conf" or in a ."conf" file defined in "/etc/security/limits.d/": * hard maxlogins 256 Not_Reviewed Vuln_Num V-282372 Rule_ID SV-282372r1201380_rule Severity medium Rule_Title TOSS 5 must directly initiate a session lock for all connection types when the smart card is removed. Vuln_Discuss A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, TOSS 5 must provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000029-GPOS-00010 Check_Content Verify TOSS 5 enables a user's session lock until that user reestablishes access using established identification and authentication procedures using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. $ grep -R removal-action /etc/dconf/db/* /etc/dconf/db/distro.d/20-authselect:removal-action='lock-screen' If the "removal-action='lock-screen'" setting is missing or commented out from the dconf database files, and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure TOSS 5 to enable a user's session lock until that user reestablishes access using established identification and authentication procedures. Select or create an authselect profile and incorporate the "with-smartcard-lock-on-removal" feature with the following example: $ sudo authselect select sssd with-smartcard with-smartcard-lock-on-removal Alternatively, edit the dconf settings in the /etc/dconf/db/* location. Add or update the [org/gnome/settings-daemon/peripherals/smartcard] section of the /etc/dconf/db/local.d/00-security-settings" database file and add or update the following lines: [org/gnome/settings-daemon/peripherals/smartcard] removal-action='lock-screen' Update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282373 Rule_ID SV-282373r1200099_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the disabling of the graphical user smart card removal action. Vuln_Discuss A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Rather than be forced to wait for a period of time to expire before the user session can be locked, TOSS 5 must provide users with the ability to manually invoke a session lock so users can secure their session if it is necessary to temporarily vacate the immediate physical vicinity. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000029-GPOS-00010 Check_Content Verify TOSS 5 disables the user's ability to override the smart card removal action setting. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using by running the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Verify the removal action setting is locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ grep 'removal-action' /etc/dconf/db/local.d/locks/* /org/gnome/settings-daemon/peripherals/smartcard/removal-action If the command does not return at least the example result, this is a finding. Fix_Text Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user override of the smart card removal action: /org/gnome/settings-daemon/peripherals/smartcard/removal-action Update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282374 Rule_ID SV-282374r1201498_rule Severity medium Rule_Title TOSS 5 must enable a user session lock until that user reestablishes access using established identification and authentication procedures for graphical user sessions. Vuln_Discuss A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. The session lock is implemented at the point where session activity can be determined. Regardless of where the session lock is determined and implemented, once invoked, the session lock must remain in place until the user reauthenticates. No other activity aside from reauthentication must unlock the system. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000029-GPOS-00010 Check_Content Verify TOSS 5 enables a user's session lock until that user reestablishes access using established identification and authentication procedures using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. $ gsettings get org.gnome.desktop.screensaver lock-enabled true If the setting is "false", this is a finding. Fix_Text Configure TOSS 5 to enable a user's session lock until that user reestablishes access using established identification and authentication procedures. Create a database to contain the systemwide screensaver settings (if it does not already exist) with the following example: $ sudo vi /etc/dconf/db/local.d/00-screensaver Edit the "[org/gnome/desktop/screensaver]" section of the database file and add or update the following lines: # Set this to true to lock the screen when the screensaver activates lock-enabled=true Update the system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282375 Rule_ID SV-282375r1200105_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the screensaver lock-enabled setting for the graphical user interface. Vuln_Discuss A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, operating systems must be able to identify when a user's session has idled and take action to initiate the session lock. The session lock is implemented at the point where session activity can be determined and/or controlled. Implementing session settings will have little value if a user is able to manipulate these settings from the defaults prescribed in the other requirements of this implementation guide. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000029-GPOS-00010 Check_Content Verify TOSS 5 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—Gnome Shell. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using by running the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i lock-enabled /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-enabled If the command does not return at least the example result, this is a finding. Fix_Text Configure TOSS 5 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the systemwide screensaver settings (if it does not already exist) using the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: /org/gnome/desktop/screensaver/lock-enabled Not_Reviewed Vuln_Num V-282376 Rule_ID SV-282376r1200108_rule Severity medium Rule_Title TOSS 5 must have the tmux package installed. Vuln_Discuss "tmux" is a terminal multiplexer that enables a number of terminals to be created, accessed, and controlled from a single screen. Red Hat endorses "tmux" as the recommended session controlling package. Satisfies: SRG-OS-000028-GPOS-00009, SRG-OS-000030-GPOS-00011 Check_Content Verify TOSS 5 has the "tmux" package installed using the following command: $ sudo dnf list --installed tmux Example output: tmux.x86_64 3.2a-4.el9 If the "tmux" package is not installed, this is a finding. Fix_Text Install the "tmux" package using the following command: $ sudo dnf install tmux Not_Reviewed Vuln_Num V-282377 Rule_ID SV-282377r1200111_rule Severity medium Rule_Title TOSS 5 must automatically lock graphical user sessions after 10 minutes of inactivity. Vuln_Discuss A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and take action to initiate a session lock. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012 Check_Content Verify TOSS 5 initiates a session lock after at most a 10-minute period of inactivity for graphical user interfaces with the following commands: Note: This requirement assumes the use of the TOSS default graphical user interface—Gnome Shell. If the system does not have a graphical user interface installed, this requirement is not applicable. $ sudo gsettings get org.gnome.desktop.session idle-delay uint32 600 If "idle-delay" is set to "0" or a value greater than "600", this is a finding. Fix_Text Configure the operating system to initiate a screensaver after a 10-minute period of inactivity for graphical user interfaces. Create a database to contain the systemwide screensaver settings (if it does not already exist) using the following command: $ sudo touch /etc/dconf/db/local.d/00-screensaver Edit "/etc/dconf/db/local.d/00-screensaver" and add or update the following lines: [org/gnome/desktop/session] # Set the lock time out to 600 seconds before the session is considered idle idle-delay=uint32 600 Update the system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282378 Rule_ID SV-282378r1200114_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the session idle-delay setting for the graphical user interface. Vuln_Discuss A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and act to initiate the session lock. As such, users should not be allowed to change session settings. Satisfies: SRG-OS-000029-GPOS-00010, SRG-OS-000031-GPOS-00012 Check_Content Verify TOSS 5 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using by running the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Verify the graphical settings are locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i idle /etc/dconf/db/local.d/locks/* /org/gnome/desktop/session/idle-delay If the command does not return at least the example result, this is a finding. Fix_Text Configure TOSS 5 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the systemwide screensaver settings (if it does not already exist) using the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: /org/gnome/desktop/session/idle-delay Not_Reviewed Vuln_Num V-282379 Rule_ID SV-282379r1200117_rule Severity medium Rule_Title TOSS 5 must initiate a session lock for graphical user interfaces when the screensaver is activated. Vuln_Discuss A session lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not want to log out because of the temporary nature of the absence. Check_Content Verify TOSS 5 initiates a session lock for graphical user interfaces when the screensaver is activated using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. $ gsettings get org.gnome.desktop.screensaver lock-delay uint32 5 If the "uint32" setting is not "5" or less or is missing, this is a finding. Fix_Text Configure TOSS 5 to initiate a session lock for graphical user interfaces when a screensaver is activated. Create a database to contain the systemwide screensaver settings (if it does not already exist) using the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/00-screensaver [org/gnome/desktop/screensaver] lock-delay=uint32 5 The "uint32" must be included along with the integer key values as shown. Update the system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282380 Rule_ID SV-282380r1200120_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the session lock-delay setting for the graphical user interface. Vuln_Discuss A session time-out lock is a temporary action taken when a user stops work and moves away from the immediate physical vicinity of the information system but does not log out because of the temporary nature of the absence. Rather than relying on the user to manually lock their operating system session prior to vacating the vicinity, the GNOME desktop can be configured to identify when a user's session has idled and take action to initiate the session lock. As such, users should not be allowed to change session settings. Check_Content Verify TOSS 5 prevents a user from overriding settings for graphical user interfaces. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using by running the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ sudo grep -i lock-delay /etc/dconf/db/local.d/locks/* /org/gnome/desktop/screensaver/lock-delay If the command does not return at least the example result, this is a finding. Fix_Text Configure TOSS 5 to prevent a user from overriding settings for graphical user interfaces. Create a database to contain the systemwide screensaver settings (if it does not already exist) using the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/locks/session Add the following setting to prevent nonprivileged users from modifying it: /org/gnome/desktop/screensaver/lock-delay Not_Reviewed Vuln_Num V-282381 Rule_ID SV-282381r1200123_rule Severity medium Rule_Title TOSS 5 must automatically exit interactive command shell user sessions after 15 minutes of inactivity. Vuln_Discuss Terminating an idle interactive command shell user session within a short time period reduces the window of opportunity for unauthorized personnel to take control of it when left unattended in a virtual terminal or physical console. Satisfies: SRG-OS-000030-GPOS-00011, SRG-OS-000163-GPOS-00072, SRG-OS-000279-GPOS-00109 Check_Content Verify TOSS 5 is configured to exit interactive command shell user sessions after 15 minutes of inactivity or less using the following command: $ sudo grep -i tmout /etc/profile /etc/profile.d/*.sh /etc/profile.d/tmout.sh:declare -xr TMOUT=900 If "TMOUT" is not set to "900" or less in a script located in the "/etc/'profile.d/" directory, is missing or is commented out, this is a finding. Fix_Text Configure TOSS 5 to exit interactive command shell user sessions after 15 minutes of inactivity. Add or edit the following line in "/etc/profile.d/tmout.sh": #!/bin/bash declare -xr TMOUT=900 Not_Reviewed Vuln_Num V-282382 Rule_ID SV-282382r1200126_rule Severity medium Rule_Title TOSS 5 must conceal via the session lock information previously visible on the display with a publicly viewable image. Vuln_Discuss Setting the screensaver mode to blank-only conceals the contents of the display from passersby. Check_Content To ensure the screensaver is configured to be blank, run the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. $ gsettings get org.gnome.desktop.screensaver picture-uri If properly configured, the output should be "''". To ensure that users cannot set the screensaver background, run the following: $ grep picture-uri /etc/dconf/db/local.d/locks/* If properly configured, the output should be "/org/gnome/desktop/screensaver/picture-uri". If it is not set or configured properly, this is a finding. Fix_Text Edit the "dconf" settings in the /etc/dconf/db/* location. First, add or update the [org/gnome/desktop/screensaver] section of the "/etc/dconf/db/local.d/00-security-settings" database file and add or update the following lines: [org/gnome/desktop/screensaver] picture-uri='' Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user modification: /org/gnome/desktop/screensaver/picture-uri Update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282383 Rule_ID SV-282383r1200129_rule Severity medium Rule_Title TOSS 5 must log SSH connection attempts and failures to the server. Vuln_Discuss SSH provides several logging levels with varying amounts of verbosity. "DEBUG" is specifically not recommended, other than strictly for debugging SSH communications, because it provides so much data that it is difficult to identify important security information. "INFO" or "VERBOSE" level are the basic levels that only record SSH user login activity. In many situations, such as Incident Response, it is important to determine when a particular user was active on a system. The logout record can eliminate those users who disconnected, which helps narrow the field. Check_Content Verify TOSS 5 logs SSH connection attempts and failures to the server. Verify what the SSH daemon's "LogLevel" option is set to using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*loglevel' LogLevel VERBOSE If a value of "VERBOSE" is not returned or the line is commented out or missing, this is a finding. Fix_Text Configure TOSS 5 to log connection attempts add or modify the following line in "/etc/ssh/sshd_config": LogLevel VERBOSE Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282384 Rule_ID SV-282384r1200132_rule Severity medium Rule_Title All TOSS 5 remote access methods must be monitored. Vuln_Discuss Logging remote access methods can be used to trace the decrease in the risks associated with remote user access management. It can also be used to spot cyberattacks and ensure ongoing compliance with organizational policies surrounding the use of remote access methods. Check_Content Verify TOSS 5 monitors all remote access methods. Check that remote access methods are being logged using the following command: $ grep -rE '(auth.\*|authpriv.\*|daemon.\*)' /etc/rsyslog.conf /etc/rsyslog.conf:authpriv.* If "auth.*", "authpriv.*" or "daemon.*" are not configured to be logged, this is a finding. Fix_Text Add or update the following lines to the "/etc/rsyslog.conf" file: auth.*;authpriv.*;daemon.* /var/log/secure Restart the "rsyslog" service for the changes to take effect using the following command: $ sudo systemctl restart rsyslog.service Not_Reviewed Vuln_Num V-282385 Rule_ID SV-282385r1200135_rule Severity medium Rule_Title TOSS 5 must force a frequent session key renegotiation for SSH connections to the server. Vuln_Discuss Without protection of the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. Session key regeneration limits the chances of a session key becoming compromised. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188 Check_Content Verify the SSH server is configured to force frequent session key renegotiation using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*rekeylimit' RekeyLimit 1G 1h If "RekeyLimit" does not have a maximum data amount and maximum time defined, is missing, or is commented out, this is a finding. Fix_Text Configure TOSS 5 to force a frequent session key renegotiation for SSH connections to the server by adding or modifying the following line in the "/etc/ssh/sshd_config" file: RekeyLimit 1G 1h Restart the SSH daemon for the settings to take effect. $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282386 Rule_ID SV-282386r1200138_rule Severity high Rule_Title TOSS 5 IP tunnels must use FIPS 140-3-approved cryptographic algorithms. Vuln_Discuss Overriding the system crypto policy makes the behavior of the Libreswan service violate expectations and makes system configuration more fragmented. Check_Content Verify the IPsec service uses the system crypto policy using the following command: Note: If the IPsec service is not installed, this requirement is not applicable. $ sudo grep include /etc/ipsec.conf /etc/ipsec.d/*.conf /etc/ipsec.conf:include /etc/crypto-policies/back-ends/libreswan.config If the ipsec configuration file does not contain "include /etc/crypto-policies/back-ends/libreswan.config", this is a finding. Fix_Text Configure Libreswan to use the system cryptographic policy. Add the following line to "/etc/ipsec.conf": include /etc/crypto-policies/back-ends/libreswan.config Not_Reviewed Vuln_Num V-282387 Rule_ID SV-282387r1200141_rule Severity low Rule_Title TOSS 5 must enable auditing of processes that start prior to the audit daemon. Vuln_Discuss Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000462-GPOS-00206, SRG-OS-000471-GPOS-00215, SRG-OS-000473-GPOS-00218, SRG-OS-000254-GPOS-00095 Check_Content Verify that GRUB 2 is configured to enable auditing of processes that start prior to the audit daemon with the following command: $ sudo grubby --info=ALL | grep audit args="ro crashkernel=auto resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 pti=on If "audit" is not set to "1" or is missing, this is a finding. Fix_Text Enable auditing of processes that start prior to the audit daemon with the following command: $ sudo grubby --update-kernel=ALL --args="audit=1" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="audit=1" Not_Reviewed Vuln_Num V-282388 Rule_ID SV-282388r1201627_rule Severity medium Rule_Title TOSS 5 must audit all uses of the chmod, fchmod, and fchmodat system calls. Vuln_Discuss Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172 Check_Content Verify that TOSS 5 is configured to audit the execution of the "chmod", "fchmod", and "fchmodat" system calls with the following command: $ sudo auditctl -l | grep chmod -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chmod", "fchmod", and "fchmodat" system calls, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "chmod", "fchmod", and "fchmodat" syscalls. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chmod,fchmod,fchmodat -F auid>=1000 -F auid!=unset -k perm_mod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282389 Rule_ID SV-282389r1201629_rule Severity medium Rule_Title TOSS 5 must audit all uses of the chown, fchown, fchownat, and lchown system calls. Vuln_Discuss Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "chown", "fchown", "fchownat", and "lchown" system calls with the following command: $ sudo auditctl -l | grep chown -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chown", "fchown", "fchownat", and "lchown" system calls, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "chown", "fchown", "fchownat", and "lchown"" system calls. Add or update the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S chown,fchown,fchownat,lchown -F auid>=1000 -F auid!=unset -k perm_mod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282390 Rule_ID SV-282390r1201503_rule Severity medium Rule_Title TOSS 5 must audit all uses of the setxattr, fsetxattr, lsetxattr, removexattr, fremovexattr, and lremovexattr system calls. Vuln_Discuss Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls with the following command: $ sudo auditctl -l | grep xattr -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod If both the "b32" and "b64" audit rules are not defined for the "chmod", "fchmod", and "fchmodat" system calls "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls, or any of the lines returned are commented out, this is a finding. Fix_Text Configure TOSS 5 to audit the execution of the "setxattr", "fsetxattr", "lsetxattr", "removexattr", "fremovexattr", and "lremovexattr" system calls by adding or updating the following lines to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b32 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod -a always,exit -F arch=b64 -S setxattr,fsetxattr,lsetxattr,removexattr,fremovexattr,lremovexattr -F auid=0 -k perm_mod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282391 Rule_ID SV-282391r1201505_rule Severity medium Rule_Title TOSS 5 must audit all uses of umount system calls. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "umount" command with the following command: $ sudo auditctl -l | grep umount -a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount If the command does not return an audit rule for "umount" or any of the lines returned are commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "umount" command by adding or updating the following rules in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/umount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282392 Rule_ID SV-282392r1201507_rule Severity medium Rule_Title TOSS 5 must audit all uses of the chacl command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "chacl" command with the following command: $ sudo auditctl -l | grep chacl -a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "chacl" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282393 Rule_ID SV-282393r1201509_rule Severity medium Rule_Title TOSS 5 must audit all uses of the setfacl command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "setfacl" command with the following command: $ sudo auditctl -l | grep setfacl -a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "setfacl" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/setfacl -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282394 Rule_ID SV-282394r1201511_rule Severity medium Rule_Title TOSS 5 must audit all uses of the chcon command. Vuln_Discuss Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "chcon" command with the following command: $ sudo auditctl -l | grep chcon -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "chcon" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282395 Rule_ID SV-282395r1201513_rule Severity medium Rule_Title TOSS 5 must audit all uses of the semanage command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "semanage" command with the following command: $ sudo auditctl -l | grep semanage -a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "semanage" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/semanage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282396 Rule_ID SV-282396r1201515_rule Severity medium Rule_Title TOSS 5 must audit all uses of the setfiles command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "setfiles" command with the following command: $ sudo auditctl -l | grep setfiles -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "setfiles" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/setfiles -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282397 Rule_ID SV-282397r1201517_rule Severity medium Rule_Title TOSS 5 must audit all uses of the setsebool command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "setsebool" command with the following command: $ sudo auditctl -l | grep setsebool -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate an audit event for any successful/unsuccessful use of the "setsebool " command by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F path=/usr/sbin/setsebool -F perm=x -F auid>=1000 -F auid!=unset -F key=privileged Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282398 Rule_ID SV-282398r1201519_rule Severity medium Rule_Title TOSS 5 must audit all uses of the rename, unlink, rmdir, renameat, and unlinkat system calls. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit successful/unsuccessful attempts to use the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls with the following command: $ sudo auditctl -l | grep 'rename\|unlink\|rmdir' -a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete If the command does not return an audit rule for "rename", "unlink", "rmdir", "renameat", and "unlinkat" or any of the lines returned are commented out, this is a finding. Fix_Text Configure TOSS 5 to generate an audit event for any successful/unsuccessful use of the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete -a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282399 Rule_ID SV-282399r1201521_rule Severity medium Rule_Title TOSS 5 must audit all uses of the truncate, ftruncate, creat, open, openat, and open_by_handle_at system calls. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit successful/unsuccessful attempts to use the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls with the following command: $ sudo auditctl -l | grep 'open\|truncate\|creat' -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access If the output does not produce rules containing "-F exit=-EPERM", this is a finding. If the output does not produce rules containing "-F exit=-EACCES", this is a finding. If the command does not return an audit rule for "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" or any of the lines returned are commented out, this is a finding. Fix_Text Configure TOSS 5 to generate an audit event for any successful/unsuccessful use of the "truncate", "ftruncate", "creat", "open", "openat", and "open_by_handle_at" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EPERM -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b32 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access -a always,exit -F arch=b64 -S truncate,ftruncate,creat,open,openat,open_by_handle_at -F exit=-EACCES -F auid>=1000 -F auid!=unset -k perm_access Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282400 Rule_ID SV-282400r1201523_rule Severity medium Rule_Title TOSS 5 must audit all uses of the delete_module system call. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "delete_module" system call with the following command: $ sudo auditctl -l | grep delete_module -a always,exit -F arch=b32 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng If both the "b32" and "b64" audit rules are not defined for the "delete_module" system call, or any of the lines returned are commented out, this is a finding. Fix_Text Configure TOSS 5 to generate an audit event for any successful/unsuccessful use of the "delete_module" system call by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S delete_module -F auid>=1000 -F auid!=unset -k module_chng Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282401 Rule_ID SV-282401r1201525_rule Severity medium Rule_Title TOSS 5 must audit all uses of the init_module and finit_module system calls. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "init_module" and "finit_module" system calls with the following command: $ sudo auditctl -l | grep init_module -a always,exit -F arch=b32 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng If both the "b32" and "b64" audit rules are not defined for the "delete_module" system call, or any of the lines returned are commented out, this is a finding. Fix_Text Configure TOSS 5 to generate an audit event for any successful/unsuccessful use of the "init_module" and "finit_module" system calls by adding or updating the following rules in the "/etc/audit/rules.d/audit.rules" file: -a always,exit -F arch=b32 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng -a always,exit -F arch=b64 -S init_module,finit_module -F auid>=1000 -F auid!=unset -k module_chng Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282402 Rule_ID SV-282402r1201527_rule Severity medium Rule_Title TOSS 5 must audit all uses of the chage command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "chage" command with the following command: $ sudo auditctl -l | grep chage -a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-chage If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "chage" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-chage Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282403 Rule_ID SV-282403r1201529_rule Severity medium Rule_Title TOSS 5 must audit all uses of the chsh command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "chsh" command with the following command: $ sudo auditctl -l | grep chsh -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "chsh" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/chsh -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282404 Rule_ID SV-282404r1201531_rule Severity medium Rule_Title TOSS 5 must audit all uses of the crontab command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "crontab" command with the following command: $ sudo auditctl -l | grep crontab -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -k privileged-crontab If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "crontab" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/crontab -F perm=x -F auid>=1000 -F auid!=unset -k privileged-crontab Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282405 Rule_ID SV-282405r1201533_rule Severity medium Rule_Title TOSS 5 must audit all uses of the gpasswd command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "gpasswd" command with the following command: $ sudo auditctl -l | grep gpasswd -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-gpasswd If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "gpasswd" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/gpasswd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-gpasswd Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282406 Rule_ID SV-282406r1201535_rule Severity medium Rule_Title TOSS 5 must audit all uses of the kmod command. Vuln_Discuss Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "kmod" command with the following command: $ sudo auditctl -l | grep kmod -a always,exit -F path=/usr/bin/kmod -F perm=x -F auid>=1000 -F auid!=unset -k modules If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "kmod" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/kmod -F perm=x -F auid>=1000 -F auid!=unset -k modules Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282407 Rule_ID SV-282407r1201537_rule Severity medium Rule_Title TOSS 5 must audit all uses of the newgrp command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "newgrp" command with the following command: $ sudo auditctl -l | grep newgrp -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "newgrp" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/newgrp -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282408 Rule_ID SV-282408r1201539_rule Severity medium Rule_Title TOSS 5 must audit all uses of the pam_timestamp_check command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "pam_timestamp_check" command with the following command: $ sudo auditctl -l | grep timestamp -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pam_timestamp_check If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "pam_timestamp_check" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/pam_timestamp_check -F perm=x -F auid>=1000 -F auid!=unset -k privileged-pam_timestamp_check Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282409 Rule_ID SV-282409r1201541_rule Severity medium Rule_Title TOSS 5 must audit all uses of the passwd command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/etc/gshadow" with the following command: $ sudo auditctl -l | egrep '(/usr/bin/passwd)' -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "passwd" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/passwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-passwd Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282410 Rule_ID SV-282410r1201543_rule Severity medium Rule_Title TOSS 5 must audit all uses of the postdrop command. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "postdrop" command with the following command: $ sudo auditctl -l | grep postdrop -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "postdrop" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/postdrop -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282411 Rule_ID SV-282411r1201545_rule Severity medium Rule_Title TOSS 5 must audit all uses of the postqueue command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "postqueue" command with the following command: $ sudo auditctl -l | grep postqueue -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "postqueue" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/postqueue -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282412 Rule_ID SV-282412r1201547_rule Severity medium Rule_Title TOSS 5 must audit all uses of the ssh-agent command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "ssh-agent" command with the following command: $ sudo auditctl -l | grep ssh-agent -a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "ssh-agent" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/ssh-agent -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282413 Rule_ID SV-282413r1201549_rule Severity medium Rule_Title TOSS 5 must audit all uses of the ssh-keysign command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "ssh-keysign" command with the following command: $ sudo auditctl -l | grep ssh-keysign -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "ssh-keysign" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/libexec/openssh/ssh-keysign -F perm=x -F auid>=1000 -F auid!=unset -k privileged-ssh Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282414 Rule_ID SV-282414r1201551_rule Severity medium Rule_Title TOSS 5 must audit all uses of the su command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "su" command with the following command: $ sudo auditctl -l | grep /usr/bin/su -a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -k privileged-priv_change If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "su" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/su -F perm=x -F auid>=1000 -F auid!=unset -k privileged-priv_change Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282415 Rule_ID SV-282415r1201553_rule Severity medium Rule_Title TOSS 5 must audit all uses of the sudo command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "sudo" command with the following command: $ sudo auditctl -l | grep /usr/bin/sudo -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "sudo" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/sudo -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282416 Rule_ID SV-282416r1201555_rule Severity medium Rule_Title TOSS 5 must audit all uses of the sudoedit command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "sudoedit" command with the following command: $ sudo auditctl -l | grep /usr/bin/sudoedit -a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "sudoedit" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/sudoedit -F perm=x -F auid>=1000 -F auid!=unset -k priv_cmd Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282417 Rule_ID SV-282417r1201557_rule Severity medium Rule_Title TOSS 5 must audit all uses of the unix_chkpwd command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "unix_chkpwd" command with the following command: $ sudo auditctl -l | grep unix_chkpwd -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "unix_chkpwd" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/unix_chkpwd -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282418 Rule_ID SV-282418r1201559_rule Severity medium Rule_Title TOSS 5 must audit all uses of the unix_update command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "unix_update" command with the following command: $ sudo auditctl -l | grep unix_update -a always,exit -F path=/usr/sbin/unix_update -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "unix_update" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/unix_update -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282419 Rule_ID SV-282419r1201561_rule Severity medium Rule_Title TOSS 5 must audit all uses of the userhelper command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "userhelper" command with the following command: $ sudo auditctl -l | grep userhelper -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "userhelper" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/userhelper -F perm=x -F auid>=1000 -F auid!=unset -k privileged-unix-update Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282420 Rule_ID SV-282420r1201563_rule Severity medium Rule_Title TOSS 5 must audit all uses of the usermod command. Vuln_Discuss Without generating audit record specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "usermod" command with the following command: $ sudo auditctl -l | grep usermod -a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -k privileged-usermod If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "usermod " command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/sbin/usermod -F perm=x -F auid>=1000 -F auid!=unset -k privileged-usermod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282421 Rule_ID SV-282421r1201565_rule Severity medium Rule_Title TOSS 5 must audit all uses of the mount command. Vuln_Discuss Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter). When a user logs on, the auid is set to the uid of the account that is being authenticated. Daemons are not user sessions and have the loginuid set to -1. The auid representation is an unsigned 32-bit integer, which equals 4294967295. The audit system interprets -1, 4294967295, and "unset" in the same way. The system call rules are loaded into a matching engine that intercepts each system call made by all programs on the system. Therefore, it is very important to use system call rules only when absolutely necessary since these affect performance. The more rules, the bigger the performance hit. The performance can be helped, however, by combining system calls into one rule whenever possible. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 is configured to audit the execution of the "mount" command with the following command: $ sudo auditctl -l | grep /usr/bin/mount -a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records upon successful/unsuccessful attempts to use the "mount" command by adding or updating the following rule in "/etc/audit/rules.d/audit.rules": -a always,exit -F path=/usr/bin/mount -F perm=x -F auid>=1000 -F auid!=unset -k privileged-mount Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282422 Rule_ID SV-282422r1201567_rule Severity medium Rule_Title Successful/unsuccessful uses of the umount system call in TOSS 5 must generate an audit record. Vuln_Discuss The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify that TOSS 5 generates an audit record for all uses of the "umount" and system call with the following command: $ sudo grep "umount" /etc/audit/audit.* -a always,exit -F arch=b32 -S umount -F auid>=1000 -F auid!=unset -k privileged-umount If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure the audit system to generate an audit event for any successful/unsuccessful use of the "umount" system call by adding or updating the following rules in "/etc/audit/audit.rules" and adding the following rules to "/etc/audit/rules.d/perm_mod.rules" or updating the existing rules in files in the "/etc/audit/rules.d/" directory: -a always,exit -F arch=b32 -S umount -F auid>=1000 -F auid!=unset -k privileged-umount Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282423 Rule_ID SV-282423r1201569_rule Severity medium Rule_Title Successful/unsuccessful uses of the umount2 system call in TOSS 5 must generate an audit record. Vuln_Discuss The changing of file permissions could indicate that a user is attempting to gain access to information that would otherwise be disallowed. Auditing DAC modifications can facilitate the identification of patterns of abuse among both authorized and unauthorized users. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content To determine if the system is configured to audit calls to the umount2 system call, run the following command: $ sudo grep "umount2" /etc/audit/audit.* If no line is returned, this is a finding. Fix_Text Configure the audit system to generate an audit event for any successful/unsuccessful use of the "umount2" system call by adding or updating the following rules in "/etc/audit/audit.rules" and adding the following rules to "/etc/audit/rules.d/perm_mod.rules" or updating the existing rules in files in the "/etc/audit/rules.d/" directory: -a always,exit -F arch=b32 -S umount2 -F auid>=1000 -F auid!=unset -k perm_mod -a always,exit -F arch=b64 -S umount2 -F auid>=1000 -F auid!=unset -k perm_mod Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282424 Rule_ID SV-282424r1201571_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/lastlog. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Satisfies: SRG-OS-000037-GPOS-00015, SRG-OS-000042-GPOS-00020, SRG-OS-000062-GPOS-00031, SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/lastlog" with the following command: $ sudo auditctl -l | grep /var/log/lastlog -w /var/log/lastlog -p wa -k logins If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/lastlog". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /var/log/lastlog -p wa -k logins Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282425 Rule_ID SV-282425r1201625_rule Severity medium Rule_Title TOSS 5 must label all offloaded audit logs before sending them to the central log server. Vuln_Discuss Enriched logging is needed to determine who, what, and when events occur on a system. Without this, determining root cause of an event will be much more difficult. When audit logs are not labeled before they are sent to a central log server, the audit data will not be able to be analyzed and tied back to the correct system. Check_Content Verify that TOSS 5 Audit Daemon is configured to label all offloaded audit logs, with the following command: $ sudo grep name_format /etc/audit/auditd.conf name_format = hostname If the "name_format" option is not "hostname", "fqd", or "numeric", or the line is commented out, this is a finding. Fix_Text Edit the /etc/audit/auditd.conf file and add or update the "name_format" option: name_format = hostname Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282426 Rule_ID SV-282426r1200258_rule Severity medium Rule_Title TOSS 5 must forward mail from postmaster to the root account using a postfix alias. Vuln_Discuss It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. Check_Content Verify the administrators are notified in the event of an audit processing failure. Verify the "/etc/aliases" file has a defined value for "root". $ sudo grep "postmaster:\s*root$" /etc/aliases If the command does not return a line, or the line is commented out, ask the system administrator to indicate how they and the information systems security officer (ISSO) are notified of an audit process failure. If there is no evidence of the proper personnel being notified of an audit processing failure, this is a finding. Fix_Text Configure a valid email address as an alias for the root account. Append the following line to "/etc/aliases": postmaster: root Run the following command: $ sudo newaliases Not_Reviewed Vuln_Num V-282427 Rule_ID SV-282427r1200261_rule Severity medium Rule_Title TOSS 5 system administrators (SAs) and/or information system security officer (ISSOs) (at a minimum) must be alerted of an audit processing failure event. Vuln_Discuss It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. Satisfies: SRG-OS-000046-GPOS-00022, SRG-OS-000343-GPOS-00134 Check_Content Verify TOSS 5 is configured to notify the SA and/or ISSO (at a minimum) in the event of an audit processing failure using the following command: $ sudo grep action_mail_acct /etc/audit/auditd.conf action_mail_acct = root If the value of the "action_mail_acct" keyword is not set to "root" and/or other accounts for security personnel, the "action_mail_acct" keyword is missing, or the retuned line is commented out, ask the SA to indicate how they and the ISSO are notified of an audit process failure. If there is no evidence of the proper personnel being notified of an audit processing failure, this is a finding. Fix_Text Configure "auditd" service to notify the SA and ISSO in the event of an audit processing failure. Edit the following line in "/etc/audit/auditd.conf" to ensure that administrators are notified via email for those situations: action_mail_acct = root Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282428 Rule_ID SV-282428r1200264_rule Severity medium Rule_Title TOSS 5 must have mail aliases to notify the information system security officer (ISSO) and system administrator (SA) (at a minimum) in the event of an audit processing failure. Vuln_Discuss It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. This requirement applies to each audit data storage repository (i.e., distinct information system component where audit records are stored), the centralized audit storage capacity of organizations (i.e., all audit data storage repositories combined), or both. Check_Content Verify TOSS 5 is configured to notify the appropriate interactive users in the event of an audit processing failure. Find the alias maps in use with the following command: $ postconf alias_maps alias_maps = hash:/etc/aliases Query the Postfix alias maps for an alias for the root user with the following command: $ postmap -q root hash:/etc/aliases isso If an alias is not set, this is a finding. Fix_Text Edit the aliases map file (by default, /etc/aliases) used by Postfix and configure a root alias (using the user ISSO as an example): root: ISSO Update the aliases database with the command: $ sudo newaliases Not_Reviewed Vuln_Num V-282429 Rule_ID SV-282429r1200267_rule Severity medium Rule_Title TOSS 5 must take appropriate action when a critical audit processing failure occurs. Vuln_Discuss It is critical for the appropriate personnel to be aware if a system is at risk of failing to process audit logs as required. Without this notification, the security personnel may be unaware of an impending failure of the audit capability, and system operation may be adversely affected. Audit processing failures include software/hardware errors, failures in the audit capturing mechanisms, and audit storage capacity being reached or exceeded. Check_Content Verify the audit service is configured to panic on a critical error using the following command: $ sudo grep "\-f" /etc/audit/audit.rules -f 2 If the value for "-f" is not "2", and availability is not documented as an overriding concern, this is a finding. Fix_Text Configure TOSS 5 to shut down when auditing failures occur. Add the following line to the bottom of the "/etc/audit/audit.rules" file: -f 2 Not_Reviewed Vuln_Num V-282430 Rule_ID SV-282430r1200270_rule Severity medium Rule_Title TOSS 5 must periodically flush audit records to disk to prevent the loss of audit records. Vuln_Discuss If option "freq" is not set to a value that requires audit records being written to disk after a threshold number is reached, then audit records may be lost. Check_Content Verify the audit system is configured to flush to disk after every 100 records using the following command: $ sudo grep freq /etc/audit/auditd.conf freq = 100 If "freq" isn't set to a value between "1" and "100", the value is missing, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to flush audit to disk by adding or updating the following rule in "/etc/audit/auditd.conf": freq = 100 Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282431 Rule_ID SV-282431r1200273_rule Severity medium Rule_Title TOSS 5 audit logs must be group-owned by root or by a restricted logging group to prevent unauthorized read access. Vuln_Discuss Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084 Check_Content Verify the audit logs are group-owned by "root" or a restricted logging group. First determine if a group other than "root" has been assigned to the audit logs using the following command: $ sudo grep log_group /etc/audit/auditd.conf Determine where the audit logs are stored using the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Using the location of the audit log file, determine if the audit log is group-owned by "root" using the following command: $ sudo stat -c "%G %n" /var/log/audit/audit.log root /var/log/audit/audit.log If the audit log is not group-owned by "root" or the configured alternative logging group, this is a finding. Fix_Text Change the group of the directory of "/var/log/audit" to be owned by a correct group. Identify the group that is configured to own audit log: $ sudo grep -P '^[ ]*log_group[ ]+=.*$' /etc/audit/auditd.conf Change the ownership to that group: $ sudo chgrp ${GROUP} /var/log/audit Not_Reviewed Vuln_Num V-282432 Rule_ID SV-282432r1200276_rule Severity medium Rule_Title TOSS 5 audit log directory must be owned by root to prevent unauthorized read access. Vuln_Discuss Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084 Check_Content Verify the audit logs directory is owned by "root". Determine where the audit logs are stored using the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Using the location of the audit log file, determine if the audit log directory is owned by "root" using the following command: $ sudo ls -ld /var/log/audit drwx------ 2 root root 23 Jun 11 11:56 /var/log/audit If the audit log directory is not owned by "root", this is a finding. Fix_Text Configure the audit log to be protected from unauthorized read access by setting the correct owner as "root" using the following command: $ sudo chown root /var/log/audit Not_Reviewed Vuln_Num V-282433 Rule_ID SV-282433r1200279_rule Severity medium Rule_Title TOSS 5 audit logs file must have mode 0600 or less permissive to prevent unauthorized access to the audit log. Vuln_Discuss Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the TOSS 5 system or platform. Additionally, Personally Identifiable Information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000206-GPOS-00084 Check_Content Verify the audit logs have a mode of "0600". Determine where the audit logs are stored using the following command: $ sudo grep -iw log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Using the location of the audit log file, determine if the audit log files as a mode of "0640" using the following command: $ sudo ls -la /var/log/audit/*.log rw-------. 2 root root 237923 Jun 11 11:56 /var/log/audit/audit.log If the audit logs have a mode more permissive than "0600", this is a finding. Fix_Text Configure the audit logs to have a mode of "0600" using the following command: Replace "[audit_log_file]" to the correct audit log path, by default this location is "/var/log/audit/audit.log". $ sudo chmod 0600 /var/log/audit/[audit_log_file] Check the group that owns the system audit logs: $ sudo grep -m 1 -q ^log_group /etc/audit/auditd.conf If the "log_group" is not defined or it is set to "root", configure the permissions as follows: $ sudo chmod 0640 $log_file $ sudo chmod 0440 $log_file.* Otherwise, configure the permissions as follows: $ sudo chmod 0600 $log_file $ sudo chmod 0400 $log_file.* Not_Reviewed Vuln_Num V-282434 Rule_ID SV-282434r1200282_rule Severity medium Rule_Title TOSS 5 audit system must protect login user identifiers (UIDs) from unauthorized change. Vuln_Discuss If modification of login UIDs is not prevented, they can be changed by nonprivileged users and make auditing complicated or impossible. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029, SRG-OS-000462-GPOS-00206, SRG-OS-000475-GPOS-00220 Check_Content Verify the audit system prevents unauthorized changes to login UIDs using the following command: $ sudo grep -i immutable /etc/audit/audit.rules --loginuid-immutable If the "--loginuid-immutable" option is not returned in the "/etc/audit/audit.rules", or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 auditing to prevent modification of login UIDs once they are set by adding the following line to "/etc/audit/rules.d/audit.rules": --loginuid-immutable Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282435 Rule_ID SV-282435r1200285_rule Severity medium Rule_Title TOSS 5 audit system must protect auditing rules from unauthorized change. Vuln_Discuss Unauthorized disclosure of audit records can reveal system and configuration data to attackers, thus compromising its confidentiality. Audit information includes all information (e.g., audit records, audit settings, audit reports) needed to successfully audit TOSS 5 system activity. In immutable mode, unauthorized users cannot execute changes to the audit system to potentially hide malicious activity and then put the audit rules back. A system reboot would be noticeable, and a system administrator could then investigate the unauthorized changes. Satisfies: SRG-OS-000057-GPOS-00027, SRG-OS-000058-GPOS-00028, SRG-OS-000059-GPOS-00029 Check_Content Verify the audit system prevents unauthorized changes using the following command: $ sudo grep "^\s*[^#]" /etc/audit/audit.rules | tail -1 -e 2 If the audit system is not set to be immutable by adding the "-e 2" option to the end of "/etc/audit/audit.rules", this is a finding. Fix_Text Configure the audit system to set the audit rules to be immutable by adding the following line to end of "/etc/audit/rules.d/audit.rules": -e 2 Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282436 Rule_ID SV-282436r1200288_rule Severity low Rule_Title TOSS 5 must enable Linux audit logging for the USBGuard daemon. Vuln_Discuss Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Audit records can be generated from various components within the information system (e.g., module or policy filter). The list of audited events is the set of events for which audits are to be generated. This set of events is typically a subset of the list of all events for which the system can generate audit records. DOD has defined the list of events for which TOSS 5 will provide an audit record generation capability as the following: 1) Successful and unsuccessful attempts to access, modify, or delete privileges, security objects, security levels, or categories of information (e.g., classification levels); 2) Access actions, such as successful and unsuccessful login attempts, privileged activities or other system-level access, starting and ending time for user access to the system, concurrent logins from different workstations, successful and unsuccessful accesses to objects, all program initiations, and all direct access to the information system; 3) All account creations, modifications, disabling, and terminations; and 4) All kernel module load, unload, and restart actions. Check_Content Verify Linux Audit logging is enabled for the USBGuard daemon using the following command: $ sudo grep AuditBackend /etc/usbguard/usbguard-daemon.conf AuditBackend=LinuxAudit If "AuditBackend" is not set to "LinuxAudit", this is a finding. Fix_Text Configure TOSS 5 USBGuard AuditBackend to use the audit system. Add or edit the following line in "/etc/usbguard/usbguard-daemon.conf": AuditBackend=LinuxAudit Not_Reviewed Vuln_Num V-282437 Rule_ID SV-282437r1200291_rule Severity medium Rule_Title TOSS 5 audit package must be installed. Vuln_Discuss Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Associating event types with detected events in audit logs provides a means of investigating an attack, recognizing resource utilization or capacity thresholds, or identifying an improperly configured TOSS 5 system. Satisfies: SRG-OS-000062-GPOS-00031, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000458-GPOS-00203, SRG-OS-000461-GPOS-00205, SRG-OS-000463-GPOS-00207, SRG-OS-000465-GPOS-00209, SRG-OS-000467-GPOS-00211, SRG-OS-000468-GPOS-00212, SRG-OS-000471-GPOS-00216, SRG-OS-000473-GPOS-00218, SRG-OS-000475-GPOS-00220 Check_Content Verify the TOSS 5 audit service package is installed. Check that the audit service package is installed using the following command: $ sudo dnf list --installed audit Example output: audit-3.0.7-101.el9_0.2.x86_64 If the "audit" package is not installed, this is a finding. Fix_Text Install the audit service package (if the audit service is not already installed) using the following command: $ sudo dnf install audit Not_Reviewed Vuln_Num V-282438 Rule_ID SV-282438r1200294_rule Severity medium Rule_Title TOSS 5 audit service must be enabled. Vuln_Discuss Without establishing what type of events occurred, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Ensuring the "auditd" service is active ensures audit records generated by the kernel are appropriately recorded. Additionally, a properly configured audit subsystem ensures that actions of individual system users can be uniquely traced to those users so they can be held accountable for their actions. Satisfies: SRG-OS-000062-GPOS-00031, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000358-GPOS-00145, SRG-OS-000365-GPOS-00152, SRG-OS-000392-GPOS-00172, SRG-OS-000475-GPOS-00220 Check_Content Verify the audit service is configured to produce audit records using the following command: $ systemctl status auditd.service auditd.service - Security Auditing Service Loaded:loaded (/usr/lib/systemd/system/auditd.service; enabled; vendor preset: enabled) Active: active (running) since Tues 2022-05-24 12:56:56 EST; 4 weeks 0 days ago If the audit service is not "active" and "running", this is a finding. Fix_Text To enable the audit service, run the following command: $ sudo systemctl enable --now auditd Not_Reviewed Vuln_Num V-282439 Rule_ID SV-282439r1200297_rule Severity medium Rule_Title The TOSS 5 audit system must audit local events. Vuln_Discuss Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. If option "local_events" isn't set to "yes", only events from network will be aggregated. Check_Content Verify the TOSS 5 audit system is configured to audit local events using the following command: $ sudo grep local_events /etc/audit/auditd.conf local_events = yes If "local_events" is not set to "yes", if the command does not return a line, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for local events by adding or updating the following line in "/etc/audit/auditd.conf": local_events = yes Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282440 Rule_ID SV-282440r1200300_rule Severity medium Rule_Title TOSS 5 must allow only the information system security manager (ISSM) (or individuals or roles appointed by the ISSM) to select which auditable events are to be audited. Vuln_Discuss Without the capability to restrict the roles and individuals that can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Check_Content Verify the files in directory "/etc/audit/rules.d/" and "/etc/audit/auditd.conf" file have a mode of "0640" or less permissive using the following command: # stat -c "%a %n" /etc/audit/rules.d/*.rules 640 /etc/audit/rules.d/audit.rules If the files in the "/etc/audit/rules.d/" directory or the "/etc/audit/auditd.conf" file have a mode more permissive than "0640", this is a finding. Fix_Text Configure the files in directory "/etc/audit/rules.d/" and the "/etc/audit/auditd.conf" file to have a mode of "0640" with the following commands: $ sudo chmod 0640 /etc/audit/rules.d/audit.rules $ sudo chmod 0640 /etc/audit/rules.d/[customrulesfile].rules $ sudo chmod 0640 /etc/audit/auditd.conf Not_Reviewed Vuln_Num V-282441 Rule_ID SV-282441r1200303_rule Severity medium Rule_Title TOSS 5 /etc/audit/auditd.conf file must have 0640 or less permissive to prevent unauthorized access. Vuln_Discuss Without the capability to restrict the roles and individuals that can select which events are audited, unauthorized personnel may be able to prevent the auditing of critical events. Misconfigured audits may degrade the system's performance by overwhelming the audit log. Misconfigured audits may also make it more difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Check_Content Verify the mode of the "/etc/audit/auditd.conf" file with the command: $ sudo stat -c "%a %n" /etc/audit/auditd.conf 640 /etc/audit/auditd.conf If "/etc/audit/auditd.conf" does not have a mode of "0640", this is a finding. Fix_Text Set the mode of the "/etc/audit/auditd.conf" file to "0640" with the command: $ sudo chmod 0640 /etc/audit/auditd.conf Not_Reviewed Vuln_Num V-282442 Rule_ID SV-282442r1200306_rule Severity medium Rule_Title TOSS 5, for PKI-based authentication, must validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Vuln_Discuss Without path validation, an informed trust decision by the relying party cannot be made when presented with any certificate not already explicitly trusted. A trust anchor is an authoritative entity represented via a public key and associated data. It is used in the context of public key infrastructures, X.509 digital certificates, and DNSSEC. When there is a chain of trust, usually the top entity to be trusted becomes the trust anchor; it can be, for example, a Certification Authority (CA). A certification path starts with the subject certificate and proceeds through a number of intermediate certificates up to a trusted root certificate, typically issued by a trusted CA. This requirement verifies that a certification path to an accepted trust anchor is used for certificate validation and that the path includes status information. Path validation is necessary for a relying party to make an informed trust decision when presented with any certificate not already explicitly trusted. Status information for certification paths includes certificate revocation lists or online certificate status protocol responses. Validating the certificate status information is out of scope for this requirement. Satisfies: SRG-OS-000066-GPOS-00034, SRG-OS-000384-GPOS-00167 Check_Content If PKI-based authentication is used, verify TOSS 5 has valid certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Check that the system has a valid DOD root CA installed using the following command: Note: If the system does not support PKI authentication, this requirement is not applicable. $ sudo openssl x509 -text -in /etc/sssd/pki/sssd_auth_ca_db.pem Certificate: Data: Version: 3 (0x2) Serial Number: 1 (0x1) Signature Algorithm: sha256WithRSAEncryption Issuer: C = US, O = U.S. Government, OU = DOD, OU = PKI, CN = DOD Root CA 3 Validity Not Before: Mar 20 18:46:41 2012 GMT Not After : Dec 30 18:46:41 2029 GMT Subject: C = US, O = U.S. Government, OU = DOD, OU = PKI, CN = DOD Root CA 3 Subject Public Key Info: Public Key Algorithm: rsaEncryption If the root CA file is not a DOD-issued certificate with a valid date and installed in the "/etc/sssd/pki/sssd_auth_ca_db.pem" location, this is a finding. Fix_Text If PKI-based authentication is used, configure TOSS 5 to validate certificates by constructing a certification path (which includes status information) to an accepted trust anchor. Obtain a valid copy of the DOD root CA file from the PKI CA certificate bundle from cyber.mil and copy it into the following file: /etc/sssd/pki/sssd_auth_ca_db.pem Not_Reviewed Vuln_Num V-282443 Rule_ID SV-282443r1200309_rule Severity medium Rule_Title TOSS 5, for public key infrastructure (PKI)-based authentication, must enforce authorized access to the corresponding private key. Vuln_Discuss If the private key is discovered, an attacker can use it to authenticate as an authorized user and gain access to the network infrastructure. The cornerstone of the PKI is the private key used to encrypt or digitally sign information. If the private key is stolen, this will lead to the compromise of the authentication and nonrepudiation gained through PKI because the attacker can use the private key to digitally sign documents and pretend to be the authorized user. Both the holders of a digital certificate and the issuing authority must protect the computers, storage devices, or whatever they use to keep the private keys. Check_Content If the system does not allow PKI authentication, this requirement is not applicable. Verify the operating system, for PKI-based authentication, enforces authorized access to the corresponding private key. Verify the SSH private key files have a passphrase. For each private key stored on the system, use the following command: $ sudo ssh-keygen -y -f /path/to/file If the contents of the key are displayed, and use of un-passphrased Secure Shell (SSH) keys is not documented with the information system security officer, this is a finding. Fix_Text Create a new private and public key pair that uses a passcode using the following command: $ sudo ssh-keygen -n [passphrase] Not_Reviewed Vuln_Num V-282444 Rule_ID SV-282444r1200312_rule Severity medium Rule_Title TOSS 5 must map the authenticated identity to the user or group account for PKI-based authentication. Vuln_Discuss Without mapping the certificate used to authenticate to the user account, the ability to determine the identity of the individual user or group will not be available for forensic analysis. Check_Content Verify the certificate of the user or group is mapped to the corresponding user or group in the "sssd.conf" file using the following command: $ sudo cat /etc/sssd/sssd.conf [certmap/testing.test/rule_name] matchrule =<SAN>.*EDIPI@mil maprule = (userCertificate;binary={cert!bin}) domains = testing.test If the certmap section does not exist, ask the system administrator (SA) to indicate how certificates are mapped to accounts. If there is no evidence of certificate mapping, this is a finding. Fix_Text Configure TOSS 5 to map the authenticated identity to the user or group account by adding or modifying the certmap section of the "/etc/sssd/sssd.conf" file based on the following example: [certmap/testing.test/rule_name] matchrule = .*EDIPI@mil maprule = (userCertificate;binary={cert!bin}) dmains = testing.test Restart the "sssd" service for the changes to take effect. To restart the "sssd" service, run the following command: $ sudo systemctl restart sssd.service Not_Reviewed Vuln_Num V-282445 Rule_ID SV-282445r1200315_rule Severity medium Rule_Title TOSS 5 must ensure the password complexity module in the system-auth file is configured for three retries or less. Vuln_Discuss Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. "pwquality" enforces complex password construction configuration and has the ability to limit brute-force attacks on the system. TOSS 5 uses "pwquality" as a mechanism to enforce password complexity. This is set in both: /etc/pam.d/password-auth /etc/pam.d/system-auth By limiting the number of attempts to meet the pwquality module complexity requirements before returning with an error, the system will audit abnormal attempts at password changes. Check_Content Verify TOSS 5 is configured to limit the "pwquality" retry option to "3". Verify the use of the "pwquality" retry option in the "system-auth file" using the following command: $ cat /etc/pam.d/system-auth | grep pam_pwquality password required pam_pwquality.so retry=3 If the value of "retry" is set to "0" or greater than "3", or is missing, this is a finding. Fix_Text Configure TOSS 5 to limit the "pwquality" retry option to "3". Add the following line to the "/etc/pam.d/system-auth" file (or modify the line to have the required value): password required pam_pwquality.so retry=3 Not_Reviewed Vuln_Num V-282446 Rule_ID SV-282446r1200318_rule Severity high Rule_Title TOSS 5 must ensure the password complexity module is enabled in the password-auth file. Vuln_Discuss Enabling PAM password complexity permits enforcement of strong passwords and consequently makes the system less prone to dictionary attacks. Check_Content Verify TOSS 5 uses "pwquality" to enforce the password complexity rules in the "password-auth" file using the following command: $ cat /etc/pam.d/password-auth | grep pam_pwquality password required pam_pwquality.so If the command does not return a line containing the value "pam_pwquality.so", or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to use "pwquality" to enforce password complexity rules. Add the following line to the "/etc/pam.d/password-auth" file (or modify the line to have the required value): password required pam_pwquality.so Not_Reviewed Vuln_Num V-282447 Rule_ID SV-282447r1200321_rule Severity medium Rule_Title TOSS 5 must enforce password complexity by requiring at least one uppercase character. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised. Requiring a minimum number of uppercase characters makes password guessing attacks more difficult by ensuring a larger search space. Check_Content Verify TOSS 5 enforces password complexity by requiring at least one uppercase character. Check the value for "ucredit" using the following command: $ sudo grep ucredit /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf ucredit = -1 If the value of "ucredit" is a positive number or is commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce password complexity by requiring that at least one uppercase character be used by setting the "ucredit" option. Add the following line to /etc/security/pwquality.conf (or modify the line to have the required value): ucredit = -1 Not_Reviewed Vuln_Num V-282448 Rule_ID SV-282448r1200324_rule Severity medium Rule_Title TOSS 5 must enforce password complexity by requiring that at least one lowercase character be used. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised. Requiring a minimum number of lowercase characters makes password guessing attacks more difficult by ensuring a larger search space. Check_Content Verify TOSS 5 enforces password complexity by requiring at least one lowercase character. Check the value for "lcredit" using the following command: $ sudo grep lcredit /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf /etc/security/pwquality.conf:lcredit = -1 If the value of "lcredit" is a positive number or is commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce password complexity by requiring at least one lowercase character be used by setting the "lcredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): lcredit = -1 Not_Reviewed Vuln_Num V-282449 Rule_ID SV-282449r1200327_rule Severity medium Rule_Title TOSS 5 must enforce password complexity by requiring that at least one numeric character be used. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised. Requiring digits makes password guessing attacks more difficult by ensuring a larger search space. Check_Content Verify TOSS 5 enforces password complexity by requiring at least one numeric character. Check the value for "dcredit" using the following command: $ sudo grep dcredit /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf /etc/security/pwquality.conf:dcredit = -1 If the value of "dcredit" is a positive number or is commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce password complexity by requiring at least one numeric character be used by setting the "dcredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): dcredit = -1 Not_Reviewed Vuln_Num V-282450 Rule_ID SV-282450r1200330_rule Severity medium Rule_Title TOSS 5 must enforce password complexity rules for the root account. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised. Check_Content Verify TOSS 5 enforces password complexity rules for the root account. Check if root user is required to use complex passwords using the following command: $ grep enforce_for_root /etc/security/pwquality.conf /etc/security/pwquality.conf/*.conf /etc/security/pwquality.conf:enforce_for_root If "enforce_for_root" is commented or missing, this is a finding. Fix_Text Configure TOSS 5 to enforce password complexity on the root account. Add or update the following line in "/etc/security/pwquality.conf": enforce_for_root Not_Reviewed Vuln_Num V-282451 Rule_ID SV-282451r1200333_rule Severity medium Rule_Title TOSS 5 must require users to change at least eight characters when changing passwords. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised. Requiring a minimum number of different characters during password changes ensures that newly changed passwords will not resemble previously compromised ones. Note that passwords changed on compromised systems will still be compromised. Check_Content Verify the value of the "difok" option in "/etc/security/pwquality.conf" using the following command: $ sudo grep difok /etc/security/pwquality.conf difok = 8 If the value of "difok" is set to less than "8", or is commented out, this is a finding. Fix_Text Configure TOSS 5 to require the change of at least eight of the total number of characters when passwords are changed by setting the "difok" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): difok = 8 Not_Reviewed Vuln_Num V-282452 Rule_ID SV-282452r1200336_rule Severity medium Rule_Title TOSS 5 must limit the maximum number of repeating characters of the same character class to four when passwords are changed. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex a password, the greater the number of possible combinations that must be tested before the password is compromised. Check_Content Verify the value of the "maxclassrepeat" option in "/etc/security/pwquality.conf" using the following command: $ grep maxclassrepeat /etc/security/pwquality.conf maxclassrepeat = 4 If the value of "maxclassrepeat" is set to "0", more than "4", or is commented out, this is a finding. Fix_Text Configure TOSS 5 to require the change of the number of repeating characters of the same character class when passwords are changed by setting the "maxclassrepeat" option. Add the following line to "/etc/security/pwquality.conf" conf (or modify the line to have the required value): maxclassrepeat = 4 Not_Reviewed Vuln_Num V-282453 Rule_ID SV-282453r1200339_rule Severity medium Rule_Title TOSS 5 must limit the maximum number of repeating characters to three when passwords are changed. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex a password, the greater the number of possible combinations that must be tested before the password is compromised. Check_Content Verify the value of the "maxrepeat" option in "/etc/security/pwquality.conf" using the following command: $ grep maxrepeat /etc/security/pwquality.conf maxrepeat = 3 If the value of "maxrepeat" is set to more than "3", or is commented out, this is a finding. Fix_Text Configure TOSS 5 to require changing the number of repeating consecutive characters when passwords are changed by setting the "maxrepeat" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): maxrepeat = 3 Not_Reviewed Vuln_Num V-282454 Rule_ID SV-282454r1200342_rule Severity medium Rule_Title TOSS 5 must require the change of at least four character classes when passwords are changed. Vuln_Discuss Use of a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex a password, the greater the number of possible combinations that must be tested before the password is compromised. Check_Content Verify the value of the "minclass" option in "/etc/security/pwquality.conf" using the following command: $ grep minclass /etc/security/pwquality.conf minclass = 4 If the value of "minclass" is set to less than "4", or is commented out, this is a finding. Fix_Text Configure TOSS 5 to require the change of at least four character classes when passwords are changed by setting the "minclass" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): minclass = 4 Not_Reviewed Vuln_Num V-282455 Rule_ID SV-282455r1201382_rule Severity medium Rule_Title TOSS 5 password-auth must be configured to use a sufficient number of hashing rounds. Vuln_Discuss Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using more hashing rounds makes password cracking attacks more difficult. Satisfies: SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061 Check_Content Verify the number of rounds for the password hashing algorithm is configured using the following command: $ sudo grep rounds /etc/pam.d/password-auth password sufficient pam_unix.so sha512 rounds=5000 If a matching line is not returned or "rounds" is less than "5000", this is a finding. Fix_Text Configure Red Hat Enterprise Linux 9 to use 5000 hashing rounds for hashing passwords. Add or modify the following line in "/etc/pam.d/password-auth" and set "rounds" to "5000". password sufficient pam_unix.so sha512 rounds=5000 Not_Reviewed Vuln_Num V-282456 Rule_ID SV-282456r1201574_rule Severity medium Rule_Title TOSS 5 system-auth must be configured to use a sufficient number of hashing rounds. Vuln_Discuss Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using more hashing rounds makes password cracking attacks more difficult. Satisfies: SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061 Check_Content Verify the number of rounds for the password hashing algorithm is configured using the following command: $ sudo grep rounds /etc/pam.d/system-auth password sufficient pam_unix.so sha512 rounds=5000 If a matching line is not returned or "rounds" is less than "5000", this is a finding. Fix_Text Configure Red Hat Enterprise Linux 9 to use 5000 hashing rounds for hashing passwords. Add or modify the following line in "/etc/pam.d/system-auth" and set "rounds" to "5000". password sufficient pam_unix.so sha512 rounds=5000' Not_Reviewed Vuln_Num V-282457 Rule_ID SV-282457r1200351_rule Severity medium Rule_Title TOSS 5 must be configured so that user and group account administration utilities are configured to store only encrypted representations of passwords. Vuln_Discuss Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the "crypt_style" configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult. Check_Content Verify the user and group account administration utilities are configured to store only encrypted representations of passwords using the following command: # grep crypt /etc/libuser.conf crypt_style = sha512 If the "crypt_style" variable is not set to "sha512", is not in the defaults section, is commented out, or does not exist, this is a finding. Fix_Text Configure TOSS 5 to use the SHA-512 algorithm for password hashing. Add or change the following line in the "[default]" section of "/etc/libuser.conf" file: crypt_style = sha512 Not_Reviewed Vuln_Num V-282458 Rule_ID SV-282458r1200354_rule Severity medium Rule_Title TOSS 5 must be configured to use the shadow file to store only encrypted representations of passwords. Vuln_Discuss Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. This setting ensures user and group account administration utilities are configured to store only encrypted representations of passwords. Additionally, the "crypt_style" configuration option ensures the use of a strong hashing algorithm that makes password cracking attacks more difficult. Check_Content Verify the system's shadow file is configured to store only encrypted representations of passwords with a hash value of "SHA512" using the following command: # grep -i encrypt_method /etc/login.defs ENCRYPT_METHOD SHA512 If "ENCRYPT_METHOD" does not have a value of "SHA512", or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to store only SHA-512 encrypted representations of passwords. Add or update the following line in the "/etc/login.defs" file: ENCRYPT_METHOD SHA512 Not_Reviewed Vuln_Num V-282459 Rule_ID SV-282459r1200357_rule Severity medium Rule_Title TOSS 5 shadow password suite must be configured to use a sufficient number of hashing rounds. Vuln_Discuss Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Passwords that are encrypted with a weak algorithm are no more protected than if they are kept in plain text. Using more hashing rounds makes password cracking attacks more difficult. Satisfies: SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061 Check_Content Verify TOSS 5 has a minimum number of hash rounds configured using the following command: $ grep -i sha_crypt /etc/login.defs If "SHA_CRYPT_MIN_ROUNDS" or "SHA_CRYPT_MAX_ROUNDS" is less than "5000", this is a finding. Fix_Text Configure TOSS 5 to encrypt all stored passwords with a strong cryptographic hash. Edit/modify the following line in the "/etc/login.defs" file and set "SHA_CRYPT_MIN_ROUNDS" to a value no lower than "5000": SHA_CRYPT_MIN_ROUNDS 5000 Not_Reviewed Vuln_Num V-282460 Rule_ID SV-282460r1200360_rule Severity medium Rule_Title TOSS 5 must employ FIPS 140-3-approved cryptographic hashing algorithms for all stored passwords. Vuln_Discuss The system must use a strong hashing algorithm to store the password. Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. Satisfies: SRG-OS-000073-GPOS-00041, SRG-OS-000120-GPOS-00061 Check_Content Verify the interactive user account passwords are using a strong password hash using the following command: $ sudo cut -d: -f2 /etc/shadow $6$kcOnRq/5$NUEYPuyL.wghQwWssXRcLRFiiru7f5JPV6GaJhNC2aK5F3PZpE/BCCtwrxRc/AInKMNX3CdMw11m9STiql12f/ Password hashes "!" or "*" indicate inactive accounts not available for login and are not evaluated. If any interactive user password hash does not begin with "$6", this is a finding. Fix_Text Lock all interactive user accounts not using SHA-512 hashing until the passwords can be regenerated with SHA-512. Not_Reviewed Vuln_Num V-282461 Rule_ID SV-282461r1200363_rule Severity medium Rule_Title The TOSS 5 pam_unix.so module must be configured in the password-auth file to use a FIPS 140-3-approved cryptographic hashing algorithm for system authentication. Vuln_Discuss Unapproved mechanisms that are used for authentication to the cryptographic module are not verified and; therefore, cannot be relied upon to provide confidentiality or integrity, and DOD data may be compromised. TOSS 5 systems using encryption are required to use FIPS-compliant mechanisms for authenticating to cryptographic modules. FIPS 140-3 is the current standard for validating that mechanisms used to access cryptographic modules use authentication that meets DOD requirements. This allows for Security Levels 1, 2, 3, or 4 for use on a general-purpose computing system. Check_Content Verify the pam_unix.so module is configured to use sha512 in /etc/pam.d/password-auth using the following command: $ grep "^password.*pam_unix.so.*sha512" /etc/pam.d/password-auth password sufficient pam_unix.so sha512 If "sha512" is missing, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to use a FIPS 140-3-approved cryptographic hashing algorithm for system authentication. Edit or modify the following line in the "/etc/pam.d/password-auth" file to include the sha512 option for pam_unix.so: password sufficient pam_unix.so sha512 Not_Reviewed Vuln_Num V-282462 Rule_ID SV-282462r1200366_rule Severity medium Rule_Title TOSS 5 must not have the rsh-server package installed. Vuln_Discuss Passwords must be protected at all times, and encryption is the standard method for protecting passwords. If passwords are not encrypted, they can be plainly read (i.e., clear text) and easily compromised. The rsh-server service provides an unencrypted remote access service that does not provide for the confidentiality and integrity of user passwords or the remote session and has very weak authentication. Check_Content Determine if the rsh-server package is installed using the following command: $ sudo yum list installed rsh-server If the rsh-server package is installed, this is a finding. Fix_Text Configure the operating system to disable nonessential capabilities by removing the rsh-server package from the system using the following command: $ sudo yum remove rsh-server Not_Reviewed Vuln_Num V-282463 Rule_ID SV-282463r1200369_rule Severity medium Rule_Title TOSS 5 passwords for new users or password changes must have a 24 hours minimum password lifetime restriction in /etc/login.defs. Vuln_Discuss Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, then the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. Setting the minimum password age protects against users cycling back to a favorite password after satisfying the password reuse requirement. Check_Content Verify TOSS 5 enforces 24 hours as the minimum password lifetime for new user accounts. Check for the value of "PASS_MIN_DAYS" in "/etc/login.defs" using the following command: $ grep -i pass_min_days /etc/login.defs PASS_MIN_DAYS 1 If the "PASS_MIN_DAYS" parameter value is not "1" or greater, or is commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce 24 hours as the minimum password lifetime. Add the following line in "/etc/login.defs" (or modify the line to have the required value): PASS_MIN_DAYS 1 Not_Reviewed Vuln_Num V-282464 Rule_ID SV-282464r1200372_rule Severity medium Rule_Title TOSS 5 passwords must have a 24 hours minimum password lifetime restriction in /etc/shadow. Vuln_Discuss Enforcing a minimum password lifetime helps to prevent repeated password changes to defeat the password reuse or history enforcement requirement. If users are allowed to immediately and continually change their password, the password could be repeatedly changed in a short period of time to defeat the organization's policy regarding password reuse. Check_Content Verify TOSS 5 has configured the minimum time period between password changes for each user account as one day or greater using the following command: $ sudo awk -F: '$4 < 1 {print $1 " " $4}' /etc/shadow If any results are returned that are not associated with a system account, this is a finding. Fix_Text Configure noncompliant accounts to enforce a 24 hour minimum password lifetime: $ sudo passwd -n 1 [user] Not_Reviewed Vuln_Num V-282465 Rule_ID SV-282465r1200375_rule Severity medium Rule_Title TOSS 5 user account passwords for new users or password changes must have a 60-day maximum password lifetime restriction in /etc/login.defs. Vuln_Discuss Any password, no matter how complex, can eventually be cracked; therefore, passwords must be changed periodically. If the operating system does not limit the lifetime of passwords and force users to change their passwords, there is the risk that the operating system passwords could be compromised. Setting the password maximum age ensures users are required to periodically change their passwords. Requiring shorter password lifetimes increases the risk of users writing down the password in a convenient location subject to physical compromise. Check_Content Verify TOSS 5 enforces a 60-day maximum password lifetime for new user accounts using the following command: $ grep -i pass_max_days /etc/login.defs PASS_MAX_DAYS 60 If the "PASS_MAX_DAYS" parameter value is greater than "60" or commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce a 60-day maximum password lifetime. Add or modify the following line in the "/etc/login.defs" file: PASS_MAX_DAYS 60 Not_Reviewed Vuln_Num V-282466 Rule_ID SV-282466r1200378_rule Severity medium Rule_Title TOSS 5 user account passwords must have a 60-day maximum password lifetime restriction. Vuln_Discuss Any password, no matter how complex, can eventually be cracked; therefore, passwords must be changed periodically. If TOSS 5 does not limit the lifetime of passwords and force users to change their passwords, there is the risk that TOSS 5 passwords could be compromised. Check_Content Check whether the maximum time period for existing passwords is restricted to 60 days with the following commands: $ sudo awk -F: '$5 > 60 {print $1 "" "" $5}' /etc/shadow $ sudo awk -F: '$5 <= 0 {print $1 "" "" $5}' /etc/shadow If any results are returned that are not associated with a system account, this is a finding. Fix_Text Configure noncompliant accounts to enforce a 60-day maximum password lifetime restriction. passwd -x 60 [user] Not_Reviewed Vuln_Num V-282467 Rule_ID SV-282467r1200381_rule Severity medium Rule_Title TOSS 5 passwords must be created with a minimum of 15 characters. Vuln_Discuss The shorter the password, the lower the number of possible combinations that must be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to increase exponentially the time and/or resources required to compromise the password. TOSS 5 uses "pwquality" as a mechanism to enforce password complexity. Configurations are set in the "etc/security/pwquality.conf" file. The "minlen", sometimes noted as minimum length, acts as a "score" of complexity based on the credit components of the "pwquality" module. By setting the credit components to a negative value, not only will those components be required, but they will not count toward the total "score" of "minlen". This will enable "minlen" to require a 15-character minimum. The DOD minimum password requirement is 15 characters. Check_Content Verify TOSS 5 enforces a minimum 15-character password length using the following command: $ grep minlen /etc/security/pwquality.conf minlen = 15 If the command does not return a "minlen" value of "15" or greater, does not return a line, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce a minimum 15-character password length. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): minlen = 15 Not_Reviewed Vuln_Num V-282468 Rule_ID SV-282468r1200384_rule Severity medium Rule_Title TOSS 5 passwords, for new users, must have a minimum of 15 characters. Vuln_Discuss The shorter the password, the lower the number of possible combinations that must be tested before the password is compromised. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password length is one factor of several that helps to determine strength and how long it takes to crack a password. Use of more characters in a password helps to increase exponentially the time and/or resources required to compromise the password. The DOD minimum password requirement is 15 characters. Check_Content Verify TOSS 5 enforces a minimum 15-character password length for new user accounts using the following command: $ sudo grep -i pass_min_len /etc/login.defs PASS_MIN_LEN 15 If the command does not return a "PASS_MIN_LEN" value of "15" or greater, does not return a line, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce a minimum 15-character password length for new user accounts. Add or modify the following line in the "/etc/login.defs" file: PASS_MIN_LEN 15 Not_Reviewed Vuln_Num V-282470 Rule_ID SV-282470r1201601_rule Severity high Rule_Title TOSS 5 must require a unique superuser name upon booting into single-user and maintenance modes. Vuln_Discuss Having a nondefault grub superuser username makes password-guessing attacks less effective. Check_Content Verify the boot loader superuser account has been set using the following command: $ sudo grep -A1 "superusers" /etc/grub2.cfg set superusers="<superusers-account>" export superusers The <superusers-account> is the actual account name, which is different from common names like "root", "admin", or "administrator". If superusers contains easily guessable usernames, this is a finding. Fix_Text Configure TOSS 5 to have a unique username for the grub superuser account. Edit the "/etc/grub.d/01_users" file and add or modify the following lines in the "### BEGIN /etc/grub.d/01_users ###" section: set superusers="superusers-account" export superusers Once the superuser account has been added, update the grub.cfg file using the following command: $ sudo grubby --update-kernel=ALL Not_Reviewed Vuln_Num V-282471 Rule_ID SV-282471r1200393_rule Severity medium Rule_Title TOSS 5 must require authentication to access emergency mode. Vuln_Discuss To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DOD-approved PKIs, all DOD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. This requirement prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password. Check_Content Verify TOSS 5 requires authentication for emergency mode using the following command: $ grep sulogin /usr/lib/systemd/system/emergency.service ExecStart=-/usr/lib/systemd/systemd-sulogin-shell emergency If this line is not returned, or is commented out, this is a finding. If the output is different, this is a finding. Fix_Text Configure TOSS 5 to require authentication for emergency mode. Add or modify the following line in the "/usr/lib/systemd/system/emergency.service" file: ExecStart=-/usr/lib/systemd/systemd-sulogin-shell emergency Not_Reviewed Vuln_Num V-282472 Rule_ID SV-282472r1200396_rule Severity medium Rule_Title TOSS 5 must require authentication to access single-user mode. Vuln_Discuss To mitigate the risk of unauthorized access to sensitive information by entities that have been issued certificates by DOD-approved PKIs, all DOD systems (e.g., web servers and web portals) must be properly configured to incorporate access control methods that do not rely solely on the possession of a certificate for access. Successful authentication must not automatically give an entity access to an asset or security boundary. Authorization procedures and controls must be implemented to ensure each authenticated entity also has a validated and current authorization. Authorization is the process of determining whether an entity, once authenticated, is permitted to access a specific asset. Information systems use access control policies and enforcement mechanisms to implement this requirement. This requirement prevents attackers with physical access from trivially bypassing security on the machine and gaining root access. Such accesses are further prevented by configuring the bootloader password. Check_Content Verify TOSS 5 requires authentication for single-user mode using the following command: $ grep sulogin /usr/lib/systemd/system/rescue.service ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue If this line is not returned, or is commented out, this is a finding. Fix_Text Configure TOSS 5 to require authentication for single-user mode. Add or modify the following line in the "/usr/lib/systemd/system/rescue.service" file: ExecStart=-/usr/lib/systemd/systemd-sulogin-shell rescue Not_Reviewed Vuln_Num V-282473 Rule_ID SV-282473r1200399_rule Severity low Rule_Title TOSS 5 must enable mitigations against processor-based vulnerabilities. Vuln_Discuss Kernel page-table isolation is a kernel feature that mitigates the Meltdown security vulnerability and hardens the kernel against attempts to bypass kernel address space layout randomization (KASLR). Satisfies: SRG-OS-000095-GPOS-00049, SRG-OS-000433-GPOS-00193 Check_Content Verify TOSS 5 enables kernel page-table isolation using the following command: $ sudo grubby --info=ALL | grep pti args="ro crashkernel=auto resume=/dev/mapper/rhel-swap rd.lvm.lv=rhel/root rd.lvm.lv=rhel/swap rhgb quiet fips=1 audit=1 audit_backlog_limit=8192 pti=on If the "pti" entry does not equal "on" or is missing, this is a finding. Fix_Text Configure TOSS 5 to enable kernel page-table isolation using the following command: $ sudo grubby --update-kernel=ALL --args="pti=on" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="pti=on" Not_Reviewed Vuln_Num V-282474 Rule_ID SV-282474r1200402_rule Severity medium Rule_Title TOSS 5 must be configured to disable the Asynchronous Transfer Mode (ATM) kernel module. Vuln_Discuss Disabling ATM protects the system against exploitation of any flaws in its implementation. Check_Content Verify TOSS 5 disables the ability to load the ATM kernel module using the following command: $ sudo grep -r atm /etc/modprobe.conf /etc/modprobe.d/* blacklist atm If the command does not return any output, or the line is commented out, and use of ATM is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the system to prevent the atm kernel module from being loaded by adding the following line to the file /etc/modprobe.d/atm.conf (or create atm.conf if it does not exist): install atm /bin/false blacklist atm Not_Reviewed Vuln_Num V-282475 Rule_ID SV-282475r1200405_rule Severity medium Rule_Title TOSS 5 must be configured to disable the Controller Area Network (CAN) kernel module. Vuln_Discuss Disabling CAN protects the system against exploitation of any flaws in its implementation. Check_Content Verify TOSS 5 disables the ability to load the "CAN" kernel module using the following command: $ sudo grep -r can /etc/modprobe.conf /etc/modprobe.d/* blacklist can If the command does not return any output, or the line is commented out, and use of CAN is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the system to prevent the "CAN" kernel module from being loaded by adding the following line to the file /etc/modprobe.d/can.conf (or create atm.conf if it does not exist): install can /bin/false blacklist can Not_Reviewed Vuln_Num V-282476 Rule_ID SV-282476r1200408_rule Severity medium Rule_Title TOSS 5 must be configured to disable the FireWire kernel module. Vuln_Discuss Disabling FireWire protects the system against exploitation of any flaws in its implementation. Check_Content Verify TOSS 5 disables the ability to load the "firewire-core" kernel module using the following command: $ sudo grep -r firewire-core /etc/modprobe.conf /etc/modprobe.d/* blacklist firewire-core If the command does not return any output, or the line is commented out, and use of firewire-core is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text To configure the system to prevent the "firewire-core" kernel module from being loaded, add the following line to the file /etc/modprobe.d/firewire-core.conf (or create firewire-core.conf if it does not exist): install firewire-core /bin/false blacklist firewire-core Not_Reviewed Vuln_Num V-282477 Rule_ID SV-282477r1200411_rule Severity medium Rule_Title TOSS 5 must disable the Stream Control Transmission Protocol (SCTP) kernel module. Vuln_Discuss It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect unused protocols can result in a system compromise. The SCTP is a transport layer protocol, designed to support the idea of message-oriented communication, with several streams of messages within one connection. Disabling SCTP protects the system against exploitation of any flaws in its implementation. Check_Content Verify TOSS 5 disables the ability to load the "sctp" kernel module using the following command: $ sudo grep -r sctp /etc/modprobe.conf /etc/modprobe.d/* blacklist sctp If the command does not return any output, or the line is commented out, and use of sctp is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text To configure the system to prevent the "sctp" kernel module from being loaded, add the following line to the file /etc/modprobe.d/sctp.conf (or create sctp.conf if it does not exist): install sctp /bin/false blacklist sctp Not_Reviewed Vuln_Num V-282478 Rule_ID SV-282478r1200414_rule Severity medium Rule_Title TOSS 5 must disable the Transparent Inter Process Communication (TIPC) kernel module. Vuln_Discuss It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Failing to disconnect unused protocols can result in a system compromise. The TIPC is a protocol that is specially designed for intra-cluster communication. It can be configured to transmit messages either on UDP or directly across Ethernet. Message delivery is sequence guaranteed, loss free and flow controlled. Disabling TIPC protects the system against exploitation of any flaws in its implementation. Check_Content Verify TOSS 5 disables the ability to load the "tipc" kernel module using the following command: $ sudo grep -r tipc /etc/modprobe.conf /etc/modprobe.d/* blacklist tipc If the command does not return any output, or the line is commented out, and use of TIPC is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text To configure the system to prevent the "tipc" kernel module from being loaded, add the following line to the file /etc/modprobe.d/tipc.conf (or create tipc.conf if it does not exist): install tipc /bin/false blacklist tipc Not_Reviewed Vuln_Num V-282479 Rule_ID SV-282479r1200417_rule Severity medium Rule_Title TOSS 5 must not have the ypserv package installed. Vuln_Discuss The NIS service provides an unencrypted authentication service, which does not provide for the confidentiality and integrity of user passwords or the remote session. Removing the "ypserv" package decreases the risk of the accidental (or intentional) activation of NIS or NIS+ services. Check_Content Verify the "ypserv" package is not installed using the following command: $ sudo dnf list --installed ypserv Error: No matching Packages to list If the "ypserv" package is installed, this is a finding. Fix_Text Remove the "ypserv" package using the following command: $ sudo dnf remove ypserv Not_Reviewed Vuln_Num V-282480 Rule_ID SV-282480r1200420_rule Severity medium Rule_Title TOSS 5 must not have the rsh-server package installed. Vuln_Discuss The "rsh-server" service provides unencrypted remote access service, which does not provide for the confidentiality and integrity of user passwords or the remote session and has very weak authentication. If a privileged user were to login using this service, the privileged user password could be compromised. The "rsh-server" package provides several obsolete and insecure network services. Removing it decreases the risk of accidental (or intentional) activation of those services. Check_Content Verify the "rsh-server" package is not installed using the following command: $ sudo dnf list --installed rsh-server Error: No matching Packages to list If the "rsh-server" package is installed, this is a finding. Fix_Text Remove the "rsh-server" package using the following command: $ sudo dnf remove rsh-server Not_Reviewed Vuln_Num V-282481 Rule_ID SV-282481r1200423_rule Severity medium Rule_Title TOSS 5 must not have the telnet-server package installed. Vuln_Discuss It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities are often overlooked and therefore, may remain unsecure. They increase the risk to the platform by providing additional attack vectors. The telnet service provides an unencrypted remote access service, which does not provide for the confidentiality and integrity of user passwords or the remote session. If a privileged user were to login using this service, the privileged user password could be compromised. Removing the "telnet-server" package decreases the risk of accidental (or intentional) activation of the telnet service. Check_Content Verify the "telnet-server" package is not installed using the following command: $ sudo dnf list --installed telnet-server Error: No matching Packages to list If the "telnet-server" package is installed, this is a finding. Fix_Text Remove the "telnet-server" package using the following command: $ sudo dnf remove telnet-server Not_Reviewed Vuln_Num V-282482 Rule_ID SV-282482r1200426_rule Severity medium Rule_Title TOSS 5 must not have the iprutils package installed. Vuln_Discuss It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services, provided by default, may not be necessary to support essential organizational operations (e.g., key missions, functions). The iprutils package provides a suite of utilities to manage and configure SCSI devices supported by the ipr SCSI storage device driver. Check_Content Verify the "iprutils" package is not installed using the following command: $ sudo dnf list --installed iprutils Error: No matching Packages to list If the "iprutils" package is installed and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Remove the "iprutils" package using the following command: $ sudo dnf remove iprutils Not_Reviewed Vuln_Num V-282483 Rule_ID SV-282483r1200429_rule Severity low Rule_Title TOSS 5 must disable mounting of cramfs. Vuln_Discuss It is detrimental for operating systems to provide, or install by default, functionality exceeding requirements or mission objectives. These unnecessary capabilities or services are often overlooked and therefore may remain unsecured. They increase the risk to the platform by providing additional attack vectors. Removing support for unneeded file system types reduces the local attack surface of the server. Compressed ROM/RAM file system (or cramfs) is a read-only file system designed for simplicity and space-efficiency. It is mainly used in embedded and small-footprint systems. Check_Content Verify TOSS 5 disables the ability to load the "cramfs" kernel module using the following command: $ sudo grep -r cramfs /etc/modprobe.conf /etc/modprobe.d/* blacklist cramfs If the command does not return any output, or the line is commented out, and use of "cramfs" is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text To configure the system to prevent the "cramfs" kernel module from being loaded, add the following line to the file "/etc/modprobe.d/blacklist.conf" (or create blacklist.conf if it does not exist): install cramfs /bin/false blacklist cramfs Not_Reviewed Vuln_Num V-282484 Rule_ID SV-282484r1201332_rule Severity low Rule_Title TOSS 5 must disable network management of the chrony daemon. Vuln_Discuss Not exposing the management interface of the chrony daemon on the network diminishes the attack space. Satisfies: SRG-OS-000095-GPOS-00049, SRG-OS-000096-GPOS-00050 Check_Content Verify TOSS 5 disables network management of the chrony daemon using the following command: $ grep -w cmdport /etc/chrony.conf cmdport 0 If the "cmdport" option is not set to "0", is commented out, or is missing, this is a finding. Fix_Text Configure TOSS 5 to disable network management of the chrony daemon by adding/modifying the following line in the "/etc/chrony.conf" file: cmdport 0 Not_Reviewed Vuln_Num V-282485 Rule_ID SV-282485r1200435_rule Severity medium Rule_Title TOSS 5 must have the firewalld package installed. Vuln_Discuss "firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. TOSS 5 functionality (e.g., SSH) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000298-GPOS-00116 Check_Content Run the following command to determine if the "firewalld" package is installed: $ sudo dnf list --installed firewalld Example output: firewalld.noarch 1.0.0-4.el9 If the "firewalld" package is not installed, this is a finding. Fix_Text Install the "firewalld" package using the following command: $ sudo dnf install firewalld Not_Reviewed Vuln_Num V-282486 Rule_ID SV-282486r1200438_rule Severity medium Rule_Title The firewalld service on TOSS 5 must be active. Vuln_Discuss "firewalld" provides an easy and effective way to block/limit remote access to the system via ports, services, and protocols. Remote access services, such as those providing remote access to network devices and information systems, which lack automated control capabilities, increase risk and make remote user access management difficult at best. Remote access is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. TOSS 5 functionality (e.g., RDP) must be capable of taking enforcement action if the audit reveals unauthorized activity. Automated control of remote access sessions allows organizations to ensure ongoing compliance with remote access policies by enforcing connection rules of remote access applications on a variety of information system components (e.g., servers, workstations, notebook computers, smartphones, and tablets). Satisfies: SRG-OS-000096-GPOS-00050, SRG-OS-000297-GPOS-00115 Check_Content Verify "firewalld" is active using the following command: $ systemctl is-active firewalld active If the "firewalld" service is not active, this is a finding. Fix_Text Enable the "firewalld" service using the following command: $ sudo systemctl enable --now firewalld Not_Reviewed Vuln_Num V-282487 Rule_ID SV-282487r1200441_rule Severity medium Rule_Title TOSS 5 must control remote access methods. Vuln_Discuss To prevent unauthorized device connection, unauthorized information transfer, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary physical and logical ports/protocols on information systems. Operating systems are capable of providing a wide variety of functions and services. Some of the functions and services provided by default may not be necessary to support essential organizational operations. Additionally, it is sometimes convenient to provide multiple services from a single component (e.g., VPN and IPS); however, doing so increases risk over limiting the services provided by one component. To support the requirements and principles of least functionality, the operating system must support the organizational requirements, providing only essential capabilities and limiting the use of ports, protocols, and/or services to only those required, authorized, and approved to conduct official business. Check_Content Inspect the list of enabled firewall ports and verify they are configured correctly using the following command: $ sudo firewall-cmd --list-all Ask the system administrator for the site or program Ports, Protocols, and Services Management Component Local Service Assessment (PPSM CLSA). Verify the services allowed by the firewall match the PPSM CLSA, or other applicable documentation approved by the information system security officer (ISSO). If there are additional ports, protocols, or services that are not in the PPSM CLSA, or there are ports, protocols, or services that are prohibited by the PPSM Category Assurance List (CAL), or there are no firewall rules configured, this is a finding. Fix_Text Configure TOSS 5 to allow approved settings and/or running services to comply with the PPSM CLSA for the site or program and the PPSM CAL, or other applicable documentation approved by the ISSO. To open a port for a service, configure "firewalld" using the following command: $ sudo firewall-cmd --permanent --add-port=port_number/tcp or $ sudo firewall-cmd --permanent --add-service=service_name Not_Reviewed Vuln_Num V-282488 Rule_ID SV-282488r1200444_rule Severity medium Rule_Title TOSS 5 must be configured to prohibit or restrict the use of functions, ports, protocols, and/or services, as defined in the Ports, Protocols, and Services Management (PPSM) Category Assignments List (CAL) and vulnerability assessments. Vuln_Discuss To prevent unauthorized connection of devices, unauthorized transfer of information, or unauthorized tunneling (i.e., embedding of data types within data types), organizations must disable or restrict unused or unnecessary ports, protocols, and services on information systems. Check_Content Inspect the firewall configuration and running services to verify it is configured to prohibit or restrict the use of functions, ports, protocols, and/or services that are unnecessary or prohibited. Check which services are currently active using the following command: $ sudo firewall-cmd --list-all-zones custom (active) target: DROP icmp-block-inversion: no interfaces: ens33 sources: services: dhcpv6-client dns http https ldaps rpc-bind ssh ports: masquerade: no forward-ports: icmp-blocks: rich rules: Ask the system administrator for the site or program PPSM Component Local Service Assessment (CLSA). Verify the services allowed by the firewall match the PPSM CLSA, or other applicable documentation approved by the information system security officer (ISSO). If there are additional ports, protocols, or services that are not in the PPSM CLSA; or there are ports, protocols, or services that are prohibited by the PPSM CAL, this is a finding. Fix_Text Update the host's firewall settings and/or running services to comply with the PPSM CLSA for the site or program and the PPSM CAL, or other applicable documentation approved by the ISSO. Run the following command to load the newly created rule(s): $ sudo firewall-cmd --reload Not_Reviewed Vuln_Num V-282489 Rule_ID SV-282489r1200447_rule Severity medium Rule_Title TOSS 5 duplicate User IDs (UIDs) must not exist for interactive users. Vuln_Discuss To ensure accountability and prevent unauthenticated access, interactive users must be identified and authenticated to prevent potential misuse and compromise of the system. Satisfies: SRG-OS-000104-GPOS-00051, SRG-OS-000121-GPOS-00062 Check_Content Verify TOSS 5 contains no duplicate UIDs for interactive users using the following command: $ sudo awk -F ":" 'list[$3]++{print $1, $3}' /etc/passwd If output is produced and the accounts listed are interactive user accounts, this is a finding. Fix_Text Edit the file "/etc/passwd" and provide each interactive user account that has a duplicate UID with a unique UID. Not_Reviewed Vuln_Num V-282490 Rule_ID SV-282490r1200450_rule Severity medium Rule_Title All TOSS 5 interactive users must have a primary group that exists. Vuln_Discuss If a user is assigned the Group Identifier (GID) of a group that does not exist on the system, and a group with the GID is subsequently created, the user may have unintended rights to any files associated with the group. Check_Content Verify all TOSS 5 interactive users have a valid GID using the following command: $ sudo pwck -qr If the system has any interactive users with duplicate GIDs, this is a finding. Fix_Text Configure the system so all GIDs referenced in "/etc/passwd" are defined in "/etc/group". Edit the file "/etc/passwd" and ensure every user's GID is a valid GID. Not_Reviewed Vuln_Num V-282491 Rule_ID SV-282491r1200453_rule Severity medium Rule_Title TOSS 5 groups must have unique Group ID (GID). Vuln_Discuss To ensure accountability and prevent unauthenticated access, groups must be identified uniquely to prevent potential misuse and compromise of the system. Check_Content Verify TOSS 5 contains no duplicate GIDs for interactive users using the following command: $ cut -d : -f 3 /etc/group | uniq -d If the system has duplicate GIDs, this is a finding. Fix_Text Edit the file "/etc/group" and provide each group that has a duplicate GID with a unique GID. Not_Reviewed Vuln_Num V-282492 Rule_ID SV-282492r1200456_rule Severity medium Rule_Title TOSS 5 must have the openssl-pkcs11 package installed. Vuln_Discuss Without the use of multifactor authentication, the ease of access to privileged functions is greatly increased. Multifactor authentication requires using two or more factors to achieve authentication. A privileged account is defined as an information system account with authorizations of a privileged user. The DOD common access card (CAC) with DOD-approved PKI is an example of multifactor authentication. Satisfies: SRG-OS-000105-GPOS-00052, SRG-OS-000106-GPOS-00053, SRG-OS-000046-GPOS-00022, SRG-OS-000107-GPOS-00054, SRG-OS-000108-GPOS-00055 Check_Content Verify TOSS 5 has the "openssl-pkcs11" package installed using the following command: $ sudo dnf list --installed openssl-pkcs11 Example output: openssl-pkcs.i686 0.4.11-7.el9 openssl-pkcs.x86_64 0.4.11-7.el9 If the "openssl-pkcs11" package is not installed, this is a finding. Fix_Text The "openssl-pkcs11" package can be installed using the following command: $ sudo dnf install openssl-pkcs11 Not_Reviewed Vuln_Num V-282493 Rule_ID SV-282493r1200459_rule Severity high Rule_Title TOSS 5 SSHD must not allow blank or null passwords. Vuln_Discuss If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. Check_Content Verify TOSS 5 remote access using SSH prevents logging on with a blank password using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*permitemptypasswords' PermitEmptyPassword no If the "PermitEmptyPassword" keyword is set to "yes", is missing, or is commented out, this is a finding. Fix_Text Configure the system to prevent SSH users from logging on with blank passwords by editing the following line in "etc/ssh/sshd_config": PermitEmptyPasswords no Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282494 Rule_ID SV-282494r1200462_rule Severity medium Rule_Title TOSS 5 must not permit direct logins to the root account using remote access via SSH. Vuln_Discuss Even though the communications channel may be encrypted, an additional layer of security is gained by extending the policy of not logging directly on as root. In addition, logging in with a user-specific account provides individual accountability of actions performed on the system and also helps to minimize direct attack attempts on root's password. Check_Content Verify TOSS 5 remote access using SSH prevents users from logging on directly as "root" using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*permitrootlogin' PermitRootLogin no If the "PermitRootLogin" keyword is set to "yes", is missing, or is commented out, this is a finding. Fix_Text Configure the system to prevent SSH users from logging on directly as "root" by adding or modifying the following line in "/etc/ssh/sshd_config": PermitRootLogin no Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282497 Rule_ID SV-282497r1200471_rule Severity medium Rule_Title TOSS 5 file system automount function must be disabled unless required. Vuln_Discuss An authentication process resists replay attacks if it is impractical to achieve a successful authentication by recording and replaying a previous authentication message. Check_Content Verify TOSS 5 file system automount function has been disabled using the following command: $ sudo systemctl is-enabled autofs masked If the returned value is not "masked", "disabled", "Failed to get unit file state for autofs.service for autofs", or "enabled", and is not documented as operational requirement with the information system security officer (ISSO), this is a finding. Fix_Text Configure TOSS 5 to disable the ability to automount devices. Disable the "autofs" service using the following command: $ sudo systemctl mask --now autofs.service Not_Reviewed Vuln_Num V-282498 Rule_ID SV-282498r1200474_rule Severity medium Rule_Title TOSS 5 must disable the graphical user interface automount function unless required. Vuln_Discuss Automatically mounting file systems permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163 Check_Content Verify TOSS 5 disables the graphical user interface automount function using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. $ gsettings get org.gnome.desktop.media-handling automount-open false If "automount-open" is set to "true" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the GNOME desktop to disable automated mounting of removable media. The dconf settings can be edited in the /etc/dconf/db/* location. Update the [org/gnome/desktop/media-handling] section of the "/etc/dconf/db/local.d/00-security-settings" database file and add or update the following lines: [org/gnome/desktop/media-handling] automount-open=false Update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282499 Rule_ID SV-282499r1200477_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the disabling of the graphical user interface automount function. Vuln_Discuss A nonprivileged account is any operating system account with authorizations of a nonprivileged user. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163 Check_Content Verify TOSS 5 disables ability of the user to override the graphical user interface automount setting. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using by running the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Verify the automount setting is locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". Modify this path if using a database other than "local". $ grep 'automount-open' /etc/dconf/db/local.d/locks/* /org/gnome/desktop/media-handling/automount-open If the command does not return at least the example result, this is a finding. Fix_Text Configure the GNOME desktop to not allow a user to change the setting that disables automated mounting of removable media. Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user modification: /org/gnome/desktop/media-handling/automount-open Update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282500 Rule_ID SV-282500r1200480_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the disabling of the graphical user interface autorun function. Vuln_Discuss Techniques used to address this include protocols using nonces (e.g., numbers generated for a specific one-time use) or challenges (e.g., TLS, WS_Security). Additional techniques include time-synchronous or challenge-response one-time authenticators. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163 Check_Content Verify TOSS 5 disables the user's ability to override the graphical user interface autorun setting. Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using by running the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that the automount setting is locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ grep 'autorun-never' /etc/dconf/db/local.d/locks/* /org/gnome/desktop/media-handling/autorun-never If the command does not return at least the example result, this is a finding. Fix_Text Configure the GNOME desktop to not allow a user to change the setting that disables autorun on removable media. Add the following line to "/etc/dconf/db/local.d/locks/00-security-settings-lock" to prevent user modification: /org/gnome/desktop/media-handling/autorun-never Update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282501 Rule_ID SV-282501r1200483_rule Severity medium Rule_Title TOSS 5 must be configured to disable USB mass storage. Vuln_Discuss USB mass storage permits easy introduction of unknown devices, thereby facilitating malicious activity. Satisfies: SRG-OS-000114-GPOS-00059, SRG-OS-000378-GPOS-00163, SRG-OS-000690-GPOS-00140 Check_Content Verify TOSS 5 disables the ability to load the USB Storage kernel module using the following command: $ sudo grep -r usb-storage /etc/modprobe.conf /etc/modprobe.d/* blacklist usb-storage If the command does not return any output, the line is commented out, and use of USB Storage is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the system to prevent the usb-storage kernel module from being loaded by adding the following line to the file /etc/modprobe.d/usb-storage.conf (or create usb-storage.conf if it does not exist): install usb-storage /bin/false blacklist usb-storage Not_Reviewed Vuln_Num V-282502 Rule_ID SV-282502r1200486_rule Severity medium Rule_Title TOSS 5 must disable account identifiers (individuals, groups, roles, and devices) after 35 days of inactivity. Vuln_Discuss Inactive identifiers pose a risk to systems and applications because attackers may exploit an inactive identifier and potentially obtain undetected access to the system. Disabling inactive accounts ensures that accounts which may not have been responsibly removed are not available to attackers who may have compromised their credentials. Owners of inactive accounts will not notice if unauthorized access to their user account has been obtained. Satisfies: SRG-OS-000118-GPOS-00060, SRG-OS-000590-GPOS-00110 Check_Content Verify TOSS 5 account identifiers (individuals, groups, roles, and devices) are disabled after 35 days of inactivity using the following command: Check the account inactivity value by performing the following command: $ sudo grep -i inactive /etc/default/useradd INACTIVE=35 If "INACTIVE" is set to "-1", a value greater than "35", or is commented out, this is a finding. Fix_Text Configure TOSS 5 to disable account identifiers after 35 days of inactivity after the password expiration. Run the following command to change the configuration for "useradd": $ sudo useradd -D -f 35 The recommendation is 35 days, but a lower value is acceptable. Not_Reviewed Vuln_Num V-282503 Rule_ID SV-282503r1200489_rule Severity medium Rule_Title TOSS 5 must use mechanisms meeting the requirements of applicable federal laws, executive orders, directives, policies, regulations, standards, and guidance for authentication to a cryptographic module. Vuln_Discuss Overriding the system crypto policy makes the behavior of Kerberos violate expectations and makes system configuration more fragmented. Check_Content Verify the symlink exists and targets the correct Kerberos crypto policy, using the following command: file /etc/crypto-policies/back-ends/krb5.config If command output shows the following line, Kerberos is configured to use the systemwide crypto policy: /etc/crypto-policies/back-ends/krb5.config: symbolic link to /usr/share/crypto-policies/FIPS/krb5.txt If the symlink does not exist or points to a different target, this is a finding. Fix_Text Configure Kerberos to use system crypto policy. Create a symlink pointing to system crypto policy in the Kerberos configuration using the following command: $ sudo ln -s /etc/crypto-policies/back-ends/krb5.config /usr/share/crypto-policies/FIPS/krb5.txt Not_Reviewed Vuln_Num V-282504 Rule_ID SV-282504r1200492_rule Severity high Rule_Title TOSS 5 must enable the Pluggable Authentication Module (PAM) interface for SSHD. Vuln_Discuss When "UsePAM" is set to "yes", PAM runs through account and session types properly. This is important when restricted access to services based off of IP, time, or other factors of the account are needed. Additionally, this ensures users can inherit certain environment variables on login or disallow access to the server. Check_Content Verify the TOSS 5 SSHD is configured to allow for the "UsePAM" interface using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*usepam' UsePAM yes If the "UsePAM" keyword is set to "no", is missing, or is commented out, this is a finding. Fix_Text Configure the TOSS 5 SSHD to use the "UsePAM" interface, by adding or modifying the following line in "/etc/ssh/sshd_config": UsePAM yes Restart the SSH daemon for the settings to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282505 Rule_ID SV-282505r1200495_rule Severity medium Rule_Title TOSS 5 must restrict access to the kernel message buffer. Vuln_Discuss Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Restricting access to the kernel message buffer limits access to only root. This prevents attackers from gaining additional system information as a nonprivileged user. Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069 Check_Content Verify TOSS 5 is configured to restrict access to the kernel message buffer with the following commands: $ sudo sysctl kernel.dmesg_restrict kernel.dmesg_restrict = 1 If "kernel.dmesg_restrict" is not set to "1" or is missing, this is a finding. Fix_Text Configure TOSS 5 to restrict access to the kernel message buffer. Add or edit the following line in a system configuration file, in the "/etc/sysctl.d/" directory: kernel.dmesg_restrict = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282506 Rule_ID SV-282506r1200498_rule Severity medium Rule_Title TOSS 5 must prevent kernel profiling by nonprivileged users. Vuln_Discuss Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. There may be shared resources with configurable protections (e.g., files in storage) that may be assessed on specific information system components. Setting the kernel.perf_event_paranoid kernel parameter to "2" prevents attackers from gaining additional system information as a nonprivileged user. Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000138-GPOS-00069 Check_Content Verify TOSS 5 is configured to prevent kernel profiling by nonprivileged users using the following command: $ sudo sysctl kernel.perf_event_paranoid kernel.perf_event_paranoid = 2 If "kernel.perf_event_paranoid" is not set to "2" or is missing, this is a finding. Fix_Text Configure TOSS 5 to prevent kernel profiling by nonprivileged users. Add or edit the following line in a system configuration file, in the "/etc/sysctl.d/" directory: kernel.perf_event_paranoid = 2 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282507 Rule_ID SV-282507r1200501_rule Severity medium Rule_Title TOSS 5 must restrict exposed kernel pointer addresses access. Vuln_Discuss Exposing kernel pointers (through procfs or "seq_printf()") exposes kernel writeable structures, which may contain functions pointers. If a write vulnerability occurs in the kernel, allowing write access to any of this structure, the kernel can be compromised. This option disallows any program without the CAP_SYSLOG capability to get the addresses of kernel pointers by replacing them with "0". Satisfies: SRG-OS-000132-GPOS-00067, SRG-OS-000433-GPOS-00192, SRG-OS-000433-GPOS-00193 Check_Content Verify the runtime status of the "kernel.kptr_restrict" kernel parameter using the following command: $ sudo sysctl kernel.kptr_restrict kernel.kptr_restrict = 1 If "kernel.kptr_restrict" is not set to "1" or is missing, this is a finding. Fix_Text Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.kptr_restrict = 1 Reload settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282508 Rule_ID SV-282508r1200504_rule Severity medium Rule_Title TOSS 5 must disable access to network bpf system call from nonprivileged processes. Vuln_Discuss Loading and accessing the packet filters programs and maps using the "bpf()" system call has the potential of revealing sensitive information about the kernel state. Check_Content Verify TOSS 5 prevents privilege escalation through the kernel by disabling access to the bpf system call using the following command: $ sudo sysctl kernel.unprivileged_bpf_disabled kernel.unprivileged_bpf_disabled = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to prevent privilege escalation through the kernel by disabling access to the bpf syscall by adding the following line to a file, in the "/etc/sysctl.d" directory: kernel.unprivileged_bpf_disabled = 1 The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282509 Rule_ID SV-282509r1200507_rule Severity medium Rule_Title TOSS 5 must restrict usage of ptrace to descendant processes. Vuln_Discuss Unrestricted usage of ptrace allows compromised binaries to run ptrace on other processes of the user. This way, the attacker can steal sensitive information from the target processes (e.g., SSH sessions, web browser, etc.) without any additional assistance from the user (i.e., without resorting to phishing). Check_Content Verify TOSS 5 restricts usage of ptrace to descendant processes using the following command: $ sudo sysctl kernel.yama.ptrace_scope kernel.yama.ptrace_scope = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to restrict using ptrace to descendant processes by adding the following line to a file, in the "/etc/sysctl.d" directory: kernel.yama.ptrace_scope = 1 The system configuration files must be reloaded for the changes to take effect. To reload the contents of the files, run the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282510 Rule_ID SV-282510r1201302_rule Severity medium Rule_Title TOSS 5 must use a Linux Security Module configured to enforce limits on system services. Vuln_Discuss Without verification of the security functions, security functions may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. This requirement applies to operating systems performing security function verification/testing and/or systems and environments that require this functionality. Check_Content Note: At lower classification levels (CUI, Secret) where vast amounts of data are processed and a performance impact is occurring, an authorizing official can consider this requirement not applicable. Confirm that TOSS verifies the correct operation of all security functions. Determine if "SELinux" is active and in "Enforcing" mode using the following command: $ sudo getenforce Enforcing If "SELinux" is not active or not in "Enforcing" mode, this is a finding. Fix_Text Configure the operating system to verify correct operation of all security functions. Set the "SELinux" status and the "Enforcing" mode by modifying the "/etc/selinux/config" file to have the following line: SELINUX=enforcing Restart the system for the changes to take effect. Not_Reviewed Vuln_Num V-282511 Rule_ID SV-282511r1200513_rule Severity medium Rule_Title A sticky bit must be set on all TOSS 5 public directories. Vuln_Discuss Preventing unauthorized information transfers mitigates the risk of information, including encrypted representations of information, produced by the actions of prior users/roles (or the actions of processes acting on behalf of prior users/roles) from being available to any current users/roles (or current processes) that obtain access to shared system resources (e.g., registers, main memory, hard disks) after those resources have been released back to information systems. The control of information in shared resources is also commonly referred to as object reuse and residual information protection. This requirement generally applies to the design of an information technology product, but it can also apply to the configuration of particular information system components that are, or use, such products. This can be verified by acceptance/validation processes in DOD or other government agencies. Check_Content Verify all world-writable directories have the sticky bit set. Determine if all world-writable directories have the sticky bit set using the following command: $ sudo find / -type d \( -perm -0002 -a ! -perm -1000 \) -print 2>/dev/null drwxrwxrwt 7 root root 4096 Jul 26 11:19 /tmp If any of the returned directories are world-writable and do not have the sticky bit set, this is a finding. Fix_Text Configure all world-writable directories to have the sticky bit set to prevent unauthorized and unintended information transferred via shared system resources. Set the sticky bit on all world-writable directories using the command, replace "[World-Writable Directory]" with any directory path missing the sticky bit: $ chmod a+t [World-Writable Directory] Not_Reviewed Vuln_Num V-282512 Rule_ID SV-282512r1201342_rule Severity medium Rule_Title TOSS 5 must be configured to use TCP syncookies. Vuln_Discuss Denial of service (DoS) is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. Managing excess capacity ensures that sufficient capacity is available to counter flooding attacks. Employing increased capacity and service redundancy may reduce the susceptibility to some DoS attacks. Managing excess capacity may include, for example, establishing selected usage priorities, quotas, or partitioning. Satisfies: SRG-OS-000142-GPOS-00071, SRG-OS-000420-GPOS-00186 Check_Content Verify TOSS 5 is configured to use IPv4 TCP syncookies using the following command: $ sudo sysctl net.ipv4.tcp_syncookies net.ipv4.tcp_syncookies = 1 If the network parameter "ipv4.tcp_syncookies" is not equal to "1" or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to use TCP syncookies. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: net.ipv4.tcp_syncookies = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282514 Rule_ID SV-282514r1201603_rule Severity high Rule_Title TOSS 5 local disk partitions must implement cryptographic mechanisms to prevent unauthorized disclosure or modification of all information that requires at rest protection. Vuln_Discuss TOSS 5 systems handling data requiring data at rest protections must employ cryptographic mechanisms to prevent unauthorized disclosure and modification of the information at rest. Selection of a cryptographic mechanism is based on the need to protect the integrity of organizational information. The strength of the mechanism is commensurate with the security category and/or classification of the information. Organizations have the flexibility to either encrypt all information on storage devices (i.e., full disk encryption) or encrypt specific data structures (e.g., files, records, or fields). Satisfies: SRG-OS-000185-GPOS-00079, SRG-OS-000404-GPOS-00183, SRG-OS-000405-GPOS-00184 Check_Content Verify TOSS 5 prevents unauthorized disclosure or modification of all information requiring at-rest protection by using disk encryption. Note: If there is a documented and approved reason for not having data-at-rest encryption, this requirement is not applicable. Verify all system partitions are encrypted using the following command: $ blkid /dev/map per/rhel-root: UUID="67b7d7fe-de60-6fd0-befb-e6748cf97743" TYPE="crypto_LUKS" Every persistent disk partition present must be of type "crypto_LUKS". If any partitions other than the boot partition or pseudo file systems (such as /proc or /sys) or temporary file systems (that are tmpfs) are not type "crypto_LUKS", ask the administrator to indicate how the partitions are encrypted. If there is no evidence that these partitions are encrypted, this is a finding. Fix_Text Configure TOSS 5 to prevent unauthorized modification of all information at rest by using disk encryption. Encrypting a partition in an already installed system is more difficult, because existing partitions must be resized and changed. To encrypt an entire partition, dedicate a partition for encryption in the partition layout. Not_Reviewed Vuln_Num V-282516 Rule_ID SV-282516r1200528_rule Severity medium Rule_Title TOSS 5 /var/log directory must have mode 0755 or less permissive. Vuln_Discuss Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the TOSS 5 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Check_Content Verify the "/var/log" directory has a mode of "0755" or less permissive using the following command: $ ls -ld /var/log drwxr-xr-x. 16 root root 4096 July 11 11:34 /var/log If "/var/log" does not have a mode of "0755" or less permissive, this is a finding. Fix_Text Configure the "/var/log" directory to a mode of "0755" using the following command: $ sudo chmod 0755 /var/log Not_Reviewed Vuln_Num V-282517 Rule_ID SV-282517r1200531_rule Severity medium Rule_Title TOSS 5 /var/log/messages file must have mode 0640 or less permissive. Vuln_Discuss Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the TOSS 5 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Check_Content Verify the "/var/log/messages" file has a mode of "0640" or less permissive using the following command: $ ls -la /var/log/messages rw-------. 1 root root 564223 July 11 11:34 /var/log/messages If "/var/log/messages" does not have a mode of "0640" or less permissive, this is a finding. Fix_Text Configure the "/var/log/messages" file to have a mode of "0640" using the following command: $ sudo chmod 0640 /var/log/messages Not_Reviewed Vuln_Num V-282518 Rule_ID SV-282518r1200534_rule Severity medium Rule_Title TOSS 5 /var/log directory must be owned by root. Vuln_Discuss Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the TOSS 5 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Check_Content Verify the "/var/log" directory is owned by root using the following command: $ ls -ld /var/log drwxr-xr-x. 16 root root 4096 July 11 11:34 /var/log If "/var/log" does not have an owner of "root", this is a finding. Fix_Text Configure the owner of the directory "/var/log" to "root" using the following command: $ sudo chown root /var/log Not_Reviewed Vuln_Num V-282519 Rule_ID SV-282519r1200537_rule Severity medium Rule_Title TOSS 5 /var/log directory must be group-owned by root. Vuln_Discuss Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the TOSS 5 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Check_Content Verify the "/var/log" directory is group-owned by root using the following command: $ ls -ld /var/log drwxr-xr-x. 16 root root 4096 July 11 11:34 /var/log If "/var/log" does not have a group owner of "root", this is a finding. Fix_Text Configure the group owner of the directory "/var/log" to "root" using the following command: $ sudo chgrp root /var/log Not_Reviewed Vuln_Num V-282520 Rule_ID SV-282520r1200540_rule Severity medium Rule_Title TOSS 5 /var/log/messages file must be owned by root. Vuln_Discuss Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the TOSS 5 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Check_Content Verify the "/var/log/messages" file is owned by root using the following command: $ ls -la /var/log/messages rw-------. 1 root root 564223 July 11 11:34 /var/log/messages If "/var/log/messages" does not have an owner of "root", this is a finding. Fix_Text Change the owner of the "/var/log/messages" file to "root" using the following command: $ sudo chown root /var/log/messages Not_Reviewed Vuln_Num V-282521 Rule_ID SV-282521r1200543_rule Severity medium Rule_Title TOSS 5 /var/log/messages file must be group-owned by root. Vuln_Discuss Only authorized personnel should be aware of errors and the details of the errors. Error messages are an indicator of an organization's operational state or can identify the TOSS 5 system or platform. Additionally, personally identifiable information (PII) and operational information must not be revealed through error messages to unauthorized personnel or their designated representatives. The structure and content of error messages must be carefully considered by the organization and development team. The extent to which the information system is able to identify and handle error conditions is guided by organizational policy and operational requirements. Check_Content Verify the "/var/log/messages" file is group-owned by root using the following command: $ ls -la /var/log/messages rw-------. 1 root root 564223 July 11 11:34 /var/log/messages If "/var/log/messages" does not have a group owner of "root" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Change the group owner of the "/var/log/messages" file to "root" using the following command: $ sudo chgrp root /var/log/messages Not_Reviewed Vuln_Num V-282522 Rule_ID SV-282522r1200546_rule Severity medium Rule_Title TOSS 5 SSH daemon must be configured to use systemwide crypto policies. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. Check_Content Verify systemwide crypto policies are in effect using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*include' /etc/ssh/sshd_config:Include /etc/ssh/sshd_config.d/*.conf /etc/ssh/sshd_config.d/50-redhat.conf:Include /etc/crypto-policies/back-ends/opensshserver.config If "Include /etc/ssh/sshd_config.d/*.conf" or "Include /etc/crypto-policies/back-ends/opensshserver.config" are not included in the system sshd config or the file "/etc/ssh/sshd_config.d/50-redhat.conf" is missing, this is a finding. Fix_Text Configure the TOSS 5 SSH daemon to use systemwide crypto policies using the following command: $ sudo dnf reinstall openssh-server Not_Reviewed Vuln_Num V-282523 Rule_ID SV-282523r1200549_rule Severity medium Rule_Title TOSS 5 must implement DOD or other applicable U.S. Government agency-approved encryption ciphers to protect the confidentiality of SSH client connections. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. TOSS 5 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the /etc/sysconfig/sshd file. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/opensshserver.config file. Check_Content Verify systemwide crypto policies are in effect using the following command: $ sudo grep Include /etc/ssh/sshd_config /etc/ssh/sshd_config.d/* /etc/ssh/sshd_config:Include /etc/ssh/sshd_config.d/*.conf /etc/ssh/sshd_config.d/50-redhat.conf:Include /etc/crypto-policies/back-ends/opensshserver.config If "Include /etc/ssh/sshd_config.d/*.conf" or "Include /etc/crypto-policies/back-ends/opensshserver.config" are not included in the system sshd config or the file "/etc/ssh/sshd_config.d/50-redhat.conf" is missing, this is a finding. Fix_Text Configure the TOSS 5 SSH daemon to use systemwide crypto policies using the following command: $ sudo dnf reinstall openssh-clients Not_Reviewed Vuln_Num V-282524 Rule_ID SV-282524r1201364_rule Severity medium Rule_Title TOSS 5 must implement DOD or other applicable U.S. Government agency-approved encryption ciphers to protect the confidentiality of SSH server connections. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. TOSS 5 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the "/etc/sysconfig/sshd" file. The employed algorithms can be viewed in the "/etc/crypto-policies/back-ends/opensshserver.config" file. Check_Content Verify the SSH client is configured to use only ciphers employing FIPS 140-3-approved algorithms using the following command: $ sudo grep -i ciphers /etc/crypto-policies/back-ends/openssh.config Ciphers aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes256-ctr,aes128-gcm@openssh.com,aes128-ctr If the cipher entries in the "openssh.config" file have any ciphers other than "aes256-gcm@openssh.com", "chacha20-poly1305@openssh.com", "aes256-ctr,aes128-gcm@openssh.com", "aes128-ctr"; the order differs from the example above; they are missing; or commented out, this is a finding. Fix_Text Configure the TOSS 5 SSH client to only use ciphers employing FIPS 140-3-approved algorithms by updating the "/etc/crypto-policies/back-ends/openssh.config" file with the following line: Ciphers aes256-gcm@openssh.com,chacha20-poly1305@openssh.com,aes256-ctr,aes128-gcm@openssh.com,aes128-ctr Restart the system for the changes to take effect. Not_Reviewed Vuln_Num V-282525 Rule_ID SV-282525r1201367_rule Severity medium Rule_Title The TOSS 5 SSH server must be configured to use only Message Authentication Codes (MACs) employing FIPS 140-3-validated cryptographic hash algorithms. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. TOSS 5 incorporates systemwide crypto policies by default. The SSH configuration file has no effect on the ciphers, MACs, or algorithms unless specifically defined in the "/etc/sysconfig/sshd" file. The employed algorithms can be viewed in the "/etc/crypto-policies/back-ends/opensshserver.config" file. Check_Content Verify SSH server is configured to use only ciphers employing FIPS 140-3-approved algorithms using the following command: $ sudo grep -i macs /etc/crypto-policies/back-ends/openssh.config MACs hmac-sha2-256-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha2-256,hmac-sha1,umac-128@openssh.com,hmac-sha2-512 If the MACs entries in the "openssh.config" file have any hashes other than "hmac-sha2-256-etm@openssh.com", "hmac-sha2-256", "hmac-sha2-512-etm@openssh.com", "hmac-sha2-512"; the order differs from the example above; they are missing; or commented out, this is a finding. Fix_Text Configure the TOSS 5 SSH server to use only MACs employing FIPS 140-3-approved algorithms by updating the "/etc/crypto-policies/back-ends/openssh.config" file with the following line: MACs hmac-sha2-256-etm@openssh.com,hmac-sha1-etm@openssh.com,umac-128-etm@openssh.com,hmac-sha2-512-etm@openssh.com,hmac-sha2-256,hmac-sha1,umac-128@openssh.com,hmac-sha2-512 Restart the system for the changes to take effect. Not_Reviewed Vuln_Num V-282526 Rule_ID SV-282526r1201501_rule Severity high Rule_Title TOSS 5 must implement DOD or other applicable U.S. Government agency-approved TLS encryption in the GnuTLS package. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Transport Layer Security (TLS) encryption is a required security setting as a number of known vulnerabilities have been reported against Secure Sockets Layer (SSL) and earlier versions of TLS. Encryption of private information is essential to ensuring data confidentiality. If private information is not encrypted, it can be intercepted and easily read by an unauthorized party. SQL Server must use a minimum of FIPS 140-3-approved TLS version 1.2, and all non-FIPS-approved SSL and TLS versions must be disabled. NIST 800-53 specifies the preferred configurations for government systems. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. Satisfies: SRG-OS-000250-GPOS-00093, SRG-OS-000423-GPOS-00187 Check_Content Verify if GnuTLS uses defined DOD-approved TLS Crypto Policy using the following command: $ update-crypto-policies --show FIPS If the systemwide crypto policy is not set to "FIPS", this is a finding. Fix_Text Configure the TOSS 5 GnuTLS library to use only NIST-approved encryption by enabling FIPS mode using the following command: $ sudo fips-mode-setup --enable Restart the system for the changes to take effect. Not_Reviewed Vuln_Num V-282527 Rule_ID SV-282527r1200561_rule Severity medium Rule_Title TOSS 5 must implement DOD or other applicable U.S. Government agency -approved encryption in the OpenSSL package. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. The employed algorithms can be viewed in the "/etc/crypto-policies/back-ends/openssl.config" file. Check_Content Verify TOSS 5 OpenSSL library is configured to use only ciphers employing FIPS 140-3-approved algorithms using the following command: $ sudo grep -i opensslcnf.config /etc/pki/tls/openssl.cnf .include = /etc/crypto-policies/back-ends/opensslcnf.config If the "opensslcnf.config" is not defined in the "/etc/pki/tls/openssl.cnf" file, this is a finding. Fix_Text Configure the TOSS 5 OpenSSL library to use the system cryptographic policy. Edit the "/etc/pki/tls/openssl.cnf" and add or modify the following line: .include = /etc/crypto-policies/back-ends/opensslcnf.config Not_Reviewed Vuln_Num V-282528 Rule_ID SV-282528r1201630_rule Severity medium Rule_Title TOSS 5 must implement DOD or other applicable U.S. Government agency-approved TLS encryption in the OpenSSL package. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Remote access (e.g., RDP) is access to DOD nonpublic information systems by an authorized user (or an information system) communicating through an external, nonorganization-controlled network. Remote access methods include, for example, dial-up, broadband, and wireless. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/openssl.config file. Check_Content Verify TOSS 5 OpenSSL library is configured to use TLS 1.2 encryption or stronger with following command: $ grep -i minprotocol /etc/crypto-policies/back-ends/opensslcnf.config TLS.MinProtocol = TLSv1.2 DTLS.MinProtocol = DTLSv1.2 If the "TLS.MinProtocol" is set to anything older than "TLSv1.2" or the "DTLS.MinProtocol" is set to anything older than "DTLSv1.2", this is a finding. Fix_Text Configure the TOSS 5 OpenSSL library to use only DOD-approved TLS encryption by editing the following line in the "/etc/crypto-policies/back-ends/opensslcnf.config" file: TLS.MinProtocol = TLSv1.2 DTLS.MinProtocol = DTLSv1.2 Restart the system for the changes to take effect. Not_Reviewed Vuln_Num V-282529 Rule_ID SV-282529r1200567_rule Severity low Rule_Title TOSS 5 must allocate an audit_backlog_limit of sufficient size to capture processes that start prior to the audit daemon. Vuln_Discuss Without the capability to generate audit records, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. If auditing is enabled late in the startup process, the actions of some startup processes may not be audited. Some audit systems also maintain state information only available if auditing is enabled before a given process is created. Audit records can be generated from various components within the information system (e.g., module or policy filter). Allocating an audit_backlog_limit of sufficient size is critical in maintaining a stable boot process. With an insufficient limit allocated, the system is susceptible to boot failures and crashes. Satisfies: SRG-OS-000254-GPOS-00095, SRG-OS-000341-GPOS-00132 Check_Content Verify TOSS 5 allocates a sufficient audit_backlog_limit to capture processes that start prior to the audit daemon using the following command: $ sudo grubby --info=ALL | grep args | grep -v 'audit_backlog_limit=8192' If the command returns any outputs, and audit_backlog_limit is less than "8192", this is a finding. Fix_Text Configure TOSS 5 to allocate sufficient audit_backlog_limit to capture processes that start prior to the audit daemon using the following command: $ sudo grubby --update-kernel=ALL --args=audit_backlog_limit=8192 Not_Reviewed Vuln_Num V-282530 Rule_ID SV-282530r1200570_rule Severity medium Rule_Title TOSS 5 must produce audit records containing information to establish the identity of any individual or process associated with the event. Vuln_Discuss Without establishing what type of events occurred, the source of events, where events occurred, and the outcome of events, it would be difficult to establish, correlate, and investigate the events leading up to an outage or attack. Audit record content that may be necessary to satisfy this requirement includes, for example, time stamps, source and destination addresses, user/process identifiers, event descriptions, success/fail indications, filenames involved, and access control or flow control rules invoked. Enriched logging aids in making sense of who, what, and when events occur on a system. Without this, determining root cause of an event will be much more difficult. Check_Content Verify TOSS 5 audit system is configured to resolve audit information before writing to disk using the following command: $ sudo grep log_format /etc/audit/auditd.conf log_format = ENRICHED If the "log_format" option is not "ENRICHED", or the line is commented out, this is a finding. Fix_Text Edit the /etc/audit/auditd.conf file and add or update the "log_format" option: log_format = ENRICHED Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282531 Rule_ID SV-282531r1201577_rule Severity medium Rule_Title TOSS 5 audit tools must have a mode of 0755 or less permissive. Vuln_Discuss Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. TOSS 5 systems providing tools to interface with audit information leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user has, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Check_Content Verify the audit tools have a mode of "0755" or less using the following command: $ stat -c "%a %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules 755 /sbin/auditctl 755 /sbin/aureport 755 /sbin/ausearch 755 /sbin/autrace 755 /sbin/auditd 755 /sbin/rsyslogd 755 /sbin/augenrules If any of the audit tool files have a mode more permissive than "0755", this is a finding. Fix_Text Configure the audit tools to have a mode of "0755" using the following command: $ sudo chmod 0755 [audit_tool] Replace "[audit_tool]" with each audit tool that has a more permissive mode than "0755". Not_Reviewed Vuln_Num V-282532 Rule_ID SV-282532r1200576_rule Severity medium Rule_Title TOSS 5 audit tools must be owned by root. Vuln_Discuss Protecting audit information also includes identifying and protecting the tools used to view and manipulate log data. Therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. TOSS 5 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user has, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Check_Content Verify the audit tools are owned by "root" using the following command: $ sudo stat -c "%U %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules root /sbin/auditctl root /sbin/aureport root /sbin/ausearch root /sbin/autrace root /sbin/auditd root /sbin/rsyslogd root /sbin/augenrules If any audit tools do not have an owner of "root", this is a finding. Fix_Text Configure the audit tools to be owned by "root" using the following command: $ sudo chown root [audit_tool] Replace "[audit_tool]" with each audit tool not owned by "root". Not_Reviewed Vuln_Num V-282533 Rule_ID SV-282533r1201328_rule Severity medium Rule_Title TOSS 5 audit tools must be group-owned by root. Vuln_Discuss Protecting audit information includes identifying and protecting the tools used to view and manipulate log data; therefore, protecting audit tools is necessary to prevent unauthorized operation on audit information. TOSS 5 systems providing tools to interface with audit information will leverage user permissions and roles identifying the user accessing the tools, and the corresponding rights the user has, to make access decisions regarding the access to audit tools. Audit tools include, but are not limited to, vendor-provided and open source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. Check_Content Verify the audit tools are group owned by "root" using the following command: $ sudo stat -c "%G %n" /sbin/auditctl /sbin/aureport /sbin/ausearch /sbin/autrace /sbin/auditd /sbin/rsyslogd /sbin/augenrules root /sbin/auditctl root /sbin/aureport root /sbin/ausearch root /sbin/autrace root /sbin/auditd root /sbin/rsyslogd root /sbin/augenrules If any audit tools do not have a group owner of "root", this is a finding. Fix_Text Configure the audit tools to be group-owned by "root" using the following command: $ sudo chgrp root [audit_tool] Replace "[audit_tool]" with each audit tool not group-owned by "root". Not_Reviewed Vuln_Num V-282534 Rule_ID SV-282534r1200582_rule Severity medium Rule_Title TOSS 5 must use cryptographic mechanisms to protect the integrity of audit tools. Vuln_Discuss Protecting the integrity of the tools used for auditing purposes is a critical step toward ensuring the integrity of audit information. Audit information includes all information (e.g., audit records, audit settings, and audit reports) needed to successfully audit information system activity. Audit tools include, but are not limited to, vendor-provided and open-source audit tools needed to successfully view and manipulate audit information system activity and records. Audit tools include custom queries and report generators. It is not uncommon for attackers to replace the audit tools or inject code into the existing tools to provide the capability to hide or erase system activity from the audit logs. To address this risk, audit tools must be cryptographically signed to provide the capability to identify when the audit tools have been modified, manipulated, or replaced. An example is a checksum hash of the file or files. Satisfies: SRG-OS-000256-GPOS-00097, SRG-OS-000257-GPOS-00098, SRG-OS-000258-GPOS-00099, SRG-OS-000278-GPOS-00108 Check_Content Check that AIDE is properly configured to protect the integrity of the audit tools using the following command: $ sudo cat /etc/aide.conf | grep /usr/sbin/au /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 If AIDE is not installed, ask the system administrator (SA) how file integrity checks are performed on the system. If any of the audit tools listed above do not have a corresponding line, ask the SA to indicate what cryptographic mechanisms are being used to protect the integrity of the audit tools. If there is no evidence of integrity protection, this is a finding. Fix_Text Add or update the following lines to "/etc/aide.conf", to protect the integrity of the audit tools. /usr/sbin/auditctl p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/auditd p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/ausearch p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/aureport p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/autrace p+i+n+u+g+s+b+acl+xattrs+sha512 /usr/sbin/augenrules p+i+n+u+g+s+b+acl+xattrs+sha512 Not_Reviewed Vuln_Num V-282535 Rule_ID SV-282535r1200585_rule Severity medium Rule_Title TOSS 5 system commands must have mode 755 or less permissive. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the system commands contained in the following directories have mode "755" or less permissive with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/libexec /usr/local/bin /usr/local/sbin -perm /022 -exec ls -l {} \; If any system commands are found to be group-writable or world-writable, this is a finding. Fix_Text Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command with a mode more permissive than "755". $ sudo chmod 755 [FILE] Not_Reviewed Vuln_Num V-282536 Rule_ID SV-282536r1201579_rule Severity medium Rule_Title TOSS 5 library directories must have mode 755 or less permissive. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the systemwide shared library directories have mode "755" or less permissive with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 -perm /022 -type d -exec ls -l {} \; If any systemwide shared library directory is found to be group-writable or world-writable, this is a finding. Fix_Text Configure the systemwide shared library directories (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory with a mode more permissive than "755". $ sudo chmod 755 [DIRECTORY] Not_Reviewed Vuln_Num V-282537 Rule_ID SV-282537r1201581_rule Severity medium Rule_Title TOSS 5 library files must have mode 755 or less permissive. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the systemwide shared library files contained in the following directories have mode "755" or less permissive with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 -perm /022 -type f -exec ls -l {} \; If any systemwide shared library file is found to be group-writable or world-writable, this is a finding. Fix_Text Configure the library files to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file with a mode more permissive than "755". $ sudo chmod 755 [FILE] Not_Reviewed Vuln_Num V-282538 Rule_ID SV-282538r1200594_rule Severity medium Rule_Title TOSS 5 system commands must be owned by root. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the system commands contained in the following directories are owned by "root" with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/libexec /usr/local/bin /usr/local/sbin ! -user root -exec ls -l {} \; If any system commands are found to not be owned by root, this is a finding. Fix_Text Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command file not owned by "root". $ sudo chown root [FILE] Not_Reviewed Vuln_Num V-282539 Rule_ID SV-282539r1200597_rule Severity medium Rule_Title TOSS 5 system commands must be group-owned by root or a system account. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the system commands contained in the following directories are group-owned by "root", or a required system account, with the following command: $ sudo find -L /bin /sbin /usr/bin /usr/sbin /usr/local/bin /usr/local/sbin ! -group root -exec ls -l {} \; If any system commands are returned and is not group-owned by a required system account, and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the system commands to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any system command file not group-owned by "root" or a required system account. $ sudo chgrp root [FILE] Not_Reviewed Vuln_Num V-282540 Rule_ID SV-282540r1201318_rule Severity medium Rule_Title TOSS 5 library files must be owned by root. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the systemwide shared library files are owned by "root" with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 ! -user root -exec ls -l {} \; If any systemwide shared library file is not owned by root, this is a finding. Fix_Text Configure the systemwide shared library files (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file not owned by "root". $ sudo chown root [FILE] Not_Reviewed Vuln_Num V-282541 Rule_ID SV-282541r1201321_rule Severity medium Rule_Title TOSS 5 library files must be group-owned by root or a system account. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the systemwide shared library files are group-owned by "root" with the following command: $ sudo find -L /lib /lib64 /usr/lib /usr/lib64 ! -group root -exec ls -l {} \; If any systemwide shared library file is returned and is not group-owned by a required system account, and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the systemwide shared library files (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[FILE]" with any library file not group-owned by "root". $ sudo chgrp root [FILE] Not_Reviewed Vuln_Num V-282542 Rule_ID SV-282542r1201324_rule Severity medium Rule_Title TOSS 5 library directories must be owned by root. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the systemwide shared library directories are owned by "root" with the following command: $ sudo find /lib /lib64 /usr/lib /usr/lib64 ! -user root -type d -exec stat -c "%n %U" '{}' \; If any systemwide shared library directory is not owned by root, this is a finding. Fix_Text Configure the systemwide shared library directories within (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory not owned by "root". $ sudo chown root [DIRECTORY] Not_Reviewed Vuln_Num V-282543 Rule_ID SV-282543r1201327_rule Severity medium Rule_Title TOSS 5 library directories must be group-owned by root or a system account. Vuln_Discuss If TOSS 5 allowed any user to make changes to software libraries, then those changes might be implemented without undergoing the appropriate testing and approvals that are part of a robust change management process. This requirement applies to TOSS 5 with software libraries that are accessible and configurable, as in the case of interpreted languages. Software libraries also include privileged programs that execute with escalated privileges. Check_Content Verify the systemwide shared library directories are group-owned by "root" with the following command: $ sudo find /lib /lib64 /usr/lib /usr/lib64 ! -group root -type d -exec stat -c "%n %G" '{}' \; If any systemwide shared library directory is returned and is not group-owned by a required system account, and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the systemwide shared library directories (/lib, /lib64, /usr/lib and /usr/lib64) to be protected from unauthorized access. Run the following command, replacing "[DIRECTORY]" with any library directory not group-owned by "root". $ sudo chgrp root [DIRECTORY] Not_Reviewed Vuln_Num V-282544 Rule_ID SV-282544r1200612_rule Severity medium Rule_Title TOSS 5 must enforce password complexity by requiring at least one special character. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. Password complexity is one factor of several that determines how long it takes to crack a password. The more complex the password, the greater the number of possible combinations that must be tested before the password is compromised. TOSS 5 uses "pwquality" as a mechanism to enforce password complexity. Note that to require special characters without degrading the "minlen" value, the credit value must be expressed as a negative number in "/etc/security/pwquality.conf". Check_Content Verify TOSS 5 enforces password complexity by requiring at least one special character using the following command: $ sudo grep ocredit /etc/security/pwquality.conf /etc/security/pwquality.conf.d/*.conf ocredit = -1 If the value of "ocredit" is a positive number or is commented out, this is a finding. Fix_Text Configure TOSS 5 to enforce password complexity by requiring at least one special character be used by setting the "ocredit" option. Add the following line to "/etc/security/pwquality.conf" (or modify the line to have the required value): ocredit = -1 Not_Reviewed Vuln_Num V-282545 Rule_ID SV-282545r1200615_rule Severity medium Rule_Title The TOSS 5 systemd-journald service must be enabled. Vuln_Discuss In the event of a system failure, TOSS 5 must preserve any information necessary to determine cause of the failure and return to operations with the least disruption to system processes. Check_Content Verify "systemd-journald" is active on TOSS 5 using the following command: $ systemctl is-active systemd-journald active If the "systemd-journald" service is not active, this is a finding. Fix_Text Enable the "systemd-journald" service using the following command: $ sudo systemctl enable --now systemd-journald Not_Reviewed Vuln_Num V-282549 Rule_ID SV-282549r1200627_rule Severity medium Rule_Title TOSS 5 must securely compare internal information system clocks at least every 24 hours. Vuln_Discuss Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Depending on the infrastructure being used the "pool" directive may not be supported. Authoritative time sources include the United States Naval Observatory (USNO) time servers, a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). Satisfies: SRG-OS-000298-GPOS-00116, SRG-OS-000355-GPOS-00143, SRG-OS-000356-GPOS-00144, SRG-OS-000359-GPOS-00146 Check_Content Verify TOSS 5 is securely comparing internal information system clocks at least every 24 hours with an NTP server with the following commands: $ sudo grep maxpoll /etc/chrony.conf server 0.us.pool.ntp.mil iburst maxpoll 16 If the "maxpoll" option is set to a number greater than 16 or the line is commented out, this is a finding. Verify the "chrony.conf" file is configured to an authoritative DOD time source using the following command: $ sudo grep -i server /etc/chrony.conf server 0.us.pool.ntp.mil If the parameter "server" is not set or is not set to an authoritative DOD time source, this is a finding. Fix_Text Configure TOSS 5 to securely compare internal information system clocks at least every 24 hours with an NTP server by adding/modifying the following line in the /etc/chrony.conf file: server [ntp.server.name] iburst maxpoll 16 Not_Reviewed Vuln_Num V-282553 Rule_ID SV-282553r1200639_rule Severity medium Rule_Title TOSS 5 must enable kernel parameters to enforce discretionary access control on hardlinks. Vuln_Discuss By enabling the "fs.protected_hardlinks" kernel parameter, users can no longer create soft or hard links to files they do not own. Disallowing such hardlinks mitigates vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat(). Satisfies: SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125 Check_Content Verify TOSS 5 is configured to enable DAC on hardlinks using the following command: $ sudo sysctl fs.protected_hardlinks fs.protected_hardlinks = 1 If "fs.protected_hardlinks" is not set to "1" or is missing, this is a finding. Fix_Text Configure TOSS 5 to enable DAC on hardlinks with the following: Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: fs.protected_hardlinks = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282554 Rule_ID SV-282554r1201608_rule Severity medium Rule_Title TOSS 5 must enable kernel parameters to enforce discretionary access control (DAC) on symlinks. Vuln_Discuss By enabling the "fs.protected_symlinks" kernel parameter, symbolic links are permitted to be followed only when outside a sticky world-writable directory, or when the user identifier (UID) of the link and follower match, or when the directory owner matches the symlink's owner. Disallowing such symlinks helps mitigate vulnerabilities based on insecure file system accessed by privileged programs, avoiding an exploitation vector exploiting unsafe use of open() or creat(). Satisfies: SRG-OS-000312-GPOS-00123, SRG-OS-000324-GPOS-00125 Check_Content Verify TOSS 5 is configured to enable DAC on symlinks using the following command: $ sudo sysctl fs.protected_symlinks fs.protected_symlinks = 1 If "fs.protected_symlinks " is not set to "1" or is missing, this is a finding. Fix_Text Configure TOSS 5 to enable DAC on symlinks with the following: Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: fs.protected_symlinks = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282557 Rule_ID SV-282557r1200651_rule Severity high Rule_Title The systemd Ctrl-Alt-Delete burst key sequence in TOSS 5 must be disabled. Vuln_Discuss A locally logged-in user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed operating system environment, this can create the risk of short-term loss of systems availability due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken. Check_Content Verify TOSS 5 is configured to not reboot the system when Ctrl-Alt-Delete is pressed seven times within two seconds using the following command: $ sudo grep -iR CtrlAltDelBurstAction /etc/systemd/system* /etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction:CtrlAltDelBurstAction=none If "CtrlAltDelBurstAction" is not set to "none", is commented out, or is missing, this is a finding. Fix_Text Configure TOSS 5 to disable "CtrlAltDelBurstAction" by adding it to a drop file in a "/etc/systemd/system.conf.d/" configuration file: If no drop file exists, create one using the following command: $ sudo mkdir -p /etc/systemd/system.conf.d && sudo vi /etc/systemd/system.conf.d/55-CtrlAltDel-BurstAction Edit the file to contain the setting by adding the following text: CtrlAltDelBurstAction=none Reload the daemon for this change to take effect. $ sudo systemctl daemon-reload Not_Reviewed Vuln_Num V-282558 Rule_ID SV-282558r1200654_rule Severity high Rule_Title The x86 Ctrl-Alt-Delete key sequence must be disabled on TOSS 5. Vuln_Discuss A locally logged-in user who presses Ctrl-Alt-Delete when at the console can reboot the system. If accidentally pressed, as could happen in the case of a mixed operating system environment, this can create the risk of short-term loss of systems availability due to unintentional reboot. In a graphical user environment, risk of unintentional reboot from the Ctrl-Alt-Delete sequence is reduced because the user will be prompted before any action is taken. Check_Content Verify TOSS 5 is not configured to reboot the system when Ctrl-Alt-Delete is pressed using the following command: $ sudo systemctl status ctrl-alt-del.target ctrl-alt-del.target Loaded: masked (Reason: Unit ctrl-alt-del.target is masked.) Active: inactive (dead) If "ctrl-alt-del.target" is loaded and not masked, this is a finding. Fix_Text Configure TOSS 5 to disable "ctrl-alt-del.target" using the following command: $ sudo systemctl disable --now ctrl-alt-del.target $ sudo systemctl mask --now ctrl-alt-del.target Not_Reviewed Vuln_Num V-282559 Rule_ID SV-282559r1200657_rule Severity medium Rule_Title The TOSS 5 debug-shell systemd service must be disabled. Vuln_Discuss The debug-shell requires no authentication and provides root privileges to anyone who has physical access to the machine. While this feature is disabled by default, masking it adds an additional layer of assurance that it will not be enabled via a dependency in systemd. This also prevents attackers with physical access from trivially bypassing security on the machine through valid troubleshooting configurations and gaining root access when the system is rebooted. Check_Content Verify TOSS 5 is configured to mask the "debug-shell systemd" service using the following command: $ sudo systemctl status debug-shell.service debug-shell.service Loaded: masked (Reason: Unit debug-shell.service is masked.) Active: inactive (dead) If the "debug-shell.service" is loaded and not masked, this is a finding. Fix_Text Configure TOSS 5 to mask the "debug-shell systemd" service using the following command: $ sudo systemctl disable --now debug-shell.service $ sudo systemctl mask --now debug-shell.service Not_Reviewed Vuln_Num V-282560 Rule_ID SV-282560r1200660_rule Severity medium Rule_Title TOSS 5 must have the sudo package installed. Vuln_Discuss "sudo" is a program designed to allow a system administrator to give limited root privileges to users and log root activity. The basic philosophy is to give as few privileges as possible but still allow system users to get their work done. Check_Content Verify the TOSS 5 "sudo" package is installed using the following command: $ sudo dnf list --installed sudo Example output: sudo.x86_64 1.9.5p2-7.el9 If the "sudo" package is not installed, this is a finding. Fix_Text The "sudo" package can be installed using the following command: $ sudo dnf install sudo Not_Reviewed Vuln_Num V-282561 Rule_ID SV-282561r1200663_rule Severity medium Rule_Title TOSS 5 must audit uses of the execve system call. Vuln_Discuss Misuse of privileged functions, either intentionally or unintentionally by authorized users, or by unauthorized external entities that have compromised information system accounts, is a serious and ongoing concern and can have significant adverse impacts on organizations. Auditing the use of privileged functions is one way to detect such misuse and identify the risk from insider threats and the advanced persistent threat. Satisfies: SRG-OS-000326-GPOS-00126, SRG-OS-000327-GPOS-00127 Check_Content Verify TOSS 5 is configured to audit the execution of the "execve" system call using the following command: $ sudo auditctl -l | grep execve -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k execpriv If the command does not return all lines, or the lines are commented out, this is a finding. Fix_Text Configure TOSS 5 to audit the execution of the "execve" system call. Add or update the following file system rules to "/etc/audit/rules.d/audit.rules": -a always,exit -F arch=b32 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C uid!=euid -F euid=0 -k execpriv -a always,exit -F arch=b32 -S execve -C gid!=egid -F egid=0 -k execpriv -a always,exit -F arch=b64 -S execve -C gid!=egid -F egid=0 -k execpriv Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282562 Rule_ID SV-282562r1201623_rule Severity medium Rule_Title TOSS 5 must allocate audit record storage capacity to store at least one week's worth of audit records. Vuln_Discuss To ensure TOSS 5 systems have a sufficient storage capacity in which to write the audit logs, TOSS 5 needs to be able to allocate audit record storage capacity. The task of allocating audit record storage capacity is usually performed during initial installation of TOSS 5. Check_Content Verify TOSS 5 allocates audit record storage capacity to store at least one week of audit records when audit records are not immediately sent to a central audit record storage facility. If the system is configured to immediately off-load audit records to an external system, this requirement is not applicable. Note: The partition size needed to capture a week of audit records is based on the activity level of the system and the total storage capacity available. Typically, 10GB of storage space for audit records should be sufficient. Determine which partition the audit records are being written to using the following command: $ sudo grep log_file /etc/audit/auditd.conf log_file = /var/log/audit/audit.log Check the size of the partition that audit records are written to with the following command to verify whether it is large enough: # df -h /var/log/audit/ /dev/sda2 24G 10.4G 13.6G 43% /var/log/audit If the audit record partition is not allocated for sufficient storage capacity, this is a finding. Fix_Text Allocate enough storage capacity for at least one week of audit records when audit records are not immediately sent to a central audit record storage facility. If audit records are stored on a partition made specifically for audit records, resize the partition with sufficient space to contain one week of audit records. If audit records are not stored on a partition made specifically for audit records, a new partition with sufficient space will need be to be created. Not_Reviewed Vuln_Num V-282563 Rule_ID SV-282563r1200669_rule Severity medium Rule_Title TOSS 5 must be configured to off-load audit records onto a different system from the system being audited via syslog. Vuln_Discuss The auditd service does not include the ability to send audit records to a centralized server for management directly. However, it can use a plug-in for an audit event multiplexor (audispd) to pass audit records to the local syslog server. Check_Content Verify TOSS 5 is configured use the "audisp-remote" syslog service using the following command: $ sudo grep active /etc/audit/plugins.d/syslog.conf active = yes If the "active" keyword does not have a value of "yes", the line is commented out, or the line is missing, this is a finding. Fix_Text Edit the "/etc/audit/plugins.d/syslog.conf" file and add or update the "active" option: active = yes Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282564 Rule_ID SV-282564r1201619_rule Severity medium Rule_Title TOSS 5 must authenticate the remote logging server for off-loading audit logs via rsyslog. Vuln_Discuss Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. TOSS 5 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS, and DTLS protocols) creates a method to securely encrypt and off-load auditing. Rsyslog-supported authentication modes include: anon - anonymous authentication x509/fingerprint - certificate fingerprint authentication x509/certvalid - certificate validation only x509/name - certificate validation and subject name authentication Check_Content Verify TOSS 5 authenticates the remote logging server for off-loading audit logs using the following command: $ sudo grep -i '$ActionSendStreamDriverAuthMode' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$ActionSendStreamDriverAuthMode x509/name If the value of the "$ActionSendStreamDriverAuthMode" option is not set to "x509/name" or the line is commented out, ask the system administrator (SA) to indicate how the audit logs are off-loaded to a different system or media. If there is no evidence that the transfer of the audit logs being off-loaded to another system or media is encrypted, this is a finding. Fix_Text Configure TOSS 5 to authenticate the remote logging server for off-loading audit logs by setting the following option in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $ActionSendStreamDriverAuthMode x509/name Not_Reviewed Vuln_Num V-282565 Rule_ID SV-282565r1201620_rule Severity medium Rule_Title TOSS 5 must encrypt the transfer of audit records off-loaded onto a different system or media from the system being audited via rsyslog. Vuln_Discuss Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. TOSS 5 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS, and DTLS protocols) creates a method to securely encrypt and off-load auditing. Rsyslog-supported authentication modes include: anon - anonymous authentication x509/fingerprint - certificate fingerprint authentication x509/certvalid - certificate validation only x509/name - certificate validation and subject name authentication Check_Content Verify TOSS 5 encrypts audit records off-loaded onto a different system or media from the system being audited via rsyslog using the following command: $ sudo grep -i '$ActionSendStreamDriverMode' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$ActionSendStreamDriverMode 1 If the value of the "$ActionSendStreamDriverMode" option is not set to "1" or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to encrypt off-loaded audit records via rsyslog by setting the following options in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $ActionSendStreamDriverMode 1 Not_Reviewed Vuln_Num V-282566 Rule_ID SV-282566r1200678_rule Severity medium Rule_Title TOSS 5 must encrypt, via the gtls driver, the transfer of audit records off-loaded onto a different system or media from the system being audited via rsyslog. Vuln_Discuss Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. TOSS 5 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS, and DTLS protocols) creates a method to securely encrypt and off-load auditing. Check_Content Verify TOSS 5 uses the gtls driver to encrypt audit records off-loaded onto a different system or media from the system being audited using the following command: $ sudo grep -i '$DefaultNetstreamDriver' /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:$DefaultNetstreamDriver gtls If the value of the "$DefaultNetstreamDriver" option is not set to "gtls" or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to use the gtls driver to encrypt off-loaded audit records by setting the following options in "/etc/rsyslog.conf" or "/etc/rsyslog.d/[customfile].conf": $DefaultNetstreamDriver gtls Not_Reviewed Vuln_Num V-282567 Rule_ID SV-282567r1200681_rule Severity medium Rule_Title TOSS 5 must take appropriate action when the internal event queue is full. Vuln_Discuss The audit system should have an action setup in the event the internal event queue becomes full so that no data is lost. Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Off-loading is a common process in information systems with limited audit storage capacity. Check_Content Verify TOSS 5 audit system is configured to take an appropriate action when the internal event queue is full: $ sudo grep -i overflow_action /etc/audit/auditd.conf overflow_action = syslog If the value of the "overflow_action" option is not set to "syslog", "single", "halt" or the line is commented out, ask the system administrator (SA) to indicate how the audit logs are off-loaded to a different system or media. If there is no evidence that the transfer of the audit logs being off-loaded to another system or media takes appropriate action if the internal event queue becomes full, this is a finding. Fix_Text Edit the "/etc/audit/auditd.conf" file and add or update the "overflow_action" option: overflow_action = syslog Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282568 Rule_ID SV-282568r1200684_rule Severity medium Rule_Title TOSS 5 audispd-plugins package must be installed. Vuln_Discuss "audispd-plugins" provides plugins for the real-time interface to the audit subsystem, "audispd". These plugins can relay events to remote machines or analyze events for suspicious behavior. Check_Content Verify TOSS 5 has the "audispd-plugins" package for installed using the following command: $ sudo dnf list --installed audispd-plugins Example output: audispd-plugins.x86_64 3.0.7-101.el9_0.2 If the "audispd-plugins" package is not installed, this is a finding. Fix_Text Install the "audispd-plugins" package using the following command: $ sudo dnf install audispd-plugins Not_Reviewed Vuln_Num V-282569 Rule_ID SV-282569r1200687_rule Severity medium Rule_Title TOSS 5 must act when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity. Vuln_Discuss If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion. Check_Content Verify TOSS 5 takes action when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity using the following command: $ sudo grep -w space_left /etc/audit/auditd.conf space_left = 25% If the value of the "space_left" keyword is not set to 25 percent of the storage volume allocated to audit logs, or if the line is commented out, ask the system administrator (SA) to indicate how the system is providing real-time alerts to the SA and information system security officer (ISSO). If the "space_left" value is not configured to the correct value, this is a finding. Fix_Text Configure TOSS 5 to initiate an action to notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the /etc/audit/auditd.conf file. space_left = 25% Not_Reviewed Vuln_Num V-282570 Rule_ID SV-282570r1200690_rule Severity medium Rule_Title TOSS 5 must notify the system administrator (SA) and information system security officer (ISSO) (at a minimum) when allocated audit record storage volume 75 percent utilization. Vuln_Discuss If security personnel are not notified immediately when storage volume reaches 75 percent utilization, they are unable to plan for audit record storage capacity expansion. Check_Content Verify TOSS 5 notifies the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity using the following command: $ sudo grep -w space_left_action /etc/audit/auditd.conf space_left_action = email If the value of the "space_left_action" is not set to "email", or if the line is commented out, ask the SA to indicate how the system is providing real-time alerts to the SA and ISSO. If there is no evidence that real-time alerts are configured on the system, this is a finding. Fix_Text Configure TOSS 5 to initiate an action to notify the SA and ISSO (at a minimum) when allocated audit record storage volume reaches 75 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the /etc/audit/auditd.conf file. space_left_action = email Not_Reviewed Vuln_Num V-282571 Rule_ID SV-282571r1200693_rule Severity medium Rule_Title TOSS 5 must act when allocated audit record storage volume reaches 95 percent of the audit record storage capacity. Vuln_Discuss If action is not taken when storage volume reaches 95 percent utilization, the auditing system may fail when the storage volume reaches capacity. Check_Content Verify TOSS 5 takes action when allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity using the following command: $ sudo grep -w admin_space_left /etc/audit/auditd.conf admin_space_left = 5% If the value of the "admin_space_left" keyword is not set to 5 percent of the storage volume allocated to audit logs, or if the line is commented out, ask the system administrator (SA) to indicate how the system is taking action if the allocated storage is about to reach capacity. If the "space_left" value is not configured to the correct value, this is a finding. Fix_Text Configure TOSS 5 to initiate an action when allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity by adding/modifying the following line in the "/etc/audit/auditd.conf" file. admin_space_left = 5% Not_Reviewed Vuln_Num V-282572 Rule_ID SV-282572r1200696_rule Severity medium Rule_Title TOSS 5 must act when allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity. Vuln_Discuss If action is not taken when storage volume reaches 95 percent utilization, the auditing system may fail when the storage volume reaches capacity. Check_Content Verify TOSS 5 is configured to take action in the event of allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity using the following command: $ sudo grep admin_space_left_action /etc/audit/auditd.conf admin_space_left_action = single If the value of the "admin_space_left_action" is not set to "single", or if the line is commented out, ask the system administrator (SA) to indicate how the system is providing real-time alerts to the SA and information system security officer (ISSO). If there is no evidence that real-time alerts are configured on the system, this is a finding. Fix_Text Configure "auditd" service to act in the event of allocated audit record storage volume reaches 95 percent of the repository maximum audit record storage capacity. Edit the following line in "/etc/audit/auditd.conf" to ensure that the system is forced into single user mode in the event the audit record storage volume is about to reach maximum capacity: admin_space_left_action = single Restart the audit daemon changes to take effect. Not_Reviewed Vuln_Num V-282574 Rule_ID SV-282574r1200702_rule Severity medium Rule_Title TOSS 5 must have the chrony package installed. Vuln_Discuss Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Check_Content Verify TOSS 5 has the "chrony" package installed using the following command: $ sudo dnf list --installed chrony Example output: chrony.x86_64 4.1-3.el9 If the "chrony" package is not installed, this is a finding. Fix_Text The "chrony" package can be installed using the following command: $ sudo dnf install chrony Not_Reviewed Vuln_Num V-282575 Rule_ID SV-282575r1200705_rule Severity medium Rule_Title TOSS 5 chronyd service must be enabled. Vuln_Discuss Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Check_Content Verify the "chronyd" service is active using the following command: $ systemctl is-active chronyd active If the "chronyd" service is not active, this is a finding. Fix_Text Enable the "chronyd" service using the following command: $ sudo systemctl enable --now chronyd Not_Reviewed Vuln_Num V-282578 Rule_ID SV-282578r1200714_rule Severity medium Rule_Title TOSS 5 must have the s-nail package installed. Vuln_Discuss The "s-nail" package provides the mail command required to allow sending email notifications of unauthorized configuration changes to designated personnel. Check_Content Verify TOSS 5 is configured to allow sending email notifications. Note: The "s-nail" package provides the "mail" command that is used to send email messages. Verify the "s-nail" package is installed on the system: $ sudo dnf list --installed s-nail s-nail.x86_64 14.9.22-6.el9 If "s-nail" package is not installed, this is a finding. Fix_Text The "s-nail" package can be installed using the following command: $ sudo dnf install s-nail Not_Reviewed Vuln_Num V-282579 Rule_ID SV-282579r1201582_rule Severity medium Rule_Title TOSS 5 must have the Advanced Intrusion Detection Environment (AIDE) package installed. Vuln_Discuss Without verifying the security functions, security functions may not operate correctly, and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. Satisfies: SRG-OS-000363-GPOS-00150, SRG-OS-000445-GPOS-00199 Check_Content Verify TOSS 5 has the AIDE package installed using the following command: $ sudo dnf list --installed aide Example output: aide.x86_64 0.16.100.el9 If AIDE is not installed, ask the system administrator (SA) how file integrity checks are performed on the system. If there is no application installed to perform integrity checks, this is a finding. If AIDE is installed, check if it has been initialized using the following command: $ sudo /usr/sbin/aide --check If the output is "Couldn't open file /var/lib/aide/aide.db.gz for reading", this is a finding. Fix_Text Install AIDE, initialize it, and perform a manual check. Install AIDE: $ sudo dnf install aide Initialize AIDE: $ sudo /usr/sbin/aide --init Example output: Start timestamp: 2023-06-05 10:09:04 -0600 (AIDE 0.16) AIDE initialized database at /var/lib/aide/aide.db.new.gz Number of entries: 86833 --------------------------------------------------- The attributes of the (uncompressed) database(s): --------------------------------------------------- /var/lib/aide/aide.db.new.gz MD5 : coZUtPHhoFoeD7+k54fUvQ== SHA1 : DVpOEMWJwo0uPgrKZAygIUgSxeM= SHA256 : EQiZH0XNEk001tcDmJa+5STFEjDb4MPE TGdBJ/uvZKc= SHA512 : 86KUqw++PZhoPK0SZvT3zuFq9yu9nnPP toei0nENVELJ1LPurjoMlRig6q69VR8l +44EwO9eYyy9nnbzQsfG1g== End timestamp: 2023-06-05 10:09:57 -0600 (run time: 0m 53s) The new database must be renamed to be read by AIDE: $ sudo mv /var/lib/aide/aide.db.new.gz /var/lib/aide/aide.db.gz Perform a manual check: $ sudo /usr/sbin/aide --check Example output: 2023-06-05 10:16:08 -0600 (AIDE 0.16) AIDE found NO differences between database and filesystem. Looks okay!! Not_Reviewed Vuln_Num V-282580 Rule_ID SV-282580r1201642_rule Severity medium Rule_Title TOSS 5 must routinely check the baseline configuration for unauthorized changes and notify the system administrator (SA) when anomalies in the operation of any security functions are discovered. Vuln_Discuss Unauthorized changes to the baseline configuration could make the system vulnerable to various attacks or allow unauthorized access to the operating system. Changes to operating system configurations can have unintended side effects, some of which may be relevant to security. Detecting such changes and providing an automated response can help avoid unintended, negative consequences that could ultimately affect the security state of the operating system. The operating system's information management officer (IMO)/information system security officer (ISSO) and SAs must be notified via email and/or monitoring system trap when there is an unauthorized modification of a configuration item. Notifications provided by information systems include messages to local computer consoles, and/or hardware indications, such as lights. This capability must take into account operational requirements for availability for selecting an appropriate response. The organization may choose to shut down or restart the information system upon security function anomaly detection. Satisfies: SRG-OS-000363-GPOS-00150, SRG-OS-000445-GPOS-00199, SRG-OS-000205-GPOS-00083, SRG-OS-000447-GPOS-00201 Check_Content Verify TOSS 5 routinely executes a file integrity scan for changes to the system baseline. The command used in the example will use a daily occurrence. Check the cron directories for scripts controlling the execution and notification of results of the file integrity application. For example, if AIDE is installed on the system, use the following commands: $ ls -al /etc/cron.* | grep aide -rwxr-xr-x 1 root root 29 Nov 22 2015 aide $ grep aide /etc/crontab /var/spool/cron/root /etc/crontab: 30 04 * * * root usr/sbin/aide /var/spool/cron/root: 30 04 * * * root usr/sbin/aide $ sudo more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily aide integrity check run" root@sysname.mil If the file integrity application does not exist, or a script file controlling the execution of the file integrity application does not exist, or the file integrity application does not notify designated personnel of changes, this is a finding. Fix_Text Configure the file integrity tool to run automatically on the system at least weekly and to notify designated personnel if baseline configurations are changed in an unauthorized manner. The AIDE tool can be configured to email designated personnel with the use of the cron system. The following example output is generic. It will set cron to run AIDE daily and to send email at the completion of the analysis: $ sudo more /etc/cron.daily/aide #!/bin/bash /usr/sbin/aide --check | /bin/mail -s "$HOSTNAME - Daily aide integrity check run" root@sysname.mil Not_Reviewed Vuln_Num V-282581 Rule_ID SV-282581r1200723_rule Severity medium Rule_Title TOSS 5 SSH daemon must not allow Kerberos authentication. Vuln_Discuss Kerberos authentication for SSH is often implemented using Generic Security Service Application Program Interface (GSSAPI). If Kerberos is enabled through SSH, the SSH daemon provides a means of access to the system's Kerberos implementation. Vulnerabilities in the system's Kerberos implementations may be subject to exploitation. Check_Content Verify the SSH daemon does not allow Kerberos authentication using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*kerberosauthentication' KerberosAuthentication no If the value is returned as "yes", the returned line is commented out, no output is returned, and the use of Kerberos authentication has not been documented with the information system security officer (ISSO), this is a finding. Fix_Text Configure the SSH daemon to not allow Kerberos authentication. Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "no": KerberosAuthentication no Restart the SSH service for changes to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282582 Rule_ID SV-282582r1200726_rule Severity high Rule_Title TOSS 5 must ensure cryptographic verification of vendor software packages. Vuln_Discuss Cryptographic verification of vendor software packages ensures that all software packages are obtained from a valid source and protects against spoofing that could lead to installation of malware on the system. Red Hat cryptographically signs all software packages, which includes updates, with a GPG key to verify that they are valid. Check_Content Confirm Red Hat package-signing keys are installed on the system and verify their fingerprints match vendor values. Note: For TOSS 5 software packages, Red Hat uses GPG keys labeled "release key 2" and "auxiliary key 3". The keys are defined in key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" by default. List Red Hat GPG keys installed on the system: $ sudo rpm -q --queryformat "%{SUMMARY}\n" gpg-pubkey | grep -i "red hat" Red Hat, Inc. (release key 2) <security@redhat.com> public key Red Hat, Inc. (auxiliary key 3) <security@redhat.com> public key If Red Hat GPG keys "release key 2" and "auxiliary key 3" are not installed, this is a finding. List key fingerprints of installed Red Hat GPG keys: $ sudo gpg -q --keyid-format short --with-fingerprint /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release If key file "/etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release" is missing, this is a finding. Example output: pub rsa4096/FD431D51 2009-10-22 [SC] Key fingerprint = 567E 347A D004 4ADE 55BA 8A5F 199E 2F91 FD43 1D51 uid Red Hat, Inc. (release key 2) <security@redhat.com> pub rsa4096/5A6340B3 2022-03-09 [SC] Key fingerprint = 7E46 2425 8C40 6535 D56D 6F13 5054 E4A4 5A63 40B3 uid Red Hat, Inc. (auxiliary key 3) <security@redhat.com> Compare key fingerprints of installed Red Hat GPG keys with fingerprints listed for TOSS 5 on Red Hat "Product Signing Keys" webpage at https://access.redhat.com/security/team/key. If key fingerprints do not match, this is a finding. Fix_Text Install Red Hat package-signing keys on the system and verify their fingerprints match vendor values. Insert TOSS 5 installation disc or attach TOSS 5 installation image to the system. Mount the disc or image to make the contents accessible inside the system. Assuming the mounted location is "/media/cdrom", use the following command to copy Red Hat GPG key file onto the system: $ sudo cp /media/cdrom/RPM-GPG-KEY-redhat-release /etc/pki/rpm-gpg/ Import Red Hat GPG keys from key file into system keyring: $ sudo rpm --import /etc/pki/rpm-gpg/RPM-GPG-KEY-redhat-release Using the steps listed in the Check, confirm the newly imported keys show as installed on the system and verify their fingerprints match vendor values. Not_Reviewed Vuln_Num V-282583 Rule_ID SV-282583r1200729_rule Severity high Rule_Title TOSS 5 must check the GPG signature of software packages originating from external software repositories before installation. Vuln_Discuss Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. Check_Content Verify dnf always checks the GPG signature of software packages originating from external software repositories before installation: $ grep gpgcheck /etc/dnf/dnf.conf gpgcheck=1 If "gpgcheck" is not set to "1", or if the option is missing or commented out, ask the system administrator how the GPG signatures of software packages are verified. If there is no process to verify GPG signatures that is approved by the organization, this is a finding. Fix_Text Configure dnf to always check the GPG signature of software packages originating from external software repositories before installation. Add or update the following line in the [main] section of the /etc/dnf/dnf.conf file: gpgcheck=1 Not_Reviewed Vuln_Num V-282584 Rule_ID SV-282584r1200732_rule Severity high Rule_Title TOSS 5 must check the GPG signature of locally installed software packages before installation. Vuln_Discuss Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. Check_Content Verify dnf always checks the GPG signature of locally installed software packages before installation: $ grep localpkg_gpgcheck /etc/dnf/dnf.conf localpkg_gpgcheck=1 If "localpkg_gpgcheck" is not set to "1", or if the option is missing or commented out, ask the system administrator how the GPG signatures of local software packages are verified. If there is no process to verify GPG signatures that is approved by the organization, this is a finding. Fix_Text Configure dnf to always check the GPG signature of local software packages before installation. Add or update the following line in the [main] section of the /etc/dnf/dnf.conf : localpkg_gpgcheck=1 Not_Reviewed Vuln_Num V-282585 Rule_ID SV-282585r1200735_rule Severity high Rule_Title TOSS 5 must have GPG signature verification enabled for all software repositories. Vuln_Discuss Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. All software packages must be signed with a cryptographic key recognized and approved by the organization. Verifying the authenticity of software prior to installation validates the integrity of the software package received from a vendor. This verifies the software has not been tampered with and that it has been provided by a trusted vendor. Check_Content Verify all software repositories defined in "/etc/yum.repos.d/" have been configured with "gpgcheck" enabled: $ grep gpgcheck /etc/yum.repos.d/*.repo | more gpgcheck = 1 If "gpgcheck" is not set to "1" for all returned lines, this is a finding. Fix_Text Configure all software repositories defined in "/etc/yum.repos.d/" to have "gpgcheck" enabled: $ sudo sed -i 's/gpgcheck\s*=.*/gpgcheck=1/g' /etc/yum.repos.d/* Not_Reviewed Vuln_Num V-282586 Rule_ID SV-282586r1200738_rule Severity medium Rule_Title TOSS 5 subscription-manager package must be installed. Vuln_Discuss The Subscription Manager application manages software subscriptions and software repositories for installed software products on the local system. It communicates with backend servers, such as the Red Hat Customer Portal or an on-premise instance of Subscription Asset Manager, to register the local system and grant access to software resources determined by the subscription entitlement. Check_Content Verify the TOSS 5 "subscription-manager" package is installed using the following command: $ sudo dnf list --installed subscription-manager Example output: subscription-manager.x86_64 1.29.26-3.el9_0 If the "subscription-manager" package is not installed, this is a finding. Fix_Text Install the "subscription-manager" package using the following command: $ sudo dnf install subscription-manager Not_Reviewed Vuln_Num V-282587 Rule_ID SV-282587r1200741_rule Severity medium Rule_Title TOSS 5 must mount /var/tmp with the nosuid option. Vuln_Discuss The "nosuid" mount option causes the system to not execute "setuid" and "setgid" files with owner privileges. This option must be used for mounting any file system not containing approved "setuid" and "setguid" files. Executing files from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. Check_Content Verify "/var/tmp" is mounted with the "nosuid" option: $ mount | grep /var/tmp /dev/mapper/rhel-var-tmp on /var/tmp type xfs (rw,nodev,nosuid,noexec,seclabel) If the "/var/tmp" file system is mounted without the "nosuid" option, this is a finding. Fix_Text Modify "/etc/fstab" to use the "nosuid" option on the "/var/tmp" directory. Not_Reviewed Vuln_Num V-282588 Rule_ID SV-282588r1200744_rule Severity medium Rule_Title TOSS 5 must disable the graphical user interface autorun function unless required. Vuln_Discuss Allowing autorun commands to execute may introduce malicious code to a system. Configuring this setting prevents users from executing autorun commands. Check_Content Verify TOSS 5 disables the graphical user interface autorun function using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface—the GNOME desktop environment. If the system does not have a graphical user interface installed, this requirement is not applicable. $ gsettings get org.gnome.desktop.media-handling autorun-never true If "autorun-never" is set to "false" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the GNOME desktop to disable the autorun function on removable media. The dconf settings can be edited in the /etc/dconf/db/* location. Update the [org/gnome/desktop/media-handling] section of the "/etc/dconf/db/local.d/00-security-settings" database file and add or update the following lines: [org/gnome/desktop/media-handling] autorun-never=true Update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282589 Rule_ID SV-282589r1200747_rule Severity medium Rule_Title TOSS 5 fapolicy module must be installed. Vuln_Discuss The organization must identify authorized software programs and permit execution of authorized software. The process used to identify software programs that are authorized to execute on organizational information systems is commonly referred to as allowlisting. Using an allowlist provides a configuration management method for allowing the execution of only authorized software. Using only authorized software decreases risk by limiting the number of potential vulnerabilities. Verification of allowlisted software occurs prior to execution or at system startup. User home directories/folders may contain information of a sensitive nature. Nonprivileged users should coordinate any sharing of information with a system administrator (SA) through shared resources. TOSS 5 ships with many optional packages. One such package is a file access policy daemon called "fapolicyd". "fapolicyd" is a userspace daemon that determines access rights to files based on attributes of the process and file. It can be used to either blocklist or allowlist processes or file access. Proceed with caution when using this daemon. Improper configuration may render the system nonfunctional. The "fapolicyd" API is not namespace-aware and can cause issues when launching or running containers. Satisfies: SRG-OS-000368-GPOS-00154, SRG-OS-000370-GPOS-00155 Check_Content Verify the TOSS 5 "fapolicyd" package is installed using the following command: $ sudo dnf list --installed fapolicyd Example output: fapolicyd.x86_64 1.1-103.el9_0 If the "fapolicyd" package is not installed, this is a finding. Fix_Text Install the "fapolicyd" package using the following command: $ sudo dnf install fapolicyd Not_Reviewed Vuln_Num V-282590 Rule_ID SV-282590r1200750_rule Severity medium Rule_Title TOSS 5 must use the invoking user's password for privilege escalation when using sudo. Vuln_Discuss If the "rootpw", "targetpw", or "runaspw" flags are defined and not disabled, by default the operating system will prompt the invoking user for the "root" user password. Satisfies: SRG-OS-000373-GPOS-00156, SRG-OS-000373-GPOS-00157, SRG-OS-000373-GPOS-00158 Check_Content Verify the sudoers security policy is configured to use the invoking user's password for privilege escalation using the following command: $ sudo egrep -ir '(!rootpw|!targetpw|!runaspw)' /etc/sudoers /etc/sudoers.d/* | grep -v '#' /etc/sudoers:Defaults !targetpw /etc/sudoers:Defaults !rootpw /etc/sudoers:Defaults !runaspw If no results are returned, this is a finding. If results are returned from more than one file location, this is a finding. If "Defaults !targetpw" is not defined, this is a finding. If "Defaults !rootpw" is not defined, this is a finding. If "Defaults !runaspw" is not defined, this is a finding. Fix_Text Define the following in the Defaults section of the "/etc/sudoers" file or a single configuration file in the "/etc/sudoers.d/" directory: Defaults !targetpw Defaults !rootpw Defaults !runaspw Not_Reviewed Vuln_Num V-282591 Rule_ID SV-282591r1200753_rule Severity medium Rule_Title TOSS 5 must have the pcsc-lite package installed. Vuln_Discuss The "pcsc-lite" package must be installed so it is available for multifactor authentication using smart cards. Check_Content Verify TOSS 5 has the "pcsc-lite" package installed using the following command: $ sudo dnf list --installed pcsc-lite Example output: pcsc-lite.x86_64 1.9.4-1.el9 If the "pcsc-lite" package is not installed, this is a finding. Fix_Text Install the "pcsc-lite" package using the following command: $ sudo dnf install pcsc-lite Not_Reviewed Vuln_Num V-282592 Rule_ID SV-282592r1200756_rule Severity medium Rule_Title TOSS 5 must have the opensc package installed. Vuln_Discuss The use of PIV credentials facilitates standardization and reduces the risk of unauthorized access. The DOD has mandated the use of the common access card (CAC) to support identity management and personal authentication for systems covered under Homeland Security Presidential Directive (HSPD) 12, as well as making the CAC a primary component of layered protection for national security systems. Satisfies: SRG-OS-000375-GPOS-00160, SRG-OS-000376-GPOS-00161, SRG-OS-000377-GPOS-00162 Check_Content Verify TOSS 5 has the "opensc" package installed using the following command: $ sudo dnf list --installed opensc Example output: opensc.x86_64 0.22.0-2.el9 If the "opensc" package is not installed, this is a finding. Fix_Text Install the "opensc" package using the following command: $ sudo dnf install opensc Not_Reviewed Vuln_Num V-282593 Rule_ID SV-282593r1200759_rule Severity medium Rule_Title TOSS 5 must have the USBGuard package installed. Vuln_Discuss The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the "usbguard-rules.conf" file. The policy and the authorization state of USB devices can be modified during runtime using the usbguard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices. Satisfies: SRG-OS-000378-GPOS-00163, SRG-OS-000690-GPOS-00140 Check_Content Verify USBGuard is installed on the operating system using the following command: $ sudo dnf list installed usbguard usbguard.x86_64 1.0.0-10.el9_1.2 @rhel-9-for-x86_64-appstream-rpms If the USBGuard package is not installed, ask the SA to indicate how unauthorized peripherals are blocked. If there is no evidence that unauthorized peripherals are blocked before establishing a connection, this is a finding. Fix_Text Install the usbguard package using the following command: $ sudo dnf install usbguard Not_Reviewed Vuln_Num V-282594 Rule_ID SV-282594r1200762_rule Severity medium Rule_Title TOSS 5 must have the USBGuard package enabled. Vuln_Discuss The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the usbguard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices. Satisfies: SRG-OS-000378-GPOS-00163, SRG-OS-000690-GPOS-00140 Check_Content Verify TOSS 5 has USBGuard enabled using the following command: $ systemctl is-active usbguard active If usbguard is not active, ask the SA to indicate how unauthorized peripherals are blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding. Fix_Text Enable the USBGuard service using the following command: $ sudo systemctl enable --now usbguard Not_Reviewed Vuln_Num V-282595 Rule_ID SV-282595r1200765_rule Severity medium Rule_Title TOSS 5 must block unauthorized peripherals before establishing a connection. Vuln_Discuss The USBguard-daemon is the main component of the USBGuard software framework. It runs as a service in the background and enforces the USB device authorization policy for all USB devices. The policy is defined by a set of rules using a rule language described in the usbguard-rules.conf file. The policy and the authorization state of USB devices can be modified during runtime using the usbguard tool. The system administrator (SA) must work with the site information system security officer (ISSO) to determine a list of authorized peripherals and establish rules within the USBGuard software framework to allow only authorized devices. Check_Content Verify the USBGuard has a policy configured using the following command: $ usbguard list-rules allow id 1d6b:0001 serial If the command does not return results or an error is returned, ask the SA to indicate how unauthorized peripherals are being blocked. If there is no evidence that unauthorized peripherals are being blocked before establishing a connection, this is a finding. If the system is a virtual machine with no virtual or physical USB peripherals attached, this is not a finding. Fix_Text Configure the operating system to enable blocking of unauthorized peripherals using the following command: Note: This command must be run from a root shell and will create an allow list for any usb devices currently connect to the system. # usbguard generate-policy --no-hash > /etc/usbguard/rules.conf Note: Enabling and starting usbguard without properly configuring it for an individual system will immediately prevent any access over a usb device such as a keyboard or mouse. Not_Reviewed Vuln_Num V-282597 Rule_ID SV-282597r1200771_rule Severity medium Rule_Title TOSS 5 must prohibit the use of cached authenticators after one day. Vuln_Discuss If cached authentication information is out of date, the validity of the authentication information may be questionable. Check_Content Verify the System Security Services Daemon (SSSD) prohibits the use of cached authentications after one day. Note: If smart card authentication is not being used on the system, this requirement is not applicable. Check that SSSD allows cached authentications using the following command: $ sudo grep cache_credentials /etc/sssd/sssd.conf cache_credentials = true If "cache_credentials" is set to "false" or missing from the configuration file, this is not a finding and no further checks are required. If "cache_credentials" is set to "true", check that SSSD prohibits the use of cached authentications after one day using the following command: $ sudo grep offline_credentials_expiration /etc/sssd/sssd.conf offline_credentials_expiration = 1 If "offline_credentials_expiration" is not set to a value of "1", this is a finding. Fix_Text Configure the SSSD to prohibit the use of cached authentications after one day. Add or change the following line in "/etc/sssd/sssd.conf" just below the line [pam]: offline_credentials_expiration = 1 Not_Reviewed Vuln_Num V-282598 Rule_ID SV-282598r1200774_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/faillock. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/faillock" using the following command: $ sudo auditctl -l | grep /var/log/faillock -w /var/log/faillock -p wa -k logins If the command does not return a line or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/faillock". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /var/log/faillock -p wa -k logins Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282599 Rule_ID SV-282599r1201494_rule Severity medium Rule_Title TOSS 5 must generate audit records for all account creations, modifications, disabling, and termination events that affect /var/log/tallylog. Vuln_Discuss Without generating audit records specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Satisfies: SRG-OS-000392-GPOS-00172, SRG-OS-000477-GPOS-00222 Check_Content Verify TOSS 5 generates audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/tallylog" using the following command: $ sudo auditctl -l | grep /var/log/tallylog -w /var/log/tallylog -p wa -k logins If the command does not return a line, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to generate audit records for all account creations, modifications, disabling, and termination events that affect "/var/log/tallylog". Add or update the following file system rule to "/etc/audit/rules.d/audit.rules": -w /var/log/tallylog -p wa -k logins Restart the audit daemon for the changes to take effect. Not_Reviewed Vuln_Num V-282601 Rule_ID SV-282601r1200783_rule Severity high Rule_Title TOSS 5 must have the crypto-policies package installed. Vuln_Discuss Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. Check_Content Verify the TOSS 5 "crypto-policies" package is installed using the following command: $ sudo dnf list --installed crypto-policies Example output: crypto-policies.noarch 20220223-1.git5203b41.el9_0.1 If the "crypto-policies" package is not installed, this is a finding. Fix_Text Install the "crypto-policies package" using the following command: $ sudo dnf install crypto-policies Not_Reviewed Vuln_Num V-282602 Rule_ID SV-282602r1200786_rule Severity medium Rule_Title TOSS 5 crypto policy must not be overridden. Vuln_Discuss Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. Check_Content Verify TOSS 5 custom crypto policies are loaded correctly. List all of the crypto backends configured on the system. $ ls -l /etc/crypto-policies/back-ends/ lrwxrwxrwx. 1 root root 40 Oct 7 08:44 bind.config -> /usr/share/crypto-policies/FIPS/bind.txt lrwxrwxrwx. 1 root root 42 Oct 7 08:44 gnutls.config -> /usr/share/crypto-policies/FIPS/gnutls.txt lrwxrwxrwx. 1 root root 40 Oct 7 08:44 java.config -> /usr/share/crypto-policies/FIPS/java.txt lrwxrwxrwx. 1 root root 46 Oct 7 08:44 javasystem.config -> /usr/share/crypto-policies/FIPS/javasystem.txt lrwxrwxrwx. 1 root root 40 Oct 7 08:44 krb5.config -> /usr/share/crypto-policies/FIPS/krb5.txt lrwxrwxrwx. 1 root root 45 Oct 7 08:44 libreswan.config -> /usr/share/crypto-policies/FIPS/libreswan.txt lrwxrwxrwx. 1 root root 42 Oct 7 08:44 libssh.config -> /usr/share/crypto-policies/FIPS/libssh.txt lrwxrwxrwx. 1 root root 39 Oct 7 08:44 nss.config -> /usr/share/crypto-policies/FIPS/nss.txt lrwxrwxrwx. 1 root root 43 Oct 7 08:44 openssh.config -> /usr/share/crypto-policies/FIPS/openssh.txt lrwxrwxrwx. 1 root root 49 Oct 7 08:44 opensshserver.config -> /usr/share/crypto-policies/FIPS/opensshserver.txt lrwxrwxrwx. 1 root root 46 Oct 7 08:44 opensslcnf.config -> /usr/share/crypto-policies/FIPS/opensslcnf.txt lrwxrwxrwx. 1 root root 43 Oct 7 08:44 openssl.config -> /usr/share/crypto-policies/FIPS/openssl.txt If the paths do not point the respective files under "/usr/share/crypto-policies/FIPS" path, this is a finding. Fix_Text Configure TOSS 5 to FIPS crypto policy. $ sudo ln -s /usr/share/crypto-policies/FIPS/<service>.txt /etc/crypto-policies/back-ends/<service>.conf Replace <service> with every service that is not set to FIPS. Restart the system for the changes to take effect. Not_Reviewed Vuln_Num V-282603 Rule_ID SV-282603r1200789_rule Severity medium Rule_Title TOSS 5 must implement a systemwide encryption policy. Vuln_Discuss Centralized cryptographic policies simplify applying secure ciphers across an operating system and the applications that run on that operating system. Use of weak or untested encryption algorithms undermines the purposes of using encryption to protect data. Check_Content Verify the TOSS 5 cryptography policy has been configured correctly with the following commands: $ sudo update-crypto-policies --show FIPS:OSPP If the cryptography base profile is not set to "FIPS" and is not applied, this is a finding. $ sudo update-crypto-policies --check The configured policy matches the generated policy If the command does not return "The configured policy matches the generated policy", this is a finding. Fix_Text Configure TOSS 5 to implement FIPS mode with the following command: $ sudo update-crypto-policies --set FIPS:OSPP Reboot the system for the changes to take effect. Not_Reviewed Vuln_Num V-282605 Rule_ID SV-282605r1200795_rule Severity medium Rule_Title TOSS 5 must protect against or limit the effects of denial-of-service (DoS) attacks by ensuring rate-limiting measures on impacted network interfaces are implemented. Vuln_Discuss DoS is a condition when a resource is not available for legitimate users. When this occurs, the organization either cannot accomplish its mission or must operate at degraded capacity. This requirement addresses the configuration of TOSS 5 to mitigate the impact of DoS attacks that have occurred or are ongoing on system availability. For each system, known and potential DoS attacks must be identified and solutions for each type implemented. A variety of technologies exists to limit or, in some cases, eliminate the effects of DoS attacks (e.g., limiting processes or establishing memory partitions). Employing increased capacity and bandwidth, combined with service redundancy, may reduce the susceptibility to some DoS attacks. Check_Content Verify "nftables" is configured to allow rate limits on any connection to the system using the following command: $ sudo grep -i firewallbackend /etc/firewalld/firewalld.conf # FirewallBackend FirewallBackend=nftables If the "nftables" is not set as the "FirewallBackend" default, this is a finding. Fix_Text Configure "nftables" to be the default "firewallbackend" for "firewalld" by adding or editing the following line in "etc/firewalld/firewalld.conf": FirewallBackend=nftables Establish rate-limiting rules based on organization-defined types of DoS attacks on impacted network interfaces. Not_Reviewed Vuln_Num V-282606 Rule_ID SV-282606r1201360_rule Severity medium Rule_Title All TOSS 5 networked systems must have SSH installed. Vuln_Discuss Without protecting the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190 Check_Content Verify TOSS 5 has the "openssh-server" package installed using the following command: $ sudo dnf list --installed openssh-server Example output: openssh-server.x86_64 8.7p1-8.el9 If the "openssh-server" package is not installed, this is a finding. Fix_Text Install the "openssh-server" package using the following command: $ sudo dnf install openssh-server Not_Reviewed Vuln_Num V-282607 Rule_ID SV-282607r1200801_rule Severity medium Rule_Title All TOSS 5 networked systems must have and implement SSH to protect the confidentiality and integrity of transmitted and received information, as well as information during preparation for transmission. Vuln_Discuss Without protecting the transmitted information, confidentiality and integrity may be compromised because unprotected communications can be intercepted and either read or altered. This requirement applies to both internal and external networks and all types of information system components from which information can be transmitted (e.g., servers, mobile devices, notebook computers, printers, copiers, scanners, and facsimile machines). Communication paths outside the physical protection of a controlled boundary are exposed to the possibility of interception and modification. Protecting the confidentiality and integrity of organizational information can be accomplished by physical means (e.g., employing physical distribution systems) or by logical means (e.g., employing cryptographic techniques). If physical means of protection are employed, then logical means (cryptography) do not have to be employed, and vice versa. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000424-GPOS-00188, SRG-OS-000425-GPOS-00189, SRG-OS-000426-GPOS-00190 Check_Content Verify "sshd" is active using the following command: $ systemctl is-active sshd active If the "sshd" service is not active, this is a finding. Fix_Text Enable the "sshd" service using the following command: $ systemctl enable --now sshd Not_Reviewed Vuln_Num V-282608 Rule_ID SV-282608r1200804_rule Severity medium Rule_Title TOSS 5 must implement DOD or other applicable U.S. Government agency-approved encryption in the bind package. Vuln_Discuss Without cryptographic integrity protections, information can be altered by unauthorized users without detection. Cryptographic mechanisms used for protecting the integrity of information include, for example, signed hash functions using asymmetric cryptography enabling distribution of the public key to verify the hash information while maintaining the confidentiality of the secret key used to generate the hash. TOSS 5 incorporates systemwide crypto policies by default. The employed algorithms can be viewed in the /etc/crypto-policies/back-ends/ directory. Satisfies: SRG-OS-000423-GPOS-00187, SRG-OS-000426-GPOS-00190 Check_Content Verify BIND uses the system crypto policy using the following command: Note: If the "bind" package is not installed, this requirement is not applicable. $ sudo grep include /etc/named.conf include "/etc/crypto-policies/back-ends/bind.config";' If BIND is installed and the BIND config file does not include the "/etc/crypto-policies/back-ends/bind.config" directive, or the line is commented out, this is a finding. Fix_Text Configure BIND to use the system crypto policy. Add the following line to the "options" section in "/etc/named.conf": include "/etc/crypto-policies/back-ends/bind.config"; Not_Reviewed Vuln_Num V-282610 Rule_ID SV-282610r1200810_rule Severity medium Rule_Title TOSS 5 must implement nonexecutable data to protect its memory from unauthorized code execution. Vuln_Discuss ExecShield uses the segmentation feature on all x86 systems to prevent execution in memory higher than a certain address. It writes an address as a limit in the code segment descriptor, to control where code can be executed, on a per-process basis. When the kernel places a process's memory regions such as the stack and heap higher than this address, the hardware prevents execution in that address range. This is enabled by default on the latest Red Hat and Fedora systems if supported by the hardware. Check_Content Verify ExecShield is enabled on 64-bit TOSS 5 systems using the following command: $ sudo dmesg | grep '[NX|DX]*protection' [ 0.000000] NX (Execute Disable) protection: active If "dmesg" does not show "NX (Execute Disable) protection" active, this is a finding. Fix_Text Update the GRUB 2 bootloader configuration. Run the following command: $ sudo grubby --update-kernel=ALL --remove-args=noexec Not_Reviewed Vuln_Num V-282611 Rule_ID SV-282611r1200813_rule Severity low Rule_Title TOSS 5 must remove all software components after updated versions have been installed. Vuln_Discuss Previous versions of software components that are not removed from the information system after updates have been installed may be exploited by adversaries. Check_Content Verify TOSS 5 removes all software components after updated versions have been installed using the following command: $ grep clean /etc/dnf/dnf.conf clean_requirements_on_remove=1 If "clean_requirements_on_remove" is not set to "1", this is a finding. Fix_Text Configure TOSS 5 to remove all software components after updated versions have been installed. Edit the file /etc/dnf/dnf.conf by adding or editing the following line: clean_requirements_on_remove=1 Not_Reviewed Vuln_Num V-282613 Rule_ID SV-282613r1201304_rule Severity medium Rule_Title TOSS 5 must enable the "SELinux" targeted policy. Vuln_Discuss Setting the SELinux policy to "targeted" or a more specialized policy ensures the system will confine processes that are likely to be targeted for exploitation, such as network or system services. Note: During the development or debugging of SELinux modules, it is common to temporarily place nonproduction systems in "permissive" mode. In such temporary cases, SELinux policies should be developed, and once work is completed, the system should be reconfigured to "targeted". Check_Content Note: At lower classification levels (CUI, Secret) where vast amounts of data are processed and a performance impact is occurring, an authorizing official can consider this requirement not applicable. Check that TOSS verifies correct operation of all security functions. Determine if "SELinux" is active and is enforcing the targeted policy using the following command: $ sudo sestatus SELinux status: enabled SELinuxfs mount: /sys/fs/selinux SELinux root directory: /etc/selinux Loaded policy name: targeted Current mode: enforcing Mode from config file: enforcing Policy MLS status: enabled Policy deny_unknown status: allowed Memory protection checking: actual (secure) Max kernel policy version: 33 If the "Loaded policy name" is not set to "targeted", this is a finding. Verify the "/etc/selinux/config" file is configured with the "SELINUXTYPE" of "targeted": $ sudo grep -i "selinuxtype" /etc/selinux/config | grep -v '^#' SELINUXTYPE = targeted If no results are returned, or "SELINUXTYPE" is not set to "targeted", this is a finding. Fix_Text Configure the operating system to verify correct operation of all security functions. Set the "SELinuxtype" to the "targeted" policy by modifying the "/etc/selinux/config" file to have the following line: SELINUXTYPE=targeted Restart the system for the changes to take effect. Not_Reviewed Vuln_Num V-282615 Rule_ID SV-282615r1201495_rule Severity high Rule_Title TOSS 5 crypto policy files must match files shipped with the operating system. Vuln_Discuss The TOSS 5 package "crypto-policies" defines the cryptography policies for the system. If the files are changed from those shipped with the operating system, it may be possible for TOSS 5 to use cryptographic functions that are not FIPS 140-3 approved. Check_Content Verify the TOSS 5 package "crypto-policies" has not been modified using the following command: $ rpm -V crypto-policies If the command has any output, this is a finding. Fix_Text Reinstall the "crypto-policies" package to remove any modifications. $ sudo dnf reinstall crypto-policies Not_Reviewed Vuln_Num V-282616 Rule_ID SV-282616r1200828_rule Severity medium Rule_Title TOSS 5 must have the rsyslog package installed. Vuln_Discuss "rsyslogd" is a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Couple this utility with "gnutls" (which is a secure communications library implementing the SSL, TLS, and DTLS protocols), to create a method to securely encrypt and offload auditing. Check_Content Verify TOSS 5 has the "rsyslogd" package installed using the following command: $ sudo dnf list --installed rsyslog Example output: rsyslog.x86_64 8.2102.0-101.el9_0.1 If the "rsyslogd" package is not installed, this is a finding. Fix_Text Install the "rsyslogd" package using the following command: $ sudo dnf install rsyslogd Not_Reviewed Vuln_Num V-282617 Rule_ID SV-282617r1201621_rule Severity medium Rule_Title TOSS 5 must be configured to forward audit records via TCP to a different system or media from the system being audited via rsyslog. Vuln_Discuss Information stored in one location is vulnerable to accidental or incidental deletion or alteration. Offloading is a common process in information systems with limited audit storage capacity. TOSS 5 installation media provides "rsyslogd", a system utility providing support for message logging. Support for both internet and Unix domain sockets enables this utility to support both local and remote logging. Coupling this utility with "gnutls" (a secure communications library implementing the SSL, TLS, and DTLS protocols) creates a method to securely encrypt and offload auditing. Rsyslog provides three ways to forward message: the traditional UDP transport, which is extremely lossy but standard; the plain TCP based transport, which loses messages only during certain situations but is widely available; and the RELP transport, which does not lose messages but is currently available only as part of the rsyslogd 3.15.0 and above. Examples of each configuration: UDP *.* @remotesystemname TCP *.* @@remotesystemname RELP *.* :omrelp:remotesystemname:2514 Note that a port number was given as there is no standard port for RELP. Check_Content Verify TOSS 5 audit system offloads audit records onto a different system or media from the system being audited via rsyslog using TCP using the following command: $ sudo grep @@ /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.* @@[remoteloggingserver]:[port] If a remote server is not configured, or the line is commented out, ask the system administrator (SA) to indicate how the audit logs are offloaded to a different system or media. If there is no evidence that the audit logs are being offloaded to another system or media, this is a finding. Fix_Text Configure TOSS 5 to offload audit records onto a different system or media from the system being audited via TCP using rsyslog by specifying the remote logging server in "/etc/rsyslog.conf"" or "/etc/rsyslog.d/[customfile].conf" with the name or IP address of the log aggregation server. *.* @@[remoteloggingserver]:[port]" Not_Reviewed Vuln_Num V-282618 Rule_ID SV-282618r1200834_rule Severity medium Rule_Title TOSS 5 must prevent the use of dictionary words for passwords. Vuln_Discuss Using a complex password helps to increase the time and resources required to compromise the password. Password complexity, or strength, is a measure of the effectiveness of a password in resisting attempts at guessing and brute-force attacks. If TOSS 5 allows the user to select passwords based on dictionary words, this increases the chances of password compromise by increasing the opportunity for successful guesses, and brute-force attacks. Check_Content Verify TOSS 5 prevents using dictionary words for passwords using the following command: $ sudo grep dictcheck /etc/security/pwquality.conf /etc/pwquality.conf.d/*.conf /etc/security/pwquality.conf:dictcheck=1 If "dictcheck" does not have a value other than "0" or is commented out, this is a finding. Fix_Text Configure TOSS 5 to prevent the use of dictionary words for passwords. Add or update the following line in the "/etc/security/pwquality.conf" file or a configuration file in the /etc/pwquality.conf.d/ directory to contain the "dictcheck" parameter: dictcheck=1 Not_Reviewed Vuln_Num V-282619 Rule_ID SV-282619r1200837_rule Severity medium Rule_Title TOSS 5 must enforce a delay of at least four seconds between logon prompts following a failed logon attempt. Vuln_Discuss Increasing the time between a failed authentication attempt and reprompting to enter credentials helps to slow a single-threaded brute force attack. Check_Content Verify TOSS 5 enforces a delay of at least four seconds between console logon prompts following a failed logon attempt using the following command: $ grep -i fail_delay /etc/login.defs FAIL_DELAY 4 If the value of "FAIL_DELAY" is not set to "4" or greater or the line is commented out, this is a finding. Fix_Text Configure the TOSS 5 to enforce a delay of at least four seconds between logon prompts following a failed console logon attempt. Modify the "/etc/login.defs" file to set the "FAIL_DELAY" parameter to 4 or greater: FAIL_DELAY 4 Not_Reviewed Vuln_Num V-282620 Rule_ID SV-282620r1200840_rule Severity medium Rule_Title TOSS 5 must disable virtual system calls. Vuln_Discuss System calls are special routines in the Linux kernel which userspace applications ask to do privileged tasks. Invoking a system call is an expensive operation because the processor must interrupt the currently executing task, switch context to kernel mode, and then back to userspace after the system call completes. Virtual system calls map into user space a page that contains some variables and the implementation of some system calls. This allows the system calls to be executed in userspace to alleviate the context switching expense. Virtual system calls provide an opportunity of attack for a user who has control of the return instruction pointer. Disabling virtual system calls help to prevent return-oriented programming (ROP) attacks via buffer overflows and overruns. If the system intends to run containers based on RHEL 6 components, then virtual system calls must be enabled for the components to function properly. Check_Content Verify the current GRUB 2 configuration disables virtual system calls using the following command: $ sudo grubby --info=ALL | grep args | grep -v 'vsyscall=none' If any output is returned and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Document the use of virtual system calls with the ISSO as an operational requirement or disable them using the following command: $ sudo grubby --update-kernel=ALL --args="vsyscall=none" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="vsyscall=none" Not_Reviewed Vuln_Num V-282621 Rule_ID SV-282621r1200843_rule Severity medium Rule_Title TOSS 5 must clear the page allocator to prevent use-after-free attacks. Vuln_Discuss Poisoning writes an arbitrary value to freed pages, so any modification or reference to that page after being freed or before being initialized will be detected and prevented. This prevents many types of use-after-free vulnerabilities at little performance cost. Also prevents leak of data and detection of corrupted memory. Check_Content Verify GRUB 2 is configured to enable page poisoning to mitigate use-after-free vulnerabilities. Check that the current GRUB 2 configuration has page poisoning enabled using the following command: $ sudo grubby --info=ALL | grep args | grep -v 'page_poison=1' If any output is returned, this is a finding. Fix_Text Configure TOSS 5 to enable page poisoning with the following commands: $ sudo grubby --update-kernel=ALL --args="page_poison=1" Add or modify the following line in "/etc/default/grub" to ensure the configuration survives kernel updates: GRUB_CMDLINE_LINUX="page_poison=1" Not_Reviewed Vuln_Num V-282622 Rule_ID SV-282622r1201309_rule Severity medium Rule_Title TOSS 5 must disable the kernel.core_pattern. Vuln_Discuss A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems. Check_Content Verify TOSS 5 disables storing core dumps with the following commands: $ sudo sysctl kernel.core_pattern kernel.core_pattern = |/bin/false If the returned line does not have a value of "|/bin/false", or a line is not returned and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure TOSS 5 to disable storing core dumps. Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.core_pattern = |/bin/false Reload the system configuration files for the changes to take effect. $ sudo sysctl --system Not_Reviewed Vuln_Num V-282623 Rule_ID SV-282623r1201600_rule Severity high Rule_Title TOSS 5 must be a vendor-supported release. Vuln_Discuss An operating system release is considered supported if the vendor continues to provide security patches for the product. With an unsupported release, it will not be possible to resolve security issues discovered in the system software. Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000830-GPOS-00300 Check_Content Verify the version of TOSS 5 is vendor supported using the following command: $ cat /etc/toss-release toss-release-5.1-1 If the installed version of TOSS 5 is not supported, this is a finding. Fix_Text Upgrade to a supported version of TOSS 5. Not_Reviewed Vuln_Num V-282624 Rule_ID SV-282624r1200852_rule Severity medium Rule_Title TOSS 5 vendor packaged system security patches and updates must be installed and up to date. Vuln_Discuss Installing software updates is a fundamental mitigation against the exploitation of publicly known vulnerabilities. If the most recent security patches and updates are not installed, unauthorized users may take advantage of weaknesses in the unpatched software. The lack of prompt attention to patching could result in a system compromise. Check_Content Verify TOSS 5 security patches and updates are installed and up to date. Updates are required in a frequency determined by organizational policy. Check the TOSS release notes sent via email for security updates. It is important to note that updates provided by Red Hat/TOSS may not be present on the system if the underlying packages are not installed. Check that the available package security updates have been installed on the system using the following command: $ dnf history list | more ID | Command line | Date and time | Action(s) | Altered ------------------------------------------------------------------------------- 70 | install aide | 2023-03-05 10:58 | Install | 1 69 | update -y | 2023-03-04 14:34 | Update | 18 EE 68 | install vlc | 2023-02-21 17:12 | Install | 21 67 | update -y | 2023-02-21 17:04 | Update | 7 EE Typical update frequency may be overridden by Information Assurance Vulnerability Alert (IAVA) notifications from CYBERCOM. If the system is not compliant with the organizational patching policy, this is a finding. Fix_Text Install TOSS 5 security patches and updates at the organizationally defined frequency. If system updates are installed via a centralized repository that is configured on the system, install all updates using the following command: $ sudo dnf update Not_Reviewed Vuln_Num V-282625 Rule_ID SV-282625r1200855_rule Severity medium Rule_Title The graphical display manager must not be the default target on TOSS 5 unless approved. Vuln_Discuss Unnecessary service packages must not be installed to decrease the attack surface of the system. Graphical display managers have a long history of security vulnerabilities and must not be used unless approved and documented. Check_Content Verify TOSS 5 is configured to boot to the command line: $ systemctl get-default multi-user.target If the system default target is not set to "multi-user.target" and the information system security officer (ISSO) lacks a documented requirement for a graphical user interface, this is a finding. Fix_Text Document the requirement for a graphical user interface with the ISSO or set the default target to "multi-user" using the following command: $ sudo systemctl set-default multi-user.target Not_Reviewed Vuln_Num V-282626 Rule_ID SV-282626r1200858_rule Severity low Rule_Title TOSS 5 must enable the hardware random number generator entropy gatherer service. Vuln_Discuss The most important characteristic of a random number generator is its randomness, namely its ability to deliver random numbers that are impossible to predict. Entropy in computer security is associated with the unpredictability of a source of randomness. The random source with high entropy tends to achieve a uniform distribution of random values. Random number generators are one of the most important building blocks of cryptosystems. The "rngd" service feeds random data from hardware device to kernel random device. Quality (nonpredictable) random number generation is important for several security functions (i.e., ciphers). Check_Content Verify TOSS 5 enabled the hardware random number generator entropy gatherer service using the following command: Note: For TOSS 5 systems running with kernel FIPS mode enabled as specified by TOSS-05-000470, this requirement is not applicable. $ systemctl is-active rngd active If the "rngd" service is not active, this is a finding. Fix_Text Install the "rng-tools" package using the following command: $ sudo dnf install rng-tools Enable the "rngd" service using the following command: $ sudo systemctl enable --now rngd Not_Reviewed Vuln_Num V-282627 Rule_ID SV-282627r1200861_rule Severity medium Rule_Title TOSS 5 must disable the ability of systemd to spawn an interactive boot process. Vuln_Discuss Using interactive or recovery boot, the console user could disable auditing, firewalls, or other services, thereby weakening system security. Check_Content Verify GRUB 2 is configured to disable interactive boot. Check that the current GRUB 2 configuration disables the ability of systemd to spawn an interactive boot process using the following command: $ sudo grubby --info=ALL | grep args | grep 'systemd.confirm_spawn' If any output is returned, this is a finding. Fix_Text Configure TOSS 5 to allocate sufficient audit_backlog_limit to disable the ability of systemd to spawn an interactive boot process using the following command: $ sudo grubby --update-kernel=ALL --remove-args="systemd.confirm_spawn" Not_Reviewed Vuln_Num V-282628 Rule_ID SV-282628r1200864_rule Severity medium Rule_Title The TOSS 5 /boot/grub2/grub.cfg file must be group owned by root. Vuln_Discuss The "root" group is a highly privileged group. Furthermore, the group owner of this file should not have any access privileges. Check_Content Verify the group ownership of the "/boot/grub2/grub.cfg" file using the following command: $ sudo stat -c "%G %n" /boot/grub2/grub.cfg root /boot/grub2/grub.cfg If "/boot/grub2/grub.cfg" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /boot/grub2/grub.cfg to root using the following command: $ sudo chgrp root /boot/grub2/grub.cfg Not_Reviewed Vuln_Num V-282629 Rule_ID SV-282629r1200867_rule Severity medium Rule_Title The TOSS 5 /boot/grub2/grub.cfg file must be owned by root. Vuln_Discuss The "/boot/grub2/grub.cfg" file stores sensitive system configurations. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/boot/grub2/grub.cfg" file using the following command: $ sudo stat -c "%U %n" /boot/grub2/grub.cfg root /boot/grub2/grub.cfg If "/boot/grub2/grub.cfg" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file "/boot/grub2/grub.cfg" to root using the following command: $ sudo chown root /boot/grub2/grub.cfg Not_Reviewed Vuln_Num V-282630 Rule_ID SV-282630r1200870_rule Severity medium Rule_Title TOSS 5 must prevent loading a new kernel for later execution. Vuln_Discuss Changes to any software components can have significant effects on the overall security of the operating system. This requirement ensures the software has not been tampered with and that it has been provided by a trusted vendor. Disabling "kexec_load" prevents an unsigned kernel image (that could be a windows kernel or modified vulnerable kernel) from being loaded. Kexec can be used subvert the entire secureboot process and should be avoided at all costs especially since it can load unsigned kernel images. Check_Content Verify TOSS 5 is configured to disable kernel image loading using the following command: $ sudo sysctl kernel.kexec_load_disabled kernel.kexec_load_disabled = 1 If "kernel.kexec_load_disabled" is not set to "1" or is missing, this is a finding. Fix_Text Add or edit the following line in a system configuration file in the "/etc/sysctl.d/" directory: kernel.kexec_load_disabled = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282631 Rule_ID SV-282631r1200873_rule Severity medium Rule_Title TOSS 5 must disable core dump backtraces. Vuln_Discuss A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy. Check_Content Verify TOSS 5 disables core dump backtraces using the following command: $ grep -i process /etc/systemd/coredump.conf ProcessSizeMax=0 If the "ProcessSizeMax" item is missing, commented out, or the value is anything other than "0" and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding. Fix_Text Configure TOSS 5 to disable core dump backtraces. Add or modify the following line in /etc/systemd/coredump.conf: ProcessSizeMax=0 Not_Reviewed Vuln_Num V-282632 Rule_ID SV-282632r1200876_rule Severity medium Rule_Title TOSS 5 must disable storing core dumps. Vuln_Discuss A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers or system operators trying to debug problems. Enabling core dumps on production systems is not recommended; however, there may be overriding operational requirements to enable advanced debugging. Permitting temporary enablement of core dumps during such situations must be reviewed through local needs and policy. Check_Content Verify TOSS 5 disables storing core dumps for all users using the following command: $ grep -i storage /etc/systemd/coredump.conf Storage=none If the "Storage" item is missing, commented out, or the value is anything other than "none" and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement for all domains that have the "core" item assigned, this is a finding. Fix_Text Configure TOSS 5 to disable storing core dumps for all users. Add or modify the following line in /etc/systemd/coredump.conf: Storage=none Not_Reviewed Vuln_Num V-282633 Rule_ID SV-282633r1200879_rule Severity medium Rule_Title TOSS 5 must disable acquiring, saving, and processing core dumps. Vuln_Discuss A core dump includes a memory image taken at the time the operating system terminates an application. The memory image could contain sensitive data and is generally useful only for developers trying to debug problems. Check_Content Verify TOSS 5 is not configured to acquire, save, or process core dumps using the following command: $ sudo systemctl status systemd-coredump.socket systemd-coredump.socket Loaded: masked (Reason: Unit systemd-coredump.socket is masked.) Active: inactive (dead) If the "systemd-coredump.socket" is loaded and not masked and the need for core dumps is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure the system to disable the systemd-coredump.socket using the following command: $ sudo systemctl mask --now systemd-coredump.socket Created symlink /etc/systemd/system/systemd-coredump.socket -> /dev/null Reload the daemon for this change to take effect. $ sudo systemctl daemon-reload Not_Reviewed Vuln_Num V-282634 Rule_ID SV-282634r1200882_rule Severity medium Rule_Title TOSS 5 must not have the sendmail package installed. Vuln_Discuss The "sendmail "software was not developed with security in mind, and its design prevents it from being effectively contained by SELinux. Postfix must be used instead. Check_Content Verify the "sendmail" package is not installed using the following command: $ sudo dnf list --installed sendmail Error: No matching Packages to list If the "sendmail" package is installed, this is a finding. Fix_Text Remove the "sendmail" package using the following command: $ sudo dnf remove sendmail Not_Reviewed Vuln_Num V-282635 Rule_ID SV-282635r1201602_rule Severity medium Rule_Title TOSS 5 must not have the quagga package installed. Vuln_Discuss Quagga is a network routing software suite providing implementations of Open Shortest Path First (OSPF), Routing Information Protocol (RIP), and Border Gateway Protocol (BGP) for Unix and Linux platforms. If there is no need to make the router software available, removing it provides a safeguard against its activation. Check_Content Verify the "quagga" package is not installed using the following command: $ sudo dnf list --installed quagga Error: No matching Packages to list If the "quagga" package is installed and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Remove the "quagga" package using the following command: $ sudo dnf remove quagga Not_Reviewed Vuln_Num V-282636 Rule_ID SV-282636r1201310_rule Severity medium Rule_Title TOSS 5 must have the gnutls-utils package installed. Vuln_Discuss GnuTLS is a secure communications library implementing the SSL, TLS, and DTLS protocols and technologies around them. It provides a simple C language application programming interface (API) to access the secure communications protocols as well as APIs to parse and write X.509, PKCS #12, OpenPGP, and other required structures. This package contains command line TLS client and server and certificate manipulation tools. Check_Content Verify TOSS 5 has the "gnutls-utils" package installed using the following command: $ dnf list --installed gnutls-utils Example output: gnutls-utils.x86_64 3.7.3-9.el9 If the "gnutls-utils" package is not installed, this is a finding. Fix_Text Install the "gnutls-utils" package using the following command: $ sudo dnf install gnutls-utils Not_Reviewed Vuln_Num V-282637 Rule_ID SV-282637r1200891_rule Severity medium Rule_Title TOSS 5 must have the nss-tools package installed. Vuln_Discuss Network Security Services (NSS) is a set of libraries designed to support cross-platform development of security-enabled client and server applications. Installing the "nss-tools" package installs command line tools to manipulate the NSS certificate and key database. Check_Content Verify TOSS 5 has the "nss-tools" package installed using the following command: $ dnf list --installed nss-tools Example output: nss-tools.x86_64 3.71.0-7.el9 If the "nss-tools" package is not installed, this is a finding. Fix_Text Install the "nss-tools" package using the following command: $ sudo dnf install nss-tools Not_Reviewed Vuln_Num V-282638 Rule_ID SV-282638r1200894_rule Severity medium Rule_Title TOSS 5 must have the rng-tools package installed. Vuln_Discuss "rng-tools" provides hardware random number generator tools, such as those used in the formation of x509/PKI certificates. Check_Content Verify TOSS 5 has the "rng-tools" package installed using the following command: $ sudo dnf list --installed rng-tools Example output: rng-tools.x86_64 6.14-2.git.b2b7934e.el9 If the "rng-tools" package is not installed, this is a finding. Fix_Text Install the "rng-tools" package using the following command: $ sudo dnf install rng-tools Not_Reviewed Vuln_Num V-282639 Rule_ID SV-282639r1200897_rule Severity medium Rule_Title TOSS 5 must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS. Vuln_Discuss When an NFS server is configured to use RPCSEC_SYS, a selected userid and groupid are used to handle requests from the remote user. The userid and groupid could mistakenly or maliciously be set incorrectly. The RPCSEC_GSS method of authentication uses certificates on the server and client systems to more securely authenticate the remote mount request. Check_Content Verify TOSS 5 has the "sec" option configured for all NFS mounts using the following command: Note: If no NFS mounts are configured, this requirement is not applicable. $ cat /etc/fstab | grep nfs 192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5p:krb5i:krb5 If the system is mounting file systems via NFS and has the sec option without the "krb5:krb5i:krb5p" settings, the "sec" option has the "sys" setting, or the "sec" option is missing, this is a finding. Fix_Text Update the "/etc/fstab" file so the option "sec" is defined for each NFS mounted file system and the "sec" option does not have the "sys" setting. Ensure the "sec" option is defined as "krb5p:krb5i:krb5". Not_Reviewed Vuln_Num V-282640 Rule_ID SV-282640r1200900_rule Severity medium Rule_Title TOSS 5 must prevent special devices on file systems that are imported via Network File System (NFS). Vuln_Discuss The "nodev" mount option causes the system to not interpret character or block special devices. Executing character or block special devices from untrusted file systems increases the opportunity for nonprivileged users to attain unauthorized administrative access. Check_Content Verify TOSS 5 has the "nodev" option configured for all NFS mounts using the following command: Note: If no NFS mounts are configured, this requirement is not applicable. $ cat /etc/fstab | grep nfs 192.168.22.2:/mnt/export /data nfs4 rw,nosuid,nodev,noexec,sync,soft,sec=krb5:krb5i:krb5p If the system is mounting file systems via NFS and the "nodev" option is missing, this is a finding. Fix_Text Update each NFS mounted file system to use the "nodev" option on file systems that are being imported via NFS. Not_Reviewed Vuln_Num V-282641 Rule_ID SV-282641r1200903_rule Severity medium Rule_Title TOSS 5 cron configuration directories must have a mode of 0700 or less permissive. Vuln_Discuss Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should have the correct access rights to prevent unauthorized changes. Check_Content Verify the permissions of the cron directories using the following command: $ find /etc/cron* -type d | xargs stat -c "%a %n" 700 /etc/cron.d 700 /etc/cron.daily 700 /etc/cron.hourly 700 /etc/cron.monthly 700 /etc/cron.weekly If any cron configuration directory is more permissive than "700", this is a finding. Fix_Text Configure any TOSS 5 cron configuration directory with a mode more permissive than "0700" as follows: $ sudo chmod 0700 [cron configuration directory] Not_Reviewed Vuln_Num V-282642 Rule_ID SV-282642r1200906_rule Severity medium Rule_Title All TOSS 5 local initialization files must have mode 0740 or less permissive. Vuln_Discuss Local initialization files are used to configure the user's shell environment upon logon. Maliciously modifying these files could compromise accounts upon logon. Check_Content Verify all local initialization files have a mode of "0740" or less permissive using the following command: Note: The example will be for the "wadea" user, who has a home directory of "/home/wadea". $ sudo ls -al /home/wadea/.[^.]* | more -rwxr---- 1 wadea users 896 Mar 10 2011 .profile -rwxr---- 1 wadea users 497 Jan 6 2007 .login -rwxr---- 1 wadea users 886 Jan 6 2007 .something If any local initialization files have a mode more permissive than "0740", and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Set the mode of the local initialization files to "0740" using the following command: Note: The example will be for the wadea user, who has a home directory of "/home/wadea". $ sudo chmod 0740 /home/wadea/.<INIT_FILE> Not_Reviewed Vuln_Num V-282643 Rule_ID SV-282643r1200909_rule Severity medium Rule_Title All TOSS 5 local interactive user home directories must have mode 0770 or less permissive. Vuln_Discuss Excessive permissions on local interactive user home directories may allow unauthorized access to user files by other users. Check_Content Verify the assigned home directory of all local interactive users has a mode of "0770" or less permissive using the following command: Note: This may miss interactive users that have been assigned a privileged user identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. $ sudo ls -ld $(awk -F: '($3>=1000)&&($7 !~ /nologin/){print $6}' /etc/passwd) drwxrwx--- 2 wadea admin 4096 Jun 5 12:41 wadea If home directories referenced in "/etc/passwd" do not have a mode of "0770" or less permissive, this is a finding. Fix_Text Change the mode of interactive user's home directories to "0770". To change the mode of a local interactive user's home directory, use the following command: Note: The example will be for the user "wadea". $ sudo chmod 0770 /home/wadea Not_Reviewed Vuln_Num V-282644 Rule_ID SV-282644r1200912_rule Severity medium Rule_Title The TOSS 5 /etc/group file must have mode 0644 or less permissive to prevent unauthorized access. Vuln_Discuss The "/etc/group" file contains information regarding groups that are configured on the system. Protecting this file is important for system security. Check_Content Verify the "/etc/group" file has mode "0644" or less permissive using the following command: $ sudo stat -c "%a %n" /etc/group 644 /etc/group If a value of "0644" or less permissive is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/group" to "0644" using the following command: $ sudo chmod 0644 /etc/group Not_Reviewed Vuln_Num V-282645 Rule_ID SV-282645r1200915_rule Severity medium Rule_Title The TOSS 5 /etc/group- file must have mode 0644 or less permissive to prevent unauthorized access. Vuln_Discuss The "/etc/group-" file is a backup file of "/etc/group" and thus contains information regarding groups configured on the system. Protecting this file is important for system security. Check_Content Verify the "/etc/group-" file has mode "0644" or less permissive using the following command: $ sudo stat -c "%a %n" /etc/group- 644 /etc/group- If a value of "0644" or less permissive is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/group-" to "0644" using the following command: $ sudo chmod 0644 /etc/group- Not_Reviewed Vuln_Num V-282646 Rule_ID SV-282646r1200918_rule Severity medium Rule_Title The TOSS 5 /etc/gshadow file must have mode 0000 or less permissive to prevent unauthorized access. Vuln_Discuss The "/etc/gshadow" file contains group password hashes. Protecting this file is critical for system security. Check_Content Verify the "/etc/gshadow" file has mode "0000" using the following command: $ sudo stat -c "%a %n" /etc/gshadow 0 /etc/gshadow If a value of "0" is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/gshadow" to "0000" using the following command: $ sudo chmod 0000 /etc/gshadow Not_Reviewed Vuln_Num V-282647 Rule_ID SV-282647r1200921_rule Severity medium Rule_Title The TOSS 5 /etc/gshadow- file must have mode 0000 or less permissive to prevent unauthorized access. Vuln_Discuss The "/etc/gshadow-" file is a backup of "/etc/gshadow" and contains group password hashes. Protecting this file is critical for system security. Check_Content Verify the "/etc/gshadow-" file has mode "0000" using the following command: $ sudo stat -c "%a %n" /etc/gshadow- 0 /etc/gshadow- If a value of "0" is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/gshadow-" to "0000" using the following command: $ sudo chmod 0000 /etc/gshadow- Not_Reviewed Vuln_Num V-282648 Rule_ID SV-282648r1201583_rule Severity medium Rule_Title The TOSS 5 /etc/passwd file must have mode 0644 or less permissive to prevent unauthorized access. Vuln_Discuss If the "/etc/passwd" file is writable by a group owner or the world, it increases the risk of compromise. The file contains the list of accounts on the system and associated information, and protection of this file is critical for system security. Check_Content Verify the "/etc/passwd" file has mode "0644" or less permissive using the following command: $ sudo stat -c "%a %n" /etc/passwd 644 /etc/passwd If a value of "0644" or less permissive is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/passwd" to "0644" using the following command: $ sudo chmod 0644 /etc/passwd Not_Reviewed Vuln_Num V-282649 Rule_ID SV-282649r1200927_rule Severity medium Rule_Title The TOSS 5 /etc/passwd- file must have mode 0644 or less permissive to prevent unauthorized access. Vuln_Discuss The "/etc/passwd-" file is a backup file of "/etc/passwd" and contains information about the users configured on the system. Protecting this file is critical for system security. Check_Content Verify the "/etc/passwd-" file has mode "0644" or less permissive using the following command: $ sudo stat -c "%a %n" /etc/passwd- 644 /etc/passwd- If a value of "0644" or less permissive is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/passwd-" to "0644" using the following command: $ sudo chmod 0644 /etc/passwd- Not_Reviewed Vuln_Num V-282650 Rule_ID SV-282650r1200930_rule Severity medium Rule_Title The TOSS 5 /etc/shadow- file must have mode 0000 or less permissive to prevent unauthorized access. Vuln_Discuss The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protecting this file is critical for system security. Check_Content Verify the "/etc/shadow-" file has mode "0000" using the following command: $ sudo stat -c "%a %n" /etc/shadow- 0 /etc/shadow- If a value of "0" is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/shadow-" to "0000" using the following command: $ sudo chmod 0000 /etc/shadow- Not_Reviewed Vuln_Num V-282651 Rule_ID SV-282651r1200933_rule Severity medium Rule_Title The TOSS 5 /etc/group file must be owned by root. Vuln_Discuss The "/etc/group" file contains information regarding groups that are configured on the system. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/etc/group" file using the following command: $ sudo stat -c "%U %n" /etc/group root /etc/group If "/etc/group" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file "/etc/group" to "root" using the following command: $ sudo chown root /etc/group Not_Reviewed Vuln_Num V-282652 Rule_ID SV-282652r1200936_rule Severity medium Rule_Title The TOSS 5 /etc/group file must be group-owned by root. Vuln_Discuss The "/etc/group" file contains information regarding groups configured on the system. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/group" file using the following command: $ sudo stat -c "%G %n" /etc/group root /etc/group If "/etc/group" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file "/etc/group" to "root" using the following command: $ sudo chgrp root /etc/group Not_Reviewed Vuln_Num V-282653 Rule_ID SV-282653r1200939_rule Severity medium Rule_Title The TOSS 5 /etc/group- file must be owned by root. Vuln_Discuss The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/etc/group-" file using the following command: $ sudo stat -c "%U %n" /etc/group- root /etc/group- If "/etc/group-" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file /etc/group- to root using the following command: $ sudo chown root /etc/group- Not_Reviewed Vuln_Num V-282654 Rule_ID SV-282654r1200942_rule Severity medium Rule_Title The TOSS 5 /etc/group- file must be group-owned by root. Vuln_Discuss The "/etc/group-" file is a backup file of "/etc/group", and as such, contains information regarding groups that are configured on the system. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/group-" file using the following command: $ sudo stat -c "%G %n" /etc/group- root /etc/group- If "/etc/group-" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /etc/group- to root using the following command: $ sudo chgrp root /etc/group- Not_Reviewed Vuln_Num V-282655 Rule_ID SV-282655r1200945_rule Severity medium Rule_Title The TOSS 5 /etc/gshadow file must be owned by root. Vuln_Discuss The "/etc/gshadow" file contains group password hashes. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/etc/gshadow" file using the following command: $ sudo stat -c "%U %n" /etc/gshadow root /etc/gshadow If "/etc/gshadow" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file /etc/gshadow to root using the following command: $ sudo chown root /etc/gshadow Not_Reviewed Vuln_Num V-282656 Rule_ID SV-282656r1200948_rule Severity medium Rule_Title The TOSS 5 /etc/gshadow file must be group-owned by root. Vuln_Discuss The "/etc/gshadow" file contains group password hashes. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/gshadow" file using the following command: $ sudo stat -c "%G %n" /etc/gshadow root /etc/gshadow If "/etc/gshadow" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /etc/gshadow to root using the following command: $ sudo chgrp root /etc/gshadow Not_Reviewed Vuln_Num V-282657 Rule_ID SV-282657r1200951_rule Severity medium Rule_Title The TOSS 5 /etc/gshadow- file must be owned by root. Vuln_Discuss The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/etc/gshadow-" file using the following command: $ sudo stat -c "%U %n" /etc/gshadow- root /etc/gshadow- If "/etc/gshadow-" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file /etc/gshadow- to root using the following command: $ sudo chown root /etc/gshadow- Not_Reviewed Vuln_Num V-282658 Rule_ID SV-282658r1200954_rule Severity medium Rule_Title The TOSS 5 /etc/gshadow- file must be group-owned by root. Vuln_Discuss The "/etc/gshadow-" file is a backup of "/etc/gshadow", and as such, contains group password hashes. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/gshadow-" file using the following command: $ sudo stat -c "%G %n" /etc/gshadow- root /etc/gshadow- If "/etc/gshadow-" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /etc/gshadow- to root using the following command: $ sudo chgrp root /etc/gshadow- Not_Reviewed Vuln_Num V-282659 Rule_ID SV-282659r1200957_rule Severity medium Rule_Title The TOSS 5 /etc/passwd file must be owned by root. Vuln_Discuss The "/etc/passwd" file contains information about the users that are configured on the system. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/etc/passwd" file using the following command: $ sudo stat -c "%U %n" /etc/passwd root /etc/passwd If "/etc/passwd" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file /etc/passwd to root using the following command: $ sudo chown root /etc/passwd Not_Reviewed Vuln_Num V-282660 Rule_ID SV-282660r1200960_rule Severity medium Rule_Title The TOSS 5 /etc/passwd file must be group-owned by root. Vuln_Discuss The "/etc/passwd" file contains information about the users that are configured on the system. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/passwd" file using the following command: $ sudo stat -c "%G %n" /etc/passwd root /etc/passwd If "/etc/passwd" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /etc/passwd to root using the following command: $ sudo chgrp root /etc/passwd Not_Reviewed Vuln_Num V-282661 Rule_ID SV-282661r1200963_rule Severity medium Rule_Title The TOSS 5 /etc/passwd- file must be owned by root. Vuln_Discuss The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/etc/passwd-" file using the following command: $ sudo stat -c "%U %n" /etc/passwd- root /etc/passwd- If "/etc/passwd-" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file /etc/passwd- to root using the following command: $ sudo chown root /etc/passwd- Not_Reviewed Vuln_Num V-282662 Rule_ID SV-282662r1200966_rule Severity medium Rule_Title The TOSS 5 /etc/passwd- file must be group-owned by root. Vuln_Discuss The "/etc/passwd-" file is a backup file of "/etc/passwd", and as such, contains information about the users that are configured on the system. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/passwd-" file using the following command: $ sudo stat -c "%G %n" /etc/passwd- root /etc/passwd- If "/etc/passwd-" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /etc/passwd- to root using the following command: $ sudo chgrp root /etc/passwd- Not_Reviewed Vuln_Num V-282663 Rule_ID SV-282663r1200969_rule Severity medium Rule_Title The TOSS 5 /etc/shadow file must be owned by root. Vuln_Discuss The "/etc/shadow" file contains the list of local system accounts and stores password hashes. Protecting this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information, which could weaken the system security posture. Check_Content Verify the ownership of the "/etc/shadow" file using the following command: $ sudo stat -c "%U %n" /etc/shadow root /etc/shadow If "/etc/shadow" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file /etc/shadow to root using the following command: $ sudo chown root /etc/shadow Not_Reviewed Vuln_Num V-282664 Rule_ID SV-282664r1200972_rule Severity medium Rule_Title The TOSS 5 /etc/shadow file must be group-owned by root. Vuln_Discuss The "/etc/shadow" file stores password hashes. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/shadow" file using the following command: $ sudo stat -c "%G %n" /etc/shadow root /etc/shadow If "/etc/shadow" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /etc/shadow to root using the following command: $ sudo chgrp root /etc/shadow Not_Reviewed Vuln_Num V-282665 Rule_ID SV-282665r1200975_rule Severity medium Rule_Title The TOSS 5 /etc/shadow- file must be owned by root. Vuln_Discuss The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protecting this file is critical for system security. Check_Content Verify the ownership of the "/etc/shadow-" file using the following command: $ sudo stat -c "%U %n" /etc/shadow- root /etc/shadow- If "/etc/shadow-" file does not have an owner of "root", this is a finding. Fix_Text Change the owner of the file /etc/shadow- to root using the following command: $ sudo chown root /etc/shadow- Not_Reviewed Vuln_Num V-282666 Rule_ID SV-282666r1200978_rule Severity medium Rule_Title The TOSS 5 /etc/shadow- file must be group-owned by root. Vuln_Discuss The "/etc/shadow-" file is a backup file of "/etc/shadow", and as such, contains the list of local system accounts and password hashes. Protecting this file is critical for system security. Check_Content Verify the group ownership of the "/etc/shadow-" file using the following command: $ sudo stat -c "%G %n" /etc/shadow- root /etc/shadow- If "/etc/shadow-" file does not have a group owner of "root", this is a finding. Fix_Text Change the group of the file /etc/shadow- to root using the following command: $ sudo chgrp root /etc/shadow- Not_Reviewed Vuln_Num V-282667 Rule_ID SV-282667r1200981_rule Severity medium Rule_Title The TOSS 5 cron configuration files directory must be owned by root. Vuln_Discuss Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations; therefore, service configuration files must be owned by the correct group to prevent unauthorized changes. Check_Content Verify the ownership of all cron configuration files with the command: $ stat -c "%U %n" /etc/cron* root /etc/cron.d root /etc/cron.daily root /etc/cron.deny root /etc/cron.hourly root /etc/cron.monthly root /etc/crontab root /etc/cron.weekly If any crontab is not owned by root, this is a finding. Fix_Text Configure any cron configuration not owned by root using the following command: $ sudo chown root [cron config file] Not_Reviewed Vuln_Num V-282668 Rule_ID SV-282668r1200984_rule Severity medium Rule_Title The TOSS 5 cron configuration files directory must be group-owned by root. Vuln_Discuss Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations; therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. Check_Content Verify the group ownership of all cron configuration files using the following command: $ stat -c "%G %n" /etc/cron* root /etc/cron.d root /etc/cron.daily root /etc/cron.deny root /etc/cron.hourly root /etc/cron.monthly root /etc/crontab root /etc/cron.weekly If any crontab is not group owned by root, this is a finding. Fix_Text Configure any cron configuration not group-owned by root using the following command: $ sudo chgrp root [cron config file] Not_Reviewed Vuln_Num V-282669 Rule_ID SV-282669r1200987_rule Severity medium Rule_Title All TOSS 5 world-writable directories must be owned by root, sys, bin, or an application user. Vuln_Discuss If a world-writable directory is not owned by root, sys, bin, or an application user identifier (UID), unauthorized users may be able to modify files created by others. The only authorized public directories are those temporary directories supplied with the system or those designed to be temporary file repositories. The setting is normally reserved for directories used by the system and by users for temporary file storage, (e.g., /tmp), and for directories requiring global read/write access. Check_Content Verify world writable directories are owned by root, a system account, or an application account. The following command will discover and print world-writable directories that are not owned by root. Run it once for each local partition [PART]: $ sudo find PART -xdev -type d -perm -0002 -uid +0 -print If there is output, this is a finding. Fix_Text Configure all public directories to be owned by root or a system account to prevent unauthorized and unintended information transferred via shared system resources. Set the owner of all public directories as root or a system account using the command, replace "[Public Directory]" with any directory path not owned by root or a system account: $ sudo chown root [Public Directory] Not_Reviewed Vuln_Num V-282670 Rule_ID SV-282670r1200990_rule Severity medium Rule_Title All TOSS 5 local files and directories must have a valid group owner. Vuln_Discuss Files without a valid group owner may be unintentionally inherited if a group is assigned the same Group Identifier (GID) as the GID of the files without a valid group owner. Check_Content Verify all local files and directories on TOSS 5 have a valid group using the following command: $ df --local -P | awk {'if (NR!=1) print $6'} | sudo xargs -I '{}' find '{}' -xdev -nogroup If any files on the system do not have an assigned group, this is a finding. Fix_Text Either remove all files and directories from TOSS 5 that do not have a valid group, or assign a valid group to all files and directories on the system with the "chgrp" command: $ sudo chgrp <group> <file> Not_Reviewed Vuln_Num V-282671 Rule_ID SV-282671r1200993_rule Severity medium Rule_Title All TOSS 5 local files and directories must have a valid owner. Vuln_Discuss Unowned files and directories may be unintentionally inherited if a user is assigned the same user identifier "UID" as the UID of the unowned files. Check_Content Verify all local files and directories on TOSS 5 have a valid owner using the following command: $ df --local -P | awk {'if (NR!=1) print $6'} | sudo xargs -I '{}' find '{}' -xdev -nouser If any files on the system do not have an assigned owner, this is a finding. Fix_Text Either remove all files and directories from the system that do not have a valid user, or assign a valid user to all unowned files and directories on TOSS 5 with the "chown" command: $ sudo chown <user> <file> Not_Reviewed Vuln_Num V-282672 Rule_ID SV-282672r1200996_rule Severity medium Rule_Title TOSS 5 must be configured so that all system device files are correctly labeled to prevent unauthorized modification. Vuln_Discuss If an unauthorized or modified device is allowed to exist on the system, there is the possibility the system may perform unintended or unauthorized operations. Check_Content Verify all system device files are correctly labeled to prevent unauthorized modification. List all device files on the system that are incorrectly labeled with the following commands: Note: Device files are normally found under "/dev", but applications may place device files in other directories and may necessitate a search of the entire system. # find /dev -context *:device_t:* \( -type c -o -type b \) -printf "%p %Z\n" # find /dev -context *:unlabeled_t:* \( -type c -o -type b \) -printf "%p %Z\n" Note: There are device files, such as "/dev/vmci", that are used when the operating system is a host virtual machine. They will not be owned by a user on the system and require the "device_t" label to operate. These device files are not a finding. If there is output from either of these commands, other than already noted, this is a finding. Fix_Text Restore the SELinux policy for the affected device file from the system policy database using the following command: $ sudo restorecon -v <device_path> Substituting "<device_path>" with the path to the affected device file (from the output of the previous commands). An example device file path would be "/dev/ttyUSB0". If the output of the above command does not indicate that the device was relabeled to a more specific SELinux type label, then the SELinux policy of the system must be updated with more specific policy for the device class specified. If a package was used to install support for a device class, that package could be reinstalled using the following command: $ sudo dnf reinstall <package_name> If a package was not used to install the SELinux policy for a given device class, then it must be generated manually and provide specific type labels. Not_Reviewed Vuln_Num V-282673 Rule_ID SV-282673r1201585_rule Severity medium Rule_Title TOSS 5 /etc/crontab file must have mode 0600. Vuln_Discuss Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations; therefore, service configuration files must have the correct access rights to prevent unauthorized changes. Check_Content Verify the permissions of /etc/crontab using the following command: $ stat -c "%a %n" /etc/crontab 0600 If /etc/crontab does not have a mode of "0600", this is a finding. Fix_Text Configure the TOSS 5 file /etc/crontab with mode "600". $ sudo chmod 0600 /etc/crontab Not_Reviewed Vuln_Num V-282674 Rule_ID SV-282674r1201002_rule Severity medium Rule_Title The TOSS 5 /etc/shadow file must have mode 0000 to prevent unauthorized access. Vuln_Discuss The "/etc/shadow" file contains the list of local system accounts and stores password hashes. Protecting this file is critical for system security. Failure to give ownership of this file to root provides the designated owner with access to sensitive information, which could weaken the system security posture. Check_Content Verify the "/etc/shadow" file has mode "0000" using the following command: $ sudo stat -c "%a %n" /etc/shadow 0 /etc/shadow If a value of "0" is not returned, this is a finding. Fix_Text Change the mode of the file "/etc/shadow" to "0000" using the following command: $ sudo chmod 0000 /etc/shadow Not_Reviewed Vuln_Num V-282675 Rule_ID SV-282675r1201005_rule Severity medium Rule_Title A TOSS 5 firewall must employ a deny-all, allow-by-exception policy for allowing connections to other systems. Vuln_Discuss Failure to restrict network connectivity only to authorized systems permits inbound connections from malicious systems. It also permits outbound connections that may facilitate exfiltration of DOD data. TOSS 5 incorporates the "firewalld" daemon, which allows for many different configurations. One of these configurations is zones. Zones can be used to a deny-all, allow-by-exception approach. The default "drop" zone will drop all incoming network packets unless it is explicitly allowed by the configuration file or is related to an outgoing network connection. Check_Content Verify the TOSS 5 "firewalld" is configured to employ a deny-all, allow-by-exception policy for allowing connections to other systems with the following commands: $ sudo firewall-cmd --state running $ sudo firewall-cmd --get-active-zones public interfaces: ens33 $ sudo firewall-cmd --info-zone=public | grep target target: DROP $ sudo firewall-cmd --permanent --info-zone=public | grep target target: DROP If no zones are active on the TOSS 5 interfaces or if runtime and permanent targets are set to a different option other than "DROP", this is a finding. Fix_Text Configure the "firewalld" daemon to employ a deny-all, allow-by-exception with the following commands: Start by adding the exceptions that are required for mission functionality to the "drop" zone. If SSH access on port 22 is needed, for example, run the following: "sudo firewall-cmd --permanent --add-service=ssh --zone=drop" Reload the firewall rules to update the runtime configuration from the "--permanent" changes made above: $ sudo firewall-cmd --reload Set the default zone to the drop zone: $ sudo firewall-cmd --set-default-zone=drop Note: This is a runtime and permanent change. Add any interfaces to the newly modified "drop" zone: $ sudo firewall-cmd --permanent --zone=drop --change-interface=ens33 Reload the firewall rules for changes to take effect: $ sudo firewall-cmd --reload Not_Reviewed Vuln_Num V-282676 Rule_ID SV-282676r1201008_rule Severity medium Rule_Title TOSS 5 network interfaces must not be in promiscuous mode. Vuln_Discuss Network interfaces in promiscuous mode allow for the capture of all network traffic visible to the system. If unauthorized individuals can access these applications, it may allow them to collect information such as logon IDs, passwords, and key exchanges between systems. If the system is being used to perform a network troubleshooting function, the use of these tools must be documented with the information systems security officer (ISSO) and restricted to only authorized personnel. Check_Content Verify network interfaces are not in promiscuous mode using the following command: $ ip link | grep -i promisc If network interfaces are found on the system in promiscuous mode and their use has not been approved by the ISSO and documented, this is a finding. Fix_Text Configure network interfaces to turn off promiscuous mode unless approved by the ISSO and documented. Set the promiscuous mode of an interface to off using the following command: $ sudo ip link set dev <devicename> multicast off promisc off Not_Reviewed Vuln_Num V-282677 Rule_ID SV-282677r1201330_rule Severity medium Rule_Title TOSS 5 must enable hardening for the Berkeley Packet Filter (BPF) just-in-time (JIT) compiler. Vuln_Discuss When hardened, the extended BPF JIT compiler will randomize any kernel addresses in the BPF programs and maps and will not expose the JIT addresses in "/proc/kallsyms". Check_Content Verify TOSS 5 enables hardening for the BPF JIT with the following commands: $ sudo sysctl net.core.bpf_jit_harden net.core.bpf_jit_harden = 2 If the returned line does not have a value of "2", or a line is not returned, this is a finding. Check that the configuration files are present to enable this kernel parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.core.bpf_jit_harden | tail -1 net.core.bpf_jit_harden = 2 If the network parameter "net.core.bpf_jit_harden" is not equal to "2" or nothing is returned, this is a finding. Fix_Text Configure TOSS 5 to enable hardening for the BPF JIT compiler by adding the following line to a file, in the "/etc/sysctl.d" directory: net.core.bpf_jit_harden = 2 Reload the system configuration files for the changes to take effect. $ sudo sysctl --system Not_Reviewed Vuln_Num V-282678 Rule_ID SV-282678r1201587_rule Severity medium Rule_Title TOSS 5 systems using DNS resolution must have at least two name servers configured. Vuln_Discuss To provide availability for name resolution services, multiple redundant name servers are mandated. A failure in name resolution could lead to the failure of security functions requiring name resolution, which may include time synchronization, centralized authentication, and remote system logging. Check_Content Verify the name servers used by the system using the following command: $ grep nameserver /etc/resolv.conf nameserver 192.168.1.2 nameserver 192.168.1.3 If less than two lines are returned that are not commented out, this is a finding. Fix_Text Configure TOSS 5 to use two or more name servers for DNS resolution based on the DNS mode of the system. If the NetworkManager DNS mode is set to "none", then add the following lines to "/etc/resolv.conf": nameserver [name server 1] nameserver [name server 2] Replace [name server 1] and [name server 2] with the IPs of two different DNS resolvers. If the NetworkManager DNS mode is set to "default" then add two DNS servers to a NetworkManager connection using the following commands: $ sudo nmcli connection modify [connection name] ipv4.dns [name server 1] $ sudo nmcli connection modify [connection name] ipv4.dns [name server 2] Replace [name server 1] and [name server 2] with the IPs of two different DNS resolvers. Replace [connection name] with a valid NetworkManager connection name on the system. Replace ipv4 with ipv6 if IPv6 DNS servers are used. Not_Reviewed Vuln_Num V-282679 Rule_ID SV-282679r1201334_rule Severity medium Rule_Title TOSS 5 must configure a DNS processing mode set in Network Manager. Vuln_Discuss In order to ensure that DNS resolver settings are respected, a DNS mode in Network Manager must be configured. Check_Content Verify TOSS 5 has a DNS mode configured in Network Manager. $ NetworkManager --print-config [main] dns=none If the dns key under main does not exist or is not set to "none" or "default", this is a finding. Fix_Text Configure NetworkManager in TOSS 5 to use a DNS mode. In "/etc/NetworkManager/NetworkManager.conf" add the following line in the "[main]" section: dns = none Reload NetworkManager for the change to take effect. $ sudo systemctl reload NetworkManager Not_Reviewed Vuln_Num V-282680 Rule_ID SV-282680r1201020_rule Severity medium Rule_Title TOSS 5 must not have unauthorized IP tunnels configured. Vuln_Discuss IP tunneling mechanisms can be used to bypass network filtering. If tunneling is required, it must be documented with the information system security officer (ISSO). Check_Content Verify TOSS 5 does not have unauthorized IP tunnels configured. Determine if the "IPsec" service is active using the following command: $ systemctl status ipsec ipsec.service - Internet Key Exchange (IKE) Protocol Daemon for IPsec Loaded: loaded (/usr/lib/systemd/system/ipsec.service; disabled) Active: inactive (dead) If the "IPsec" service is active, check for configured IPsec connections ("conn"), using the following command: $ grep -rni conn /etc/ipsec.conf /etc/ipsec.d/ Verify any returned results are documented with the ISSO. If the IPsec tunnels are active and not approved, this is a finding. Fix_Text Remove all unapproved tunnels from the system or document them with the ISSO. Not_Reviewed Vuln_Num V-282681 Rule_ID SV-282681r1201023_rule Severity medium Rule_Title TOSS 5 must be configured to prevent unrestricted mail relaying. Vuln_Discuss If unrestricted mail relaying is permitted, unauthorized senders could use this host as a mail relay for the purpose of sending spam or other unauthorized activity. Check_Content Verify TOSS 5 is configured to prevent unrestricted mail relaying using the following command: $ postconf -n smtpd_client_restrictions smtpd_client_restrictions = permit_mynetworks,reject If the "smtpd_client_restrictions" parameter contains any entries other than "permit_mynetworks" and "reject", and the additional entries have not been documented with the information system security officer (ISSO), this is a finding. Fix_Text Modify the postfix configuration file to restrict client connections to the local network using the following command: $ sudo postconf -e 'smtpd_client_restrictions = permit_mynetworks,reject' Not_Reviewed Vuln_Num V-282682 Rule_ID SV-282682r1201337_rule Severity high Rule_Title If the Trivial File Transfer Protocol (TFTP) server is required, TOSS 5 TFTP daemon must be configured to operate in secure mode. Vuln_Discuss Restricting TFTP to a specific directory prevents remote users from copying, transferring, or overwriting system files. Using the "-s" option causes the TFTP service to only serve files from the given directory. Check_Content Note: If TFTP is not required, it should not be installed. If TFTP is not installed, this is not applicable. Determine if TFTP server is installed using the following command: $ sudo dnf list installed | grep tftp-server tftp-server.x86_64 x.x-x.el8 Verify the TFTP daemon, if tftp.server is installed, is configured to operate in secure mode using the following command: $ grep -i execstart /usr/lib/systemd/system/tftp.service ExecStart=/usr/sbin/in.tftpd -s /var/lib/tftpboot If TFTP is installed and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Note: The "-s" option ensures that the TFTP server only serves files from the specified directory, which is a security measure to prevent unauthorized access to other parts of the file system. Fix_Text Configure the TFTP daemon to operate in secure mode using the following command: $ sudo systemctl edit tftp.service In the editor, enter: [Service] ExecStart=/usr/sbin/in.tftpd -s /var/lib/tftpboot After making changes, reload the systemd daemon and restart the TFTP service: $ sudo systemctl daemon-reload $ sudo systemctl restart tftp.service Not_Reviewed Vuln_Num V-282683 Rule_ID SV-282683r1201340_rule Severity medium Rule_Title The TOSS 5 libreswan package must be installed. Vuln_Discuss Providing the ability for remote users or systems to initiate a secure VPN connection protects information when it is transmitted over a wide area network. Check_Content Verify the TOSS 5 "libreswan" service package is installed. Check that the "libreswan" service package is installed using the following command: $ sudo dnf list --installed libreswan Example output: libreswan.x86_64 4.6-3.el9 If the "libreswan" package is not installed, this is a finding. Fix_Text Install the "libreswan" service (if it is not already installed) using the following command: $ sudo dnf install libreswan Not_Reviewed Vuln_Num V-282684 Rule_ID SV-282684r1201032_rule Severity high Rule_Title There must be no .shosts files on TOSS 5. Vuln_Discuss The .shosts files are used to configure host-based authentication for individual users or the system via SSH. Host-based authentication is not sufficient for preventing unauthorized access to the system, as it does not require interactive identification and authentication of a connection request, or for the use of two-factor authentication. Check_Content Verify there are no ".shosts" files on TOSS 5 using the following command: $ sudo find / -name .shosts If a ".shosts" file is found, this is a finding. Fix_Text Remove any found ".shosts" files from the system. $ sudo rm /[path]/[to]/[file]/.shosts Not_Reviewed Vuln_Num V-282685 Rule_ID SV-282685r1201035_rule Severity medium Rule_Title TOSS 5 must ignore Internet Protocol version 4 (IPv4) Internet Control Message Protocol (ICMP) redirect messages. Vuln_Discuss ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It should be disabled unless absolutely required. Check_Content Verify TOSS 5 will not accept IPv4 ICMP redirect messages using the following command: $ sudo sysctl net.ipv4.conf.all.accept_redirects net.ipv4.conf.all.accept_redirects = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to ignore IPv4 ICMP redirect messages. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.accept_redirects = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282686 Rule_ID SV-282686r1201038_rule Severity medium Rule_Title TOSS 5 must not forward Internet Protocol version 4 (IPv4) source-routed packets. Vuln_Discuss Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when IPv4 forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It must be disabled unless it is absolutely required. Check_Content Verify TOSS 5 will not accept IPv4 source-routed packets using the following command: $ sudo sysctl net.ipv4.conf.all.accept_source_route net.ipv4.conf.all.accept_source_route = 0 If "net.ipv4.conf.all.accept_source_route" is not set to "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to ignore IPv4 source-routed packets. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.accept_source_route = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282687 Rule_ID SV-282687r1201041_rule Severity medium Rule_Title TOSS 5 must log IPv4 packets with impossible addresses. Vuln_Discuss The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected. Check_Content Verify TOSS 5 logs IPv4 martian packets using the following command: $ sudo sysctl net.ipv4.conf.all.log_martians net.ipv4.conf.all.log_martians = 1 If "net.ipv4.conf.all.log_martians" is not set to "1", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to log martian packets on IPv4 interfaces. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.log_martians=1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282688 Rule_ID SV-282688r1201044_rule Severity medium Rule_Title TOSS 5 must log IPv4 packets with impossible addresses by default. Vuln_Discuss The presence of "martian" packets (which have impossible addresses) as well as spoofed packets, source-routed packets, and redirects could be a sign of nefarious network activity. Logging these packets enables this activity to be detected. Check_Content Verify TOSS 5 logs IPv4 martian packets by default using the following command: $ sudo sysctl net.ipv4.conf.default.log_martians net.ipv4.conf.default.log_martians = 1 If "net.ipv4.conf.default.log_martians" is not set to "1" , or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to log martian packets on IPv4 interfaces by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.log_martians=1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282689 Rule_ID SV-282689r1201344_rule Severity medium Rule_Title TOSS 5 must use reverse path filtering on all IPv4 interfaces. Vuln_Discuss Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface on which they were received. It must not be used on systems that are routers for complicated networks but is helpful for end hosts and routers serving small networks. Check_Content Verify TOSS 5 uses reverse path filtering on all IPv4 interfaces using the following command: $ sudo sysctl net.ipv4.conf.all.rp_filter net.ipv4.conf.all.rp_filter = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to use reverse path filtering on all IPv4 interfaces. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.rp_filter = 1 Reload the system configuration files for the changes to take effect. $ sudo sysctl --system Not_Reviewed Vuln_Num V-282690 Rule_ID SV-282690r1201050_rule Severity medium Rule_Title TOSS 5 must prevent IPv4 Internet Control Message Protocol (ICMP) redirect messages from being accepted. Vuln_Discuss ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. This feature of the IPv4 protocol has few legitimate uses. It must be disabled unless absolutely required. Check_Content Verify TOSS 5 will not accept IPv4 ICMP redirect messages using the following command: $ sudo sysctl net.ipv4.conf.default.accept_redirects net.ipv4.conf.default.accept_redirects = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to prevent IPv4 ICMP redirect messages from being accepted. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.accept_redirects = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282691 Rule_ID SV-282691r1201053_rule Severity medium Rule_Title TOSS 5 must not forward IPv4 source-routed packets by default. Vuln_Discuss Source-routed packets allow the source of the packet to suggest routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. Accepting source-routed packets in the IPv4 protocol has few legitimate uses. It must be disabled unless it is absolutely required, such as when IPv4 forwarding is enabled and the system is legitimately functioning as a router. Check_Content Verify TOSS 5 does not accept IPv4 source-routed packets by default using the following command: $ sudo sysctl net.ipv4.conf.default.accept_source_route net.ipv4.conf.default.accept_source_route = 0 If the returned line does not have a value of "0", a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to not forward IPv4 source-routed packets by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.accept_source_route = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282692 Rule_ID SV-282692r1201056_rule Severity medium Rule_Title TOSS 5 must use a reverse-path filter for IPv4 network traffic when possible by default. Vuln_Discuss Enabling reverse path filtering drops packets with source addresses that should not have been able to be received on the interface on which they were received. It must not be used on systems that are routers for complicated networks but is helpful for end hosts and routers serving small networks. Check_Content Verify TOSS 5 uses reverse path filtering on IPv4 interfaces using the following command: $ sudo sysctl net.ipv4.conf.default.rp_filter net.ipv4.conf.default.rp_filter = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to use reverse path filtering on IPv4 interfaces by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.rp_filter = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282693 Rule_ID SV-282693r1201059_rule Severity medium Rule_Title TOSS 5 must not respond to Internet Control Message Protocol (ICMP) echoes sent to a broadcast address. Vuln_Discuss Responding to broadcast (ICMP) echoes facilitates network mapping and provides a vector for amplification attacks. Ignoring ICMP echo requests (pings) sent to broadcast or multicast addresses makes the system slightly more difficult to enumerate on the network. Check_Content Verify TOSS 5 does not respond to ICMP echoes sent to a broadcast address using the following command: $ sudo sysctl net.ipv4.icmp_echo_ignore_broadcasts net.ipv4.icmp_echo_ignore_broadcasts = 1 If the returned line does not have a value of "1", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|$)' | grep -F net.ipv4.icmp_echo_ignore_broadcasts | tail -1 net.ipv4.icmp_echo_ignore_broadcasts = 1 If "net.ipv4.icmp_echo_ignore_broadcasts" is not set to "1" or is missing, this is a finding. Fix_Text Configure TOSS 5 to not respond to IPv4 ICMP echoes sent to a broadcast address. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.icmp_echo_ignore_broadcasts = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282694 Rule_ID SV-282694r1201062_rule Severity medium Rule_Title TOSS 5 must limit the number of bogus Internet Control Message Protocol (ICMP) response errors logs. Vuln_Discuss Some routers will send responses to broadcast frames that violate RFC-1122, which fills up a log file system with many useless error messages. An attacker may take advantage of this and attempt to flood the logs with bogus error logs. Ignoring bogus ICMP error responses reduces log size, although some activity would not be logged. Check_Content Query the runtime status of the net.ipv4.icmp_ignore_bogus_error_responses kernel parameter using the following command: $ sudo sysctl net.ipv4.icmp_ignore_bogus_error_responses net.ipv4.icmp_ignore_bogus_error_responses = 1 If "net.ipv4.icmp_ignore_bogus_error_responses" is not set to "1", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.icmp_ignore_bogus_error_response | tail -1 net.ipv4.icmp_ignore_bogus_error_response = 1 If "net.ipv4.icmp_ignore_bogus_error_response" is not set to "1" or is missing, this is a finding. Fix_Text Configure TOSS 5 to not log bogus ICMP errors: Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.icmp_ignore_bogus_error_responses = 1 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282695 Rule_ID SV-282695r1201065_rule Severity medium Rule_Title TOSS 5 must not send Internet Control Message Protocol (ICMP) redirects. Vuln_Discuss ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers. Check_Content Verify TOSS 5 does not IPv4 ICMP redirect messages using the following command: $ sudo sysctl net.ipv4.conf.all.send_redirects net.ipv4.conf.all.send_redirects = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to not allow interfaces to perform IPv4 ICMP redirects. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.send_redirects = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282696 Rule_ID SV-282696r1201346_rule Severity medium Rule_Title TOSS 5 must not allow interfaces to perform Internet Control Message Protocol (ICMP) redirects by default. Vuln_Discuss ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages contain information from the system's route table possibly revealing portions of the network topology. The ability to send ICMP redirects is only appropriate for systems acting as routers. Check_Content Verify TOSS 5 does not allow interfaces to perform Internet Protocol version 4 (IPv4) ICMP redirects by default. Check the value of the "default send_redirects" variables using the following command: $ sudo sysctl net.ipv4.conf.default.send_redirects net.ipv4.conf.default.send_redirects=0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Check that the configuration files are present to enable this network parameter. $ sudo /usr/lib/systemd/systemd-sysctl --cat-config | egrep -v '^(#|;)' | grep -F net.ipv4.conf.default.send_redirects | tail -1 net.ipv4.conf.default.send_redirects = 0 If "net.ipv4.conf.default.send_redirects" is not set to "0" and is not documented with the information system security officer (ISSO) as an operational requirement or is missing, this is a finding. Fix_Text Configure TOSS 5 to not allow interfaces to perform IPv4 ICMP redirects by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.default.send_redirects = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282697 Rule_ID SV-282697r1201349_rule Severity medium Rule_Title TOSS 5 must not enable Internet Protocol version 4 (IPv4) packet forwarding unless the system is a router. Vuln_Discuss Routing protocol daemons are typically used on routers to exchange network topology information with other routers. If this capability is used when not required, system network information may be unnecessarily transmitted across the network. Check_Content Verify TOSS 5 is not performing IPv4 packet forwarding unless the system is a router using the following command: $ sudo sysctl net.ipv4.conf.all.forwarding net.ipv4.conf.all.forwarding = 0 If the IPv4 forwarding value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement is missing, this is a finding. Fix_Text Configure TOSS 5 to not allow IPv4 packet forwarding unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv4.conf.all.forwarding = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282698 Rule_ID SV-282698r1201350_rule Severity medium Rule_Title TOSS 5 must not accept router advertisements on all Internet Protocol version 6 (IPv6) interfaces. Vuln_Discuss An illicit router advertisement message could result in a man-in-the-middle attack. Check_Content Verify TOSS 5 does not accept router advertisements on all IPv6 interfaces, unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is not applicable. Determine if router advertisements are not accepted by using the following command: $ sudo sysctl net.ipv6.conf.all.accept_ra net.ipv6.conf.all.accept_ra = 0 If the "accept_ra" value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure TOSS 5 to not accept router advertisements on all IPv6 interfaces unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.accept_ra = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282699 Rule_ID SV-282699r1201351_rule Severity medium Rule_Title TOSS 5 must ignore Internet Protocol version 6 (IPv6) Internet Control Message Protocol (ICMP) redirect messages. Vuln_Discuss An illicit ICMP redirect message could result in a man-in-the-middle attack. Check_Content Verify TOSS 5 ignores IPv6 ICMP redirect messages. Note: If IPv6 is disabled on the system, this requirement is not applicable. Check the value of the "accept_redirects" variables using the following command: $ sysctl net.ipv6.conf.all.accept_redirects net.ipv6.conf.all.accept_redirects = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to ignore IPv6 ICMP redirect messages. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.accept_redirects = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282700 Rule_ID SV-282700r1201352_rule Severity medium Rule_Title TOSS 5 must not forward Internet Protocol version 6 (IPv6) source-routed packets. Vuln_Discuss Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. Check_Content Verify TOSS 5 does not accept IPv6 source-routed packets. Note: If IPv6 is disabled on the system, this requirement is not applicable. Check the value of the accept source route variable using the following command: $ sudo sysctl net.ipv6.conf.all.accept_source_route net.ipv6.conf.all.accept_source_route = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to not forward IPv6 source-routed packets. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.accept_source_route = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282701 Rule_ID SV-282701r1201355_rule Severity medium Rule_Title TOSS 5 must not enable Internet Protocol version 6 (IPv6) packet forwarding unless the system is a router. Vuln_Discuss IP forwarding permits the kernel to forward packets from one network interface to another. The ability to forward packets between two networks is only appropriate for systems acting as routers. Check_Content Verify TOSS 5 is not performing IPv6 packet forwarding unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is not applicable. Check that IPv6 forwarding is disabled using the following commands: $ sudo sysctl net.ipv6.conf.all.forwarding net.ipv6.conf.all.forwarding = 0 If the IPv6 forwarding value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure TOSS 5 to not allow IPv6 packet forwarding unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.all.forwarding = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282702 Rule_ID SV-282702r1201356_rule Severity medium Rule_Title TOSS 5 must not accept router advertisements on all Internet Protocol version 6 (IPv6) interfaces by default. Vuln_Discuss An illicit router advertisement message could result in a man-in-the-middle attack. Check_Content Verify TOSS 5 does not accept router advertisements on all IPv6 interfaces by default, unless the system is a router. Note: If IPv6 is disabled on the system, this requirement is not applicable. Determine if router advertisements are not accepted by default by using the following command: $ sudo sysctl net.ipv6.conf.default.accept_ra net.ipv6.conf.default.accept_ra = 0 If the "accept_ra" value is not "0" and is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure TOSS 5 to not accept router advertisements on all IPv6 interfaces by default unless the system is a router. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.default.accept_ra = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282703 Rule_ID SV-282703r1201358_rule Severity medium Rule_Title TOSS 5 must prevent Internet Protocol version 6 (IPv6) Internet Control Message Protocol (ICMP) redirect messages from being accepted. Vuln_Discuss ICMP redirect messages are used by routers to inform hosts that a more direct route exists for a particular destination. These messages modify the host's route table and are unauthenticated. An illicit ICMP redirect message could result in a man-in-the-middle attack. Check_Content Verify TOSS 5 will not accept IPv6 ICMP redirect messages. Note: If IPv6 is disabled on the system, this requirement is not applicable. Check the value of the default "accept_redirects" variables using the following command: $ sudo sysctl net.ipv6.conf.default.accept_redirects net.ipv6.conf.default.accept_redirects = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to prevent IPv6 ICMP redirect messages from being accepted. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.default.accept_redirects = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282704 Rule_ID SV-282704r1201359_rule Severity medium Rule_Title TOSS 5 must not forward Internet Protocol version 6 (IPv6) source-routed packets by default. Vuln_Discuss Source-routed packets allow the source of the packet to suggest that routers forward the packet along a different path than configured on the router, which can be used to bypass network security measures. This requirement applies only to the forwarding of source-routed traffic, such as when forwarding is enabled and the system is functioning as a router. Accepting source-routed packets in the IPv6 protocol has few legitimate uses. It must be disabled unless it is absolutely required. Check_Content Verify TOSS 5 does not accept IPv6 source-routed packets by default. Note: If IPv6 is disabled on the system, this requirement is not applicable. Check the value of the accept source route variable using the following command: $ sudo sysctl net.ipv6.conf.default.accept_source_route net.ipv6.conf.default.accept_source_route = 0 If the returned line does not have a value of "0", or a line is not returned, this is a finding. Fix_Text Configure TOSS 5 to not forward IPv6 source-routed packets by default. Add or edit the following line in a single system configuration file, in the "/etc/sysctl.d/" directory: net.ipv6.conf.default.accept_source_route = 0 Load settings from all system configuration files using the following command: $ sudo sysctl --system Not_Reviewed Vuln_Num V-282705 Rule_ID SV-282705r1201362_rule Severity medium Rule_Title TOSS 5 must have the openssh-clients package installed. Vuln_Discuss This package includes utilities to make encrypted connections and transfer files securely to SSH servers. Check_Content Verify TOSS 5 has the "openssh-clients" package installed using the following command: $ sudo dnf list --installed openssh-clients Example output: openssh-clients.x86_64 8.7p1-8.el9 If the "openssh-clients" package is not installed, this is a finding. Fix_Text Install the openssh-clients package using the following command: $ sudo dnf install openssh-clients Not_Reviewed Vuln_Num V-282706 Rule_ID SV-282706r1201098_rule Severity medium Rule_Title The TOSS 5 SSH server configuration file must be group-owned by root. Vuln_Discuss Service configuration files enable or disable features of their respective services, which if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes. Check_Content Verify the group ownership of the "/etc/ssh/sshd_config" file using the following command: $ ls -al /etc/ssh/sshd_config rw-------. 1 root root 3669 Feb 22 11:34 /etc/ssh/sshd_config If the "/etc/ssh/sshd_config" file does not have a group owner of "root", this is a finding. Fix_Text Configure the "/etc/ssh/sshd_config" file to be group-owned by root using the following command: $ sudo chgrp root /etc/ssh/sshd_config Not_Reviewed Vuln_Num V-282707 Rule_ID SV-282707r1201101_rule Severity medium Rule_Title The TOSS 5 SSH server configuration file must be owned by root. Vuln_Discuss Service configuration files enable or disable features of their respective services, which if configured incorrectly, can lead to insecure and vulnerable configurations. Therefore, service configuration files must be owned by the correct group to prevent unauthorized changes. Check_Content Verify the ownership of the "/etc/ssh/sshd_config" file using the following command: $ ls -al /etc/ssh/sshd_config rw-------. 1 root root 3669 Feb 22 11:34 /etc/ssh/sshd_config If the "/etc/ssh/sshd_config" file does not have an owner of "root", this is a finding. Fix_Text Configure the "/etc/ssh/sshd_config" file to be owned by root using the following command: $ sudo chown root /etc/ssh/sshd_config Not_Reviewed Vuln_Num V-282708 Rule_ID SV-282708r1201104_rule Severity medium Rule_Title The TOSS 5 SSH server configuration file must have mode 0600 or less permissive. Vuln_Discuss Service configuration files enable or disable features of their respective services that if configured incorrectly can lead to insecure and vulnerable configurations. Therefore, service configuration files should be owned by the correct group to prevent unauthorized changes. Check_Content Verify the permissions of the "/etc/ssh/sshd_config" file using the following command: $ ls -al /etc/ssh/sshd_config rw-------. 1 root root 3669 Feb 22 11:34 /etc/ssh/sshd_config If the "/etc/ssh/sshd_config" permissions are not "0600", this is a finding. Fix_Text Configure the "/etc/ssh/sshd_config" permissions to be "0600" using the following command: $ sudo chmod 0600 /etc/ssh/sshd_config Not_Reviewed Vuln_Num V-282709 Rule_ID SV-282709r1201369_rule Severity medium Rule_Title TOSS 5 SSH private host key files must have mode 0640 or less permissive. Vuln_Discuss If an unauthorized user obtains the private SSH host key file, the host could be impersonated. Check_Content Verify the SSH private host key files have a mode of "0640" or less permissive using the following command: $ ls -l /etc/ssh/*_key 640 /etc/ssh/ssh_host_dsa_key 640 /etc/ssh/ssh_host_ecdsa_key 640 /etc/ssh/ssh_host_ed25519_key 640 /etc/ssh/ssh_host_rsa_key If any private host key file has a mode more permissive than "0640", this is a finding. Fix_Text Configure the mode of SSH private host key files under "/etc/ssh" to "0640" using the following command: $ sudo chmod 0640 /etc/ssh/ssh_host*key Restart the SSH daemon for the changes to take effect. $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282710 Rule_ID SV-282710r1201371_rule Severity medium Rule_Title TOSS 5 SSH public host key files must have mode 0644 or less permissive. Vuln_Discuss If a public host key file is modified by an unauthorized user, the SSH service may be compromised. Check_Content Verify the SSH public host key files have a mode of "0644" or less permissive using the following command: Note: SSH public key files may be found in other directories on the system depending on the installation. $ sudo stat -c "%a %n" /etc/ssh/*.pub 644 /etc/ssh/ssh_host_dsa_key.pub 644 /etc/ssh/ssh_host_ecdsa_key.pub 644 /etc/ssh/ssh_host_ed25519_key.pub 644 /etc/ssh/ssh_host_rsa_key.pub If any key.pub file has a mode more permissive than "0644", this is a finding. Fix_Text Change the mode of public host key files under "/etc/ssh" to "0644" using the following command: $ sudo chmod 0644 /etc/ssh/*key.pub Restart the SSH daemon for the changes to take effect. $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282711 Rule_ID SV-282711r1201373_rule Severity medium Rule_Title The TOSS 5 SSH daemon must not allow rhosts authentication. Vuln_Discuss SSH trust relationships mean a compromise on one host can allow an attacker to move trivially to other hosts. Check_Content Verify the SSH daemon does not allow rhosts authentication using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*ignorerhosts' IgnoreRhosts yes If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding. Fix_Text Configure the SSH daemon to not allow rhosts authentication. Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "yes": IgnoreRhosts yes Restart the SSH service for changes to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282712 Rule_ID SV-282712r1201589_rule Severity medium Rule_Title The TOSS 5 SSH daemon must not allow known hosts authentication. Vuln_Discuss Configuring the IgnoreUserKnownHosts setting for the SSH daemon provides additional assurance that remote login via SSH will require a password, even in the event of misconfiguration elsewhere. Check_Content Verify the SSH daemon does not allow known hosts authentication using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*ignoreuserknownhosts' IgnoreUserKnownHosts yes If the value is returned as "no", the returned line is commented out, or no output is returned, this is a finding. Fix_Text Configure the SSH daemon to not allow known hosts authentication. Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "yes": IgnoreUserKnownHosts yes Restart the SSH service for changes to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282713 Rule_ID SV-282713r1201377_rule Severity medium Rule_Title The TOSS 5 SSH daemon must perform strict mode checking of home directory configuration files. Vuln_Discuss If other users have access to modify user-specific SSH configuration files, they may be able to log into the system as another user. Check_Content Verify the SSH daemon performs strict mode checking of home directory configuration files using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*strictmodes' StrictModes yes If the "StrictModes" keyword is set to "no", the returned line is commented out, or no output is returned, this is a finding. Fix_Text Configure the SSH daemon to perform strict mode checking of home directory configuration files. Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "yes": StrictModes yes Restart the SSH service for changes to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282714 Rule_ID SV-282714r1201379_rule Severity medium Rule_Title The TOSS 5 SSH daemon must display the date and time of the last successful account logon upon an SSH logon. Vuln_Discuss Providing users feedback on when account accesses last occurred facilitates user recognition and reporting of unauthorized account use. Check_Content Verify the SSH daemon provides users with feedback on when account accesses last occurred using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*printlastlog' PrintLastLog yes If the "PrintLastLog" keyword is set to "no", the returned line is commented out, or no output is returned, this is a finding. Fix_Text Configure the SSH daemon to provide users with feedback on when account accesses last occurred. Add the following line in "/etc/ssh/sshd_config" or uncomment the line and set the value to "yes": PrintLastLog yes Restart the SSH service for changes to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282715 Rule_ID SV-282715r1201125_rule Severity medium Rule_Title The TOSS 5 effective dconf policy must match the policy keyfiles. Vuln_Discuss Unlike text-based keyfiles, the binary database is impossible to check through most automated and all manual means; therefore, to evaluate dconf configuration, both have to be true at the same time—configuration files have to be compliant, and the database needs to be more recent than those keyfiles, which gives confidence that it reflects them. Check_Content Check the last modification time of the local databases, comparing it to the last modification time of the related keyfiles. The following command will check every dconf database and compare its modification time to the related system keyfiles: Note: This requirement assumes the use of the TOSS 5 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is not applicable. $ function dconf_needs_update { for db in $(find /etc/dconf/db -maxdepth 1 -type f); do db_mtime=$(stat -c %Y "$db"); keyfile_mtime=$(stat -c %Y "$db".d/* | sort -n | tail -1); if [ -n "$db_mtime" ] && [ -n "$keyfile_mtime" ] && [ "$db_mtime" -lt "$keyfile_mtime" ]; then echo "$db needs update"; return 1; fi; done; }; dconf_needs_update If the command has any output, then a dconf database needs to be updated, and this is a finding. Fix_Text Update the dconf databases using the following command: $ sudo dconf update Not_Reviewed Vuln_Num V-282716 Rule_ID SV-282716r1201128_rule Severity medium Rule_Title TOSS 5 must disable the ability of a user to restart the system from the login screen. Vuln_Discuss A user who is at the console can reboot the system at the login screen. If restart or shutdown buttons are pressed at the login screen, this can create the risk of short-term loss of availability of systems due to reboot. Check_Content Verify TOSS 5 disables a user's ability to restart the system using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is not applicable. $ grep -R disable-restart-buttons /etc/dconf/db/* /etc/dconf/db/distro.d/20-authselect:disable-restart-buttons='true' If the "disable-restart-button" setting is not set to "true", is missing or commented out from the dconf database files, this is a finding. Fix_Text Configure TOSS 5 to disable a user's ability to restart the system. Add or update the [org/gnome/settings-daemon/] section of the /etc/dconf/db/local.d/00-security-settings" database file and add or update the following lines: [org/gnome/login-screen] disable-restart-buttons='true' Then update the dconf system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282717 Rule_ID SV-282717r1201644_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the disable-restart-buttons setting for the graphical user interface. Vuln_Discuss A user who is at the console can reboot the system at the login screen. If restart or shutdown buttons are pressed at the login screen, this can create the risk of short-term loss of availability of systems due to reboot. Check_Content Verify TOSS 5 prevents a user from overriding the disable-restart-buttons setting for graphical user interfaces. Note: This requirement assumes the use of the TOSS 5 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is not applicable. Determine which profile the system database is using the following command: $ sudo grep system-db /etc/dconf/profile/user system-db:local Check that graphical settings are locked from nonprivileged user modification using the following command: Note: The example below is using the database "local" for the system, so the path is "/etc/dconf/db/local.d". This path must be modified if a database other than "local" is being used. $ grep disable-restart-buttons /etc/dconf/db/local.d/locks/* /org/gnome/login-screen/disable-restart-buttons If the command does not return at least the example result, this is a finding. Fix_Text Configure TOSS 5 to prevent a user from overriding the disable-restart-buttons setting for graphical user interfaces. Create a database to contain the systemwide graphical user logon settings (if it does not already exist) using the following command: $ sudo touch /etc/dconf/db/local.d/locks/session Add the following line to prevent nonprivileged users from modifying it: /org/gnome/login-screen/disable-restart-buttons Run the following command to update the database: $ sudo dconf update Not_Reviewed Vuln_Num V-282718 Rule_ID SV-282718r1201134_rule Severity medium Rule_Title TOSS 5 must disable the ability of a user to accidentally press Ctrl-Alt-Del and cause a system to shut down or reboot. Vuln_Discuss A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. Check_Content Verify TOSS 5 is configured to ignore the Ctrl-Alt-Del sequence in the GNOME desktop using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is not applicable. $ gsettings get org.gnome.settings-daemon.plugins.media-keys logout "['']" If the GNOME desktop is configured to shut down when Ctrl-Alt-Del is pressed, this is a finding. Fix_Text Configure TOSS 5 to ignore the Ctrl-Alt-Del sequence in the GNOME desktop. Add or update the [org/gnome/settings-daemon/plugins/media-keys] section of the /etc/dconf/db/local.d/00-security-settings database file and add or update the following lines: [org/gnome/settings-daemon/plugins/media-keys] logout=[''] Run the following command to update the database: $ sudo dconf update Not_Reviewed Vuln_Num V-282719 Rule_ID SV-282719r1201137_rule Severity medium Rule_Title TOSS 5 must prevent a user from overriding the Ctrl-Alt-Del sequence settings for the graphical user interface. Vuln_Discuss A locally logged-in user who presses Ctrl-Alt-Del, when at the console, can reboot the system. If accidentally pressed, as could happen in the case of mixed OS environment, this can create the risk of short-term loss of availability of systems due to unintentional reboot. Check_Content Verify users cannot enable the Ctrl-Alt-Del sequence in the GNOME desktop using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is not applicable. $ grep logout /etc/dconf/db/local.d/locks/* /org/gnome/settings-daemon/plugins/media-keys/logout If the output is not "/org/gnome/settings-daemon/plugins/media-keys/logout", the line is commented out, or the line is missing, this is a finding. Fix_Text Configure TOSS 5 to disallow the user changing the Ctrl-Alt-Del sequence in the GNOME desktop. Create a database to container systemwide graphical user logon settings (if it does not already exist) using the following command: $ sudo touch /etc/dconf/db/local.d/locks/session Add the following line to the session locks file to prevent nonprivileged users from modifying the Ctrl-Alt-Del setting: /org/gnome/settings-daemon/plugins/media-keys/logout Run the following command to update the database: $ sudo dconf update Not_Reviewed Vuln_Num V-282720 Rule_ID SV-282720r1201591_rule Severity medium Rule_Title TOSS 5 must disable the user list at logon for graphical user interfaces. Vuln_Discuss Leaving the user list enabled is a security risk since it allows anyone with physical access to the system to enumerate known user accounts without authenticated access to the system. Check_Content Verify TOSS 5 disables the user logon list for graphical user interfaces using the following command: Note: This requirement assumes the use of the TOSS 5 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is not applicable. $ sudo gsettings get org.gnome.login-screen disable-user-list true If the setting is "false", this is a finding. Fix_Text Configure TOSS 5 to disable the user list at logon for graphical user interfaces. Create a database to contain the systemwide screensaver settings (if it does not already exist) using the following command: Note: The example below is using the database "local" for the system, so if the system is using another database in "/etc/dconf/profile/user", the file should be created under the appropriate subdirectory. $ sudo touch /etc/dconf/db/local.d/02-login-screen [org/gnome/login-screen] disable-user-list=true Update the system databases: $ sudo dconf update Not_Reviewed Vuln_Num V-282721 Rule_ID SV-282721r1201143_rule Severity medium Rule_Title All TOSS 5 local interactive user accounts must be assigned a home directory upon creation. Vuln_Discuss If local interactive users are not assigned a valid home directory, there is no place for the storage and control of files they should own. Check_Content Verify all local interactive users on TOSS 5 are assigned a home directory upon creation using the following command: $ grep -i create_home /etc/login.defs CREATE_HOME yes If the value for "CREATE_HOME" parameter is not set to "yes", the line is missing, or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to assign home directories to all new local interactive users by setting the "CREATE_HOME" parameter in "/etc/login.defs" to "yes" as follows. CREATE_HOME yes Not_Reviewed Vuln_Num V-282722 Rule_ID SV-282722r1201146_rule Severity medium Rule_Title TOSS 5 must set the umask value to 077 for all local interactive user accounts. Vuln_Discuss The umask controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although umask can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. Check_Content Verify the default umask for all local interactive users is "077". Identify the locations of all local interactive user home directories in the "/etc/passwd" file. Check all local interactive user initialization files for interactive users using the following command. Note: The example is for a system that is configured to create users home directories in the "/home" directory. # grep -ri umask /home/ /home/wadea/.bash_history:grep -i umask /etc/bashrc /etc/csh.cshrc /etc/profile /home/wadea/.bash_history:grep -i umask /etc/login.defs If any local interactive user initialization files are found to have a umask statement that sets a value less restrictive than "077", this is a finding. Fix_Text Remove the umask statement from all local interactive user's initialization files. If the account is for an application, the requirement for a umask less restrictive than "077" can be documented with the information system security officer, but the user agreement for access to the account must specify that the local interactive user must log on to their account first and then switch the user to the application account with the correct option to gain the account's environment variables. Not_Reviewed Vuln_Num V-282723 Rule_ID SV-282723r1201149_rule Severity medium Rule_Title TOSS 5 system accounts must not have an interactive login shell. Vuln_Discuss Ensuring shells are not given to system accounts upon login makes it more difficult for attackers to make use of system accounts. Check_Content Verify system accounts must not have an interactive login shell using the following command: $ awk -F: '($3<1000){print $1 ":" $3 ":" $7}' /etc/passwd root:0:/bin/bash bin:1:/sbin/nologin daemon:2:/sbin/nologin adm:3:/sbin/nologin lp:4:/sbin/nologin Identify the system accounts from this listing that do not have a nologin or similar noninteractive shell. If any system account (other than the root account) has a login shell and it is not documented with the information system security officer (ISSO), this is a finding. Fix_Text Configure TOSS 5 so that all noninteractive accounts on the system do not have an interactive shell assigned to them. If the system account needs a shell assigned for mission operations, document the need with the information system security officer (ISSO). Run the following command to disable the interactive shell for a specific noninteractive user account: Replace <user> with the user that has a login shell. $ sudo usermod --shell /sbin/nologin <user> Do not perform the steps in this section on the root account. Doing so will cause the system to become inaccessible. Not_Reviewed Vuln_Num V-282724 Rule_ID SV-282724r1201152_rule Severity medium Rule_Title Executable search paths within the initialization files of all local interactive TOSS 5 users must only contain paths that resolve to the system default or the users home directory. Vuln_Discuss The executable search path (typically the PATH environment variable) contains a list of directories for the shell to search to find executables. If this path includes the current working directory (other than the user's home directory), executables in these directories may be executed instead of system commands. This variable is formatted as a colon-separated list of directories. If there is an empty entry, such as a leading or trailing colon or two consecutive colons, this is interpreted as the current working directory. If deviations from the default system search path for the local interactive user are required, they must be documented with the information system security officer (ISSO). Check_Content Verify all local interactive user initialization file executable search path statements do not contain statements that will reference a working directory other than user home directories with the following commands: $ sudo grep -i path= /home/*/.* /home/[localinteractiveuser]/.bash_profile:PATH=$PATH:$HOME/.local/bin:$HOME/bin If any local interactive user initialization files have executable search path statements that include directories outside of their home directory and is not documented with the ISSO as an operational requirement, this is a finding. Fix_Text Edit the local interactive user initialization files to change any PATH variable statements that reference directories other than their home directory. If a local interactive user requires path variables to reference a directory owned by the application, it must be documented with the ISSO. Not_Reviewed Vuln_Num V-282725 Rule_ID SV-282725r1201593_rule Severity medium Rule_Title All TOSS 5 local interactive users must have a home directory assigned in the /etc/passwd file. Vuln_Discuss If local interactive users are not assigned a valid home directory, there is no place to store and control the files they should own. Check_Content Verify interactive users on the system have a home directory assigned using the following command: $ sudo awk -F: '($3>=1000)&&($7 !~ /nologin/){print $1, $3, $6}' /etc/passwd smithk:x:1000:1000:smithk:/home/smithk:/bin/bash scsaustin:x:1001:1001:scsaustin:/home/scsaustin:/bin/bash djohnson:x:1002:1002:djohnson:/home/djohnson:/bin/bash Inspect the output and verify that all interactive users (normally users with a user identifier [UID] greater than 1000) have a home directory defined. If users home directory is not defined, this is a finding. Fix_Text Create and assign home directories to all local interactive users on TOSS 5 that currently do not have a home directory assigned. Not_Reviewed Vuln_Num V-282726 Rule_ID SV-282726r1201158_rule Severity medium Rule_Title All TOSS 5 local interactive user home directories defined in the /etc/passwd file must exist. Vuln_Discuss If a local interactive user has a home directory defined that does not exist, the user may be given access to the / directory as the current working directory upon logon. This could create a denial of service because the user would not be able to access their logon configuration files, and it may give them visibility to system files they normally would not be able to access. Check_Content Verify the assigned home directories of all interactive users on the system exist using the following command: $ sudo pwck -r user 'mailnull': directory 'var/spool/mqueue' does not exist The output should not return any interactive users. If the user's home directory does not exist, this is a finding. Fix_Text Create home directories to all local interactive users that currently do not have a home directory assigned. Use the following commands to create the user home directory assigned in "/etc/ passwd": Note: The example will be for the user "wadea", who has a home directory of "/home/wadea", a user identifier (UID) of "wadea", and a Group Identifier (GID) of "users assigned" in "/etc/passwd". $ sudo mkdir /home/wadea $ sudo chown wadea /home/wadea $ sudo chgrp users /home/wadea $ sudo chmod 0750 /home/wadea Not_Reviewed Vuln_Num V-282727 Rule_ID SV-282727r1201161_rule Severity medium Rule_Title All TOSS 5 local interactive user home directories must be group-owned by the home directory owner's primary group. Vuln_Discuss If the Group Identifier (GID) of a local interactive user's home directory is not the same as the primary GID of the user, this would allow unauthorized access to the user's files, and users that share the same group may not be able to access files that they legitimately should. Check_Content Verify the assigned home directory of all local interactive users is group owned by that user's primary GID using the following command. Note: This may miss local interactive users that have been assigned a privileged user identifier (UID). Evidence of interactive use may be obtained from a number of log files containing system logon information. The returned directory "/home/wadea" is used as an example. $ sudo ls -ld $(awk -F: '($3>=1000)&&($7 !~ /nologin/){print $6}' /etc/passwd) drwxr-x--- 2 wadea admin 4096 Jun 5 12:41 wadea Check the user's primary group using the following command: $ sudo grep $(grep wadea /etc/passwd | awk -F: ‘{print $4}') /etc/group admin:x:250:wadea,jonesj,jacksons If the user home directory referenced in "/etc/passwd" is not group-owned by that user's primary GID, this is a finding. Fix_Text Change the group owner of a local interactive user's home directory to the group found in "/etc/passwd". To change the group owner of a local interactive user's home directory, use the following command: Note: The example will be for the user "wadea", who has a home directory of "/home/wadea", and has a primary group of users. $ sudo chgrp users /home/wadea Not_Reviewed Vuln_Num V-282728 Rule_ID SV-282728r1201164_rule Severity medium Rule_Title TOSS 5 must not have unauthorized accounts. Vuln_Discuss Accounts providing no operational purpose provide additional opportunities for system compromise. Unnecessary accounts include user accounts for individuals not requiring access to the system and application accounts for applications not installed on the system. Check_Content Verify there are no unauthorized interactive user accounts using the following command: $ less /etc/passwd root:x:0:0:root:/root:/bin/bash ... games:x:12:100:games:/usr/games:/sbin/nologin scsaustin:x:1001:1001:scsaustin:/home/scsaustin:/bin/bash djohnson:x:1002:1002:djohnson:/home/djohnson:/bin/bash Interactive user account, generally will have a user identifier (UID) of 1000 or greater, a home directory in a specific partition, and an interactive shell. Obtain the list of interactive user accounts authorized to be on the system from the system administrator (SA) or information system security officer (ISSO) and compare it to the list of local interactive user accounts on the system. If there are unauthorized local user accounts on the system, this is a finding. Fix_Text Remove unauthorized local interactive user accounts with the following command where <unauthorized_user> is the unauthorized account: $ sudo userdel <unauthorized_user> Not_Reviewed Vuln_Num V-282729 Rule_ID SV-282729r1201167_rule Severity high Rule_Title The root account must be the only account with unrestricted access to TOSS 5 system. Vuln_Discuss An account has root authority if it has a user identifier (UID) of "0". Multiple accounts with a UID of "0" afford more opportunity for potential intruders to guess a password for a privileged account. Properly configuring sudo is recommended to afford multiple system administrators (SAs) access to root privileges in an accountable manner. Check_Content Verify only the "root" account has a UID "0" assignment using the following command: $ awk -F: '$3 == 0 {print $1}' /etc/passwd root If any accounts other than "root" have a UID of "0", this is a finding. Fix_Text Change the UID of any account on the system, other than root, that has a UID of "0". If the account is associated with system commands or applications, the UID should be changed to one greater than "0" but less than "1000". Otherwise, assign a UID of greater than "1000" that has not already been assigned. Not_Reviewed Vuln_Num V-282730 Rule_ID SV-282730r1201170_rule Severity medium Rule_Title Local TOSS 5 initialization files must not execute world-writable programs. Vuln_Discuss If user start-up files execute world-writable programs, especially in unprotected directories, they could be maliciously modified to destroy user files or otherwise compromise the system at the user level. If the system is compromised at the user level, it is easier to elevate privileges to eventually compromise the system at the root and network level. Check_Content Verify local initialization files do not execute world-writable programs using the following command. Note: The example will be for a system that is configured to create user home directories in the "/home" directory. $ sudo find /home -perm -002 -type f -name ".[^.]*" -exec ls -ld {} \; If any local initialization files are found to reference world-writable files, this is a finding. Fix_Text Set the mode on files being executed by the local initialization files using the following command: $ sudo chmod 0755 <file> Not_Reviewed Vuln_Num V-282731 Rule_ID SV-282731r1201173_rule Severity low Rule_Title TOSS 5 must display the date and time of the last successful account logon upon user logon. Vuln_Discuss Users must be aware of activity that occurs regarding their account. Providing users with information regarding the number of unsuccessful attempts that were made to login to their account allows the user to determine if any unauthorized activity has occurred and gives them an opportunity to notify administrators. Check_Content Verify users are provided with feedback on when account accesses last occurred using the following command: $ sudo grep pam_lastlog /etc/pam.d/postlogin session required pam_lastlog.so showfailed If "pam_lastlog" is missing from "/etc/pam.d/postlogin" file, or the silent option is present, this is a finding. Fix_Text Configure TOSS 5 to provide users with feedback on when account accesses last occurred by setting the required configuration options in "/etc/pam.d/postlogin". Add the following line to the top of "/etc/pam.d/postlogin": session required pam_lastlog.so showfailed Not_Reviewed Vuln_Num V-282732 Rule_ID SV-282732r1201176_rule Severity medium Rule_Title TOSS 5 must have policycoreutils package installed. Vuln_Discuss If security functions are not verified, they may not operate correctly and the failure may go unnoticed. Security function is defined as the hardware, software, and/or firmware of the information system responsible for enforcing the system security policy and supporting the isolation of code and data on which the protection is based. Security functionality includes, but is not limited to, establishing system accounts, configuring access authorizations (i.e., permissions, privileges), setting events to be audited, and setting intrusion detection parameters. "policycoreutils" contains the policy core utilities that are required for basic operation of an SELinux-enabled system. These utilities include "load_policy" to load SELinux policies, "setfile" to label filesystems, "newrole" to switch roles, and "run_init" to run "/etc/init.d" scripts in the proper context. Check_Content Verify the TOSS 5 "policycoreutils" package is installed using the following command: $ sudo dnf list --installed policycoreutils Example output: policycoreutils.x86_64 3.3-6.el9_0 If the "policycoreutils" package is not installed, this is a finding. Fix_Text Install the "policycoreutils" package using the following command: $ sudo dnf install policycoreutils Not_Reviewed Vuln_Num V-282733 Rule_ID SV-282733r1201179_rule Severity medium Rule_Title TOSS 5 policycoreutils-python-utils package must be installed. Vuln_Discuss The "policycoreutils-python-utils" package is required to operate and manage an SELinux environment and its policies. It provides utilities such as "semanage", "audit2allow", "audit2why", "chcat", and "sandbox". Check_Content Verify the TOSS 5 "policycoreutils-python-utils" service package is installed using the following command: $ sudo dnf list --installed policycoreutils-python-utils Example output: policycoreutils-python-utils.noarch 3.3-6.el9_0 If the "policycoreutils-python-utils" package is not installed, this is a finding. Fix_Text Install the "policycoreutils-python-utils" service package using the following command: $ sudo dnf install policycoreutils-python-utils Not_Reviewed Vuln_Num V-282734 Rule_ID SV-282734r1201182_rule Severity medium Rule_Title TOSS 5 must require reauthentication when using the sudo command. Vuln_Discuss Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical that the organization requires the user to reauthenticate when using the "sudo" command. If the value is set to an integer less than "0", the user's time stamp will not expire and the user will not have to reauthenticate for privileged actions until the user's session is terminated. Check_Content Verify TOSS 5 requires reauthentication when using the "sudo" command to elevate privileges using the following command: $ sudo grep -ir 'timestamp_timeout' /etc/sudoers /etc/sudoers.d/* /etc/sudoers:Defaults timestamp_timeout=0 If results are returned from more than one file location, this is a finding. If "timestamp_timeout" is set to a negative number, is commented out, or no results are returned, this is a finding. Fix_Text Configure TOSS 5 to reauthenticate "sudo" commands after the specified timeout. Add the following line to "/etc/sudoers": Defaults timestamp_timeout=0 Not_Reviewed Vuln_Num V-282735 Rule_ID SV-282735r1201185_rule Severity medium Rule_Title TOSS 5 must require users to reauthenticate for privilege escalation. Vuln_Discuss Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical that the user reauthenticate. Check_Content Verify "/etc/sudoers" has no occurrences of "!authenticate" using the following command: $ sudo grep -ir '!authenticate' /etc/sudoers /etc/sudoers.d/* If any occurrences of "!authenticate" are returned, this is a finding. Fix_Text Configure TOSS 5 to not allow users to execute privileged actions without authenticating. Remove any occurrence of "!authenticate" found in "/etc/sudoers" file or files in the "/etc/sudoers.d" directory: $ sudo sed -i '/\!authenticate/ s/^/# /g' /etc/sudoers /etc/sudoers.d/* Not_Reviewed Vuln_Num V-282736 Rule_ID SV-282736r1201188_rule Severity medium Rule_Title TOSS 5 must restrict privilege elevation to authorized personnel. Vuln_Discuss If the "sudoers" file is not configured correctly, any user defined on the system can initiate privileged actions on the target system. Check_Content Verify TOSS 5 restricts privilege elevation to authorized personnel using the following command: $ sudo sh -c 'grep -iw ALL /etc/sudoers /etc/sudoers.d/*' If the either of the following entries are returned, this is a finding: ALL ALL=(ALL) ALL ALL ALL=(ALL:ALL) ALL Fix_Text Remove the following entries from the /etc/sudoers file or configuration file under /etc/sudoers.d/: ALL ALL=(ALL) ALL ALL ALL=(ALL:ALL) ALL Not_Reviewed Vuln_Num V-282737 Rule_ID SV-282737r1201191_rule Severity high Rule_Title TOSS 5 must not allow blank or null passwords. Vuln_Discuss If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. Check_Content Verify null passwords cannot be used by running the following command: $ sudo grep -i nullok /etc/pam.d/system-auth /etc/pam.d/password-auth If an output is produced, this is a finding. Fix_Text Remove any instances of the "nullok" option in the "/etc/pam.d/password-auth" and "/etc/pam.d/system-auth" files to prevent logons with empty passwords. Note: Manual changes to the listed file may be overwritten by the "authselect" program. Not_Reviewed Vuln_Num V-282738 Rule_ID SV-282738r1201194_rule Severity high Rule_Title TOSS 5 must ensure the password complexity module is enabled in the system-auth file. Vuln_Discuss Enabling PAM password complexity permits enforcement of strong passwords and consequently makes the system less prone to dictionary attacks. Check_Content Verify TOSS 5 uses "pwquality" to enforce the password complexity rules in the "system-auth" file using the following command: $ cat /etc/pam.d/system-auth | grep pam_pwquality password required pam_pwquality.so If the command does not return a line containing the value "pam_pwquality.so", or the line is commented out, this is a finding. Fix_Text Configure TOSS 5 to use "pwquality" to enforce password complexity rules. Add the following line to the "/etc/pam.d/system-auth" file(or modify the line to have the required value): password required pam_pwquality.so Not_Reviewed Vuln_Num V-282739 Rule_ID SV-282739r1201595_rule Severity medium Rule_Title TOSS 5 must require users to provide a password for privilege escalation. Vuln_Discuss Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical that the user reauthenticate. Check_Content Verify "/etc/sudoers" has no occurrences of "NOPASSWD" using the following command: $ sudo grep -ri nopasswd /etc/sudoers /etc/sudoers.d/* If any occurrences of "NOPASSWD" are returned and this is not documented with the information system security officer (ISSO) as an operational requirement, this is a finding. Fix_Text Configure TOSS 5 to not allow users to execute privileged actions without authenticating with a password. Remove any occurrence of "NOPASSWD" found in "/etc/sudoers" file or files in the "/etc/sudoers.d" directory. $ sudo sed -i '/NOPASSWD/ s/^/# /g' /etc/sudoers /etc/sudoers.d/* Not_Reviewed Vuln_Num V-282740 Rule_ID SV-282740r1201200_rule Severity medium Rule_Title TOSS 5 must not be configured to bypass password requirements for privilege escalation. Vuln_Discuss Without reauthentication, users may access resources or perform tasks for which they do not have authorization. When operating systems provide the capability to escalate a functional capability, it is critical that the user reauthenticate. Check_Content Verify TOSS 5 is not configured to bypass password requirements for privilege escalation using the following command: $ sudo grep pam_succeed_if /etc/pam.d/sudo If any occurrences of " pam_succeed_if " are returned, this is a finding. Fix_Text Configure TOSS 5 to require users to supply a password for privilege escalation. Remove any occurrences of " pam_succeed_if " in the "/etc/pam.d/sudo" file. Not_Reviewed Vuln_Num V-282741 Rule_ID SV-282741r1201203_rule Severity medium Rule_Title TOSS 5 must not have accounts configured with blank or null passwords. Vuln_Discuss If an account has an empty password, anyone could log in and run commands with the privileges of that account. Accounts with empty passwords should never be used in operational environments. Check_Content Verify null or blank passwords cannot be used using the following command: $ sudo awk -F: '!$2 {print $1}' /etc/shadow If the command returns any results, this is a finding. Fix_Text Configure all accounts on TOSS 5 to have a password or lock the account using the following commands: Perform a password reset: $ sudo passwd [username] To lock an account: $ sudo passwd -l [username] Not_Reviewed Vuln_Num V-282742 Rule_ID SV-282742r1201206_rule Severity medium Rule_Title TOSS 5 must use a file integrity tool that is configured to use FIPS 140-3-approved cryptographic hashes for validating file contents and directories. Vuln_Discuss TOSS 5 installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory. File integrity tools use cryptographic hashes for verifying file contents and directories have not been altered. These hashes must be 140-3-approved cryptographic hashes. Satisfies: SRG-OS-000480-GPOS-00227, SRG-OS-000550-GPOS-00100 Check_Content Verify AIDE is configured to use FIPS 140-3 file hashing using the following command: $ grep sha512 /etc/aide.conf All=p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux If the "sha512" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or another file integrity tool is not using 140-3-approved cryptographic hashes for validating file contents and directories, this is a finding. Fix_Text Configure the file integrity tool to use FIPS 140-3 cryptographic hashes for validating file and directory contents. If AIDE is installed, ensure the "sha512" rule is present on all uncommented file and directory selection lists. Exclude any log files or files expected to change frequently to reduce unnecessary notifications. Not_Reviewed Vuln_Num V-282743 Rule_ID SV-282743r1201209_rule Severity low Rule_Title TOSS 5 must be configured so that the file integrity tool verifies Access Control Lists (ACLs). Vuln_Discuss TOSS 5 installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory. ACLs can provide permissions beyond those permitted through the file mode and must be verified by the file integrity tools. Check_Content Confirm AIDE is verifying ACLs using the following command: $ grep acl /etc/aide.conf All= p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux If the "acl" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or ACLs are not being checked by another file integrity tool, this is a finding. Fix_Text Configure the file integrity tool to check file and directory ACLs. If AIDE is installed, ensure the "acl" rule is present on all uncommented file and directory selection lists. Not_Reviewed Vuln_Num V-282744 Rule_ID SV-282744r1201212_rule Severity low Rule_Title TOSS 5 must be configured so the file integrity tool verifies extended attributes. Vuln_Discuss TOSS 5 installation media ships with an optional file integrity tool called Advanced Intrusion Detection Environment (AIDE). AIDE is highly configurable at install time. This requirement assumes the "aide.conf" file is under the "/etc" directory. Extended attributes in file systems are used to contain arbitrary data and file metadata with security implications. Check_Content Verify AIDE is configured to verify extended attributes using the following command: $ grep xattrs /etc/aide.conf All= p+i+n+u+g+s+m+S+sha512+acl+xattrs+selinux If the "xattrs" rule is not being used on all uncommented selection lines in the "/etc/aide.conf" file, or extended attributes are not being checked by another file integrity tool, this is a finding. Fix_Text Configure the file integrity tool to check file and directory extended attributes. If AIDE is installed, ensure the "xattrs" rule is present on all uncommented file and directory selection lists. Not_Reviewed Vuln_Num V-282745 Rule_ID SV-282745r1201645_rule Severity medium Rule_Title TOSS 5 must have the packages required for encrypting off-loaded audit logs installed. Vuln_Discuss The "rsyslog-gnutls" package provides Transport Layer Security (TLS) support for the rsyslog daemon, which enables secure remote logging. Check_Content Verify TOSS 5 has the "rsyslog-gnutls" package installed using the following command: $ sudo dnf list --installed rsyslog-gnutls Example output: rsyslog-gnutls.x86_64 8.2102.0-101.el9_0.1 If the "rsyslog-gnutls" package is not installed, this is a finding. Fix_Text Install the "rsyslog-gnutls" package using the following command: $ sudo dnf install rsyslog-gnutls Not_Reviewed Vuln_Num V-282746 Rule_ID SV-282746r1201218_rule Severity medium Rule_Title The rsyslog service on TOSS 5 must be active. Vuln_Discuss The "rsyslog" service must be running to provide logging services, which are essential to system administration. Check_Content Verify "rsyslog" is active using the following command: $ systemctl is-active rsyslog active If the "rsyslog" service is not active, this is a finding. Fix_Text To enable the rsyslog service, run the following command: $ sudo systemctl enable --now rsyslog Not_Reviewed Vuln_Num V-282747 Rule_ID SV-282747r1201386_rule Severity medium Rule_Title TOSS 5 must be configured so the rsyslog daemon does not accept log messages from other servers unless the server is being used for log aggregation. Vuln_Discuss Unintentionally running an rsyslog server that accepts remote messages puts the system at increased risk. Malicious rsyslog messages sent to the server could exploit vulnerabilities in the server software itself, could introduce misleading information into the system's logs, or could fill the system's storage, leading to a denial of service. If the system is intended to be a log aggregation server, its use must be documented with the information system security officer (ISSO). Check_Content Verify TOSS 5 is not configured to receive remote logs using rsyslog with the following commands: $ grep -i modload /etc/rsyslog.conf /etc/rsyslog.d/* $ModLoad imtcp $ModLoad imrelp $ grep -i serverrun /etc/rsyslog.conf /etc/rsyslog.d/* $InputTCPServerRun 514 $InputRELPServerRun 514 Note: An error about no files or directories may be returned. This is not a finding. If any lines are returned by the command, then rsyslog is configured to receive remote messages, and this is a finding. Fix_Text Configure TOSS 5 to not receive remote logs using rsyslog. Remove the lines in "/etc/rsyslog.conf" and any files in the "/etc/rsyslog.d" directory that match any of the following: $ModLoad imtcp $ModLoad imudp $ModLoad imrelp $InputTCPServerRun [0-9]* $UDPServerRun [0-9]* $InputRELPServerRun [0-9]* Restart the rsyslog daemon for the changes to take effect. $ sudo systemctl restart rsyslog.service Not_Reviewed Vuln_Num V-282748 Rule_ID SV-282748r1201388_rule Severity medium Rule_Title TOSS 5 must use cron logging. Vuln_Discuss Cron logging can be used to trace the successful or unsuccessful execution of cron jobs. It can also be used to spot intrusions into the use of the cron facility by unauthorized and malicious users. Check_Content Verify "rsyslog" is configured to log cron events using the following command: Note: If another logging package is used, substitute the utility configuration file for "/etc/rsyslog.conf" or "/etc/rsyslog.d/*.conf" files. $ sudo grep -s cron /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.info;mail.none;authpriv.none;cron.none /var/log/messages /etc/rsyslog.conf:cron.* /var/log/cron If the command does not return a response, check for cron logging all facilities using the following command: $ sudo grep -s /var/log/messages /etc/rsyslog.conf /etc/rsyslog.d/*.conf /etc/rsyslog.conf:*.info;mail.none;authpriv.none;cron.none /var/log/messages If "rsyslog" is not logging messages for the cron facility or all facilities, this is a finding. Fix_Text Configure "rsyslog" to log all cron messages by adding or updating the following line to "/etc/rsyslog.conf" or a configuration file in the /etc/rsyslog.d/ directory: cron.* /var/log/cron Restart the rsyslog daemon for the changes to take effect. $ sudo systemctl restart rsyslog.service Not_Reviewed Vuln_Num V-282749 Rule_ID SV-282749r1201227_rule Severity medium Rule_Title The TOSS 5 audit system must take appropriate action when an error writing to the audit storage volume occurs. Vuln_Discuss It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. Check_Content Verify TOSS 5 takes the appropriate action when an audit processing failure occurs using the following command: $ sudo grep disk_error_action /etc/audit/auditd.conf disk_error_action = HALT If the value of the "disk_error_action" option is not "SYSLOG", "SINGLE", or "HALT", or the line is commented out, ask the system administrator (SA) to indicate how the system takes appropriate action when an audit process failure occurs. If there is no evidence of appropriate action, this is a finding. Fix_Text Configure TOSS 5 to shut down by default upon audit failure (unless availability is an overriding concern). Add or update the following line (depending on the configuration, "disk_error_action" can be set to "SYSLOG" or "SINGLE") in "/etc/audit/auditd.conf" file: disk_error_action = HALT If availability has been determined to be more important, and this decision is documented with the information system security officer (ISSO), configure the operating system to notify the SA and ISSO in the event of an audit processing failure by setting the "disk_error_action" to "SYSLOG". Not_Reviewed Vuln_Num V-282750 Rule_ID SV-282750r1201230_rule Severity medium Rule_Title The TOSS 5 audit system must take appropriate action when the audit storage volume is full. Vuln_Discuss It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. Check_Content Verify TOSS 5 takes the appropriate action when the audit storage volume is full using the following command: $ sudo grep disk_full_action /etc/audit/auditd.conf disk_full_action = HALT If the value of the "disk_full_action" option is not "SYSLOG", "SINGLE", or "HALT", or the line is commented out, ask the system administrator (SA) to indicate how the system takes appropriate action when an audit storage volume is full. If there is no evidence of appropriate action, this is a finding. Fix_Text Configure TOSS 5 to shut down by default upon audit failure (unless availability is an overriding concern). Add or update the following line (depending on the configuration, "disk_full_action" can be set to "SYSLOG" or "SINGLE") in "/etc/audit/auditd.conf" file: disk_full_action = HALT If availability has been determined to be more important, and this decision is documented with the information system security officer (ISSO), configure the operating system to notify the SA and ISSO in the event of an audit processing failure by setting the "disk_full_action" to "SYSLOG". Not_Reviewed Vuln_Num V-282751 Rule_ID SV-282751r1201233_rule Severity medium Rule_Title The TOSS 5 audit system must take appropriate action when the audit files have reached maximum size. Vuln_Discuss It is critical that when the operating system is at risk of failing to process audit logs as required, it takes action to mitigate the failure. Audit processing failures include software/hardware errors; failures in the audit capturing mechanisms; and audit storage capacity being reached or exceeded. Responses to audit failure depend upon the nature of the failure mode. Check_Content Verify TOSS 5 takes the appropriate action when the audit files have reached maximum size using the following command: $ sudo grep max_log_file_action /etc/audit/auditd.conf max_log_file_action = ROTATE If the value of the "max_log_file_action" option is not "ROTATE", "SINGLE", or the line is commented out, ask the system administrator (SA)to indicate how the system takes appropriate action when an audit storage volume is full. If there is no evidence of appropriate action, this is a finding. Fix_Text Configure TOSS 5 to rotate the audit log when it reaches maximum size. Add or update the following line in "/etc/audit/auditd.conf" file: max_log_file_action = ROTATE Not_Reviewed Vuln_Num V-282752 Rule_ID SV-282752r1201236_rule Severity medium Rule_Title TOSS 5 must write audit records to disk. Vuln_Discuss Audit data should be synchronously written to disk to ensure log integrity. This setting ensures all audit event data is written to disk. Check_Content If the system is configured to immediately offload audit records to an external system, this requirement is not applicable. Verify the audit system is configured to write logs to the disk using the following command: $ sudo grep write_logs /etc/audit/auditd.conf write_logs = yes If "write_logs" does not have a value of "yes", the line is commented out, or the line is missing, this is a finding. Fix_Text Configure the audit system to write log files to the disk. Edit the "/etc/audit/auditd.conf" file and add or update the "write_logs" option to "yes": write_logs = yes Restart the audit daemon for changes to take effect. Not_Reviewed Vuln_Num V-282753 Rule_ID SV-282753r1201612_rule Severity medium Rule_Title TOSS 5 must define default permissions for the bash shell. Vuln_Discuss The "umask "controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although "umask" can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. Check_Content Verify the "umask" setting is configured correctly in the "/etc/bashrc" file using the following command: Note: If the value of the "umask" parameter is set to "000" "/etc/bashrc" file, the severity is raised to a CAT I. $ grep umask /etc/bashrc umask 077 umask 077 If the value for the "umask" parameter is not "077", or the "umask" parameter is missing or is commented out, this is a finding. Fix_Text Configure TOSS 5 to define default permissions for all authenticated users using the bash shell. Add or edit the lines for the "umask" parameter in the "/etc/bashrc" file to "077": umask 077 Not_Reviewed Vuln_Num V-282754 Rule_ID SV-282754r1201614_rule Severity medium Rule_Title TOSS 5 must define default permissions for the c shell. Vuln_Discuss The "umask" controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although "umask "can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. Check_Content Verify the "umask" setting is configured correctly in the "/etc/csh.cshrc" file using the following command: Note: If the value of the "umask" parameter is set to "000" "/etc/csh.cshrc" file, the severity is raised to a CAT I. $ grep umask /etc/csh.cshrc umask 077 umask 077 If the value for the "umask" parameter is not "077", or the "umask" parameter is missing or is commented out, this is a finding. Fix_Text Configure TOSS 5 to define default permissions for all authenticated users using the c shell. Add or edit the lines for the "umask" parameter in the "/etc/csh.cshrc" file to "077": umask 077 Not_Reviewed Vuln_Num V-282755 Rule_ID SV-282755r1201616_rule Severity medium Rule_Title TOSS 5 must define default permissions for all authenticated users in such a way that the user can only read and modify their own files. Vuln_Discuss Setting the most restrictive default permissions ensures that when new accounts are created, they do not have unnecessary access. Check_Content Note: If the value of the "UMASK" parameter is set to "000" in "/etc/login.defs" file, the severity is raised to a CAT I. Verify TOSS 5 defines default permissions for all authenticated users in such a way that the user can only read and modify their own files using the following command: # grep -i umask /etc/login.defs UMASK 077 If the value for the "UMASK" parameter is not "077", or the "UMASK" parameter is missing or is commented out, this is a finding. Fix_Text Configure TOSS 5 to define default permissions for all authenticated users in such a way that the user can only read and modify their own files. Add or edit the lines for the "UMASK" parameter in the "/etc/login.defs" file to "077": UMASK 077 Not_Reviewed Vuln_Num V-282756 Rule_ID SV-282756r1201618_rule Severity medium Rule_Title TOSS 5 must define default permissions for the system default profile. Vuln_Discuss The "umask" controls the default access mode assigned to newly created files. A umask of 077 limits new files to mode 600 or less permissive. Although "umask "can be represented as a four-digit number, the first digit representing special access modes is typically ignored or required to be "0". This requirement applies to the globally configured system defaults and the local interactive user defaults for each account on the system. Check_Content Note: If the value of the "umask" parameter is set to "000" "/etc/profile" file, the severity is raised to a CAT I. Verify the "umask" setting is configured correctly in the "/etc/profile" file using the following command: $ grep umask /etc/profile umask 077 If the value for the "umask" parameter is not "077", or the "umask" parameter is missing or is commented out, this is a finding. Fix_Text Configure TOSS 5 to define default permissions for all authenticated users in such a way that the user can only read and modify their own files. Add or edit the lines for the "umask" parameter in the "/etc/profile" file to "077": umask 077 Not_Reviewed Vuln_Num V-282757 Rule_ID SV-282757r1201251_rule Severity high Rule_Title TOSS 5 must not allow an unattended or automatic logon to the system. Vuln_Discuss Failure to restrict system access to authenticated users negatively impacts operating system security. Check_Content Verify TOSS does not allow an unattended or automatic logon to the system via a graphical user interface. Note: This requirement assumes the use of the TOSS default graphical user interface, Gnome Shell. If the system does not have any graphical user interface installed, this requirement is not applicable. Check for the value of the "AutomaticLoginEnable" in the "/etc/gdm/custom.conf" file using the following command: $ sudo grep -i automaticloginenable /etc/gdm/custom.conf AutomaticLoginEnable=false Automatic logon as an authorized user allows access to any user with physical access to the operating system. If the value of "AutomaticLoginEnable" is missing or is not set to "false", this is a finding. Fix_Text Configure TOSS to not allow an unattended or automatic logon to the system via a graphical user interface. Add or edit the line for the "AutomaticLoginEnable" parameter in the [daemon] section of the "/etc/gdm/custom.conf" file to "false": [daemon] AutomaticLoginEnable=false Not_Reviewed Vuln_Num V-282758 Rule_ID SV-282758r1201254_rule Severity medium Rule_Title TOSS 5 must not allow users to override SSH environment variables. Vuln_Discuss SSH environment options potentially allow users to bypass access restriction in some configurations. Check_Content Verify unattended or automatic logon via SSH is disabled using the following command: $ sudo /usr/sbin/sshd -dd 2>&1 | awk '/filename/ {print $4}' | tr -d '\r' | tr '\n' ' ' | xargs sudo grep -iH '^\s*permituserenvironment' PermitUserEnvironment no If "PermitUserEnvironment" is set to "yes", is missing completely, or is commented out, this is a finding. Fix_Text Configure the TOSS 5 SSH daemon to not allow unattended or automatic logon to the system. Add or edit the following line in the "/etc/ssh/sshd_config" file: PermitUserEnvironment no Restart the SSH daemon for the setting to take effect: $ sudo systemctl restart sshd.service Not_Reviewed Vuln_Num V-282759 Rule_ID SV-282759r1201257_rule Severity high Rule_Title TOSS 5 must not allow unattended or automatic logon via the graphical user interface. Vuln_Discuss Failure to restrict system access to authenticated users negatively impacts operating system security. Check_Content Verify TOSS 5 does not allow an unattended or automatic logon to the system via a graphical user interface. Note: This requirement assumes the use of the TOSS 5 default graphical user interface, the GNOME desktop environment. If the system does not have any graphical user interface installed, this requirement is not applicable. Check for the value of the "AutomaticLoginEnable" in the "/etc/gdm/custom.conf" file using the following command: $ grep -i automaticlogin /etc/gdm/custom.conf [daemon] AutomaticLoginEnable=false If the value of "AutomaticLoginEnable" is not set to "false", this is a finding. Fix_Text Configure the GNOME desktop display manager to disable automatic login. Set "AutomaticLoginEnable" to "false" in the [daemon] section in "/etc/gdm/custom.conf". For example: [daemon] AutomaticLoginEnable=false Not_Reviewed Vuln_Num V-282760 Rule_ID SV-282760r1201260_rule Severity medium Rule_Title All TOSS local interactive user home directories must have mode 0770 or less permissive. Vuln_Discuss Users' home directories/folders may contain information of a sensitive nature. Nonprivileged users should coordinate any information sharing with a system administrator (SA) through shared resources. Check_Content Verify TOSS 5 limits the ability of nonprivileged users to grant other users direct access to the contents of their home directories/folders. Ensure the user permissions on all user home directories is set to 770 permissions using the following command: $ find $(awk -F: '($3>=1000)&&($7 !~ /nologin/){print $6}' /etc/passwd) -maxdepth 0 -not -perm 770 -ls 2> /dev/null If there is any output, this is a finding. Fix_Text Change the mode of interactive user's home directories to "0770." using the following command: Note: The example will be for the user "smithj." $ sudo chmod 0770 /home/smithj Not_Reviewed Vuln_Num V-282764 Rule_ID SV-282764r1201597_rule Severity medium Rule_Title TOSS 5 must, for password-based authentication, verify when users create or update passwords the passwords are not found on the list of commonly-used, expected, or compromised passwords in IA-5 (1) (a). Vuln_Discuss Password-based authentication applies to passwords regardless of whether they are used in single-factor or multifactor authentication. Long passwords or passphrases are preferable over shorter passwords. Enforced composition rules provide marginal security benefits while decreasing usability. However, organizations may choose to establish certain rules for password generation (e.g., minimum character length for long passwords) under certain circumstances and can enforce this requirement in IA-5(1)(h). Account recovery can occur, for example, in situations when a password is forgotten. Cryptographically protected passwords include salted one-way cryptographic hashes of passwords. The list of commonly used, compromised, or expected passwords includes passwords obtained from previous breach corpuses, dictionary words, and repetitive or sequential characters. The list includes context-specific words, such as the name of the service, username, and derivatives thereof. Check_Content Verify TOSS 5 is configured not allow users create or update passwords with passwords that are found on the list of commonly-used, expected, or compromised passwords using the following command: $ sudo grep pam_pwquality /etc/pam.d/system-auth or $ sudo grep pam_pwquality /etc/pam.d/password-auth password requisite pam_pwquality.so local_users_only If the parameter "pam_pwquality" is not set and required in at least one of the pam stacks, this is a finding. Fix_Text Configure TOSS 5 to verify when users create or update passwords, the passwords are not found on a list of commonly-used, expected, or compromised passwords by adding the following to the /etc/pam.d/password-auth and /etc/pam.d/system-auth files: password requisite pam_pwquality.so local_users_only Not_Reviewed Vuln_Num V-282768 Rule_ID SV-282768r1201307_rule Severity medium Rule_Title TOSS 5 must accept only external credentials that are NIST compliant. Vuln_Discuss Acceptance of only NIST-compliant external authenticators applies to organizational systems that are accessible to the public (e.g., public-facing websites). External authenticators are issued by nonfederal government entities and are compliant with [SP 800-63B]. Approved external authenticators meet or exceed the minimum federal governmentwide technical, security, privacy, and organizational maturity requirements. Meeting or exceeding federal requirements allows federal government relying parties to trust external authenticators in connection with an authentication transaction at a specified authenticator assurance level. Check_Content Sites must document external authenticators being used and that they are NIST compliant. The following command will verify that Kerberos is functional and produce the list of signing hosts: $ sudo klist -ekt /etc/krb5.keytab If external authenticators are being use that are not documented and are not NIST compliant, this is a finding. Fix_Text Document all NIST-compliant external authenticators in use. Not_Reviewed Vuln_Num V-282770 Rule_ID SV-282770r1201607_rule Severity medium Rule_Title TOSS 5 must include only approved trust anchors in trust stores or certificate stores managed by the organization. Vuln_Discuss Public key infrastructure (PKI) certificates are certificates with visibility external to organizational systems and certificates related to the internal operations of systems, such as application-specific time services. In cryptographic systems with a hierarchical structure, a trust anchor is an authoritative source (i.e., a certificate authority) for which trust is assumed and not derived. A root certificate for a PKI system is an example of a trust anchor. A trust store or certificate store maintains a list of trusted root certificates. Check_Content Verify TOSS 5 only uses trusted certificates using the following command: $ sudo trust list --filter=blocklist type: certificate label: Explicitly Distrust DigiNotar Root CA trust: distrusted category: authority If the "label" field is not configured with "Explicitly Distrust DigiNotar Root CA", if any other labels are present, the line is commented out, or the line is missing, this is a finding. Fix_Text Configure TOSS 5 to include only approved trust anchors in trust stores or certificate stores by adding certificates using the following command: $ sudo cp /path/to/new-ca-cert.pem /etc/pki/ca-trust/source/anchors/ $ sudo /bin/update-ca-trust Not_Reviewed Vuln_Num V-282771 Rule_ID SV-282771r1201293_rule Severity medium Rule_Title TOSS 5 must provide protected storage for cryptographic keys with organization-defined safeguards and/or hardware protected key store. Vuln_Discuss A Trusted Platform Module (TPM) is an example of a hardware-protected data store that can be used to protect cryptographic keys. Check_Content Verify TOSS 5 is using the TPM 2.0 hardware with the following command (if TPM 2.0 hardware is available): $sudo tpm2_pcrread <multiple SHA keys> If the command returns a status of "ERROR", and TPM 2.0 hardware is available, this is a finding. Fix_Text Configure TOSS 5 to provide protected storage for cryptographic keys by enabling TPM hardware, if available. Not_Reviewed Vuln_Num V-282772 Rule_ID SV-282772r1201296_rule Severity medium Rule_Title TOSS 5 must securely compare internal information system clocks at least every 24 hours. Vuln_Discuss Inaccurate time stamps make it more difficult to correlate events and can lead to an inaccurate analysis. Determining the correct time a particular event occurred on a system is critical when conducting forensic analysis and investigating system events. Sources outside the configured acceptable allowance (drift) may be inaccurate. Synchronizing internal information system clocks provides uniformity of time stamps for information systems with multiple system clocks and systems connected over a network. Depending on the infrastructure being used the "pool" directive may not be supported. Authoritative time sources include the United States Naval Observatory (USNO) time servers, a time server designated for the appropriate DOD network (NIPRNet/SIPRNet), and/or the Global Positioning System (GPS). Check_Content Verify TOSS 5 is securely comparing internal information system clocks at least every 24 hours with an NTP server with the following commands: $ sudo grep maxpoll /etc/chrony.conf server 0.us.pool.ntp.mil iburst maxpoll 16 If the "maxpoll" option is set to a number greater than 16 or the line is commented out, this is a finding. Verify the "chrony.conf" file is configured to an authoritative DOD or other U.S. Government time source using the following command: $ sudo grep -i server /etc/chrony.conf server 0.us.pool.ntp.mil If the parameter "server" is not set or is not set to an authoritative DOD or other U.S. Government time source, this is a finding. Fix_Text Configure TOSS 5 to securely compare internal information system clocks at least every 24 hours with an appropriate NTP server by adding/modifying the following line in the "/etc/chrony.conf file": server [ntp.server.name] iburst maxpoll 16 Not_Reviewed