V-223589

Discussion

Without confidentiality protection mechanisms, unauthorized individuals may gain access to sensitive information via a remote access session. 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. Encryption provides a means to secure the remote connection to prevent unauthorized access to the data traversing the remote access connection (e.g., RDP), thereby providing a degree of confidentiality. The encryption strength of a mechanism is selected based on the security categorization of the information. Satisfies: SRG-OS-000033-GPOS-00014, SRG-OS-000120-GPOS-00061

Check Content

Locate the SSH daemon configuration file, which may be found in "/etc/ssh/" directory.

Alternately:

From Unix System Services ISPF Shell, navigate to ribbon select tools.

Select option 1 - Work with Processes.

If SSH Daemon is not active, this is not a finding.

Examine SSH daemon configuration file. 
sshd_config

If there are no ciphers lines, or the ciphers list contains any cipher not starting with "aes", this is a finding.

If the MACs line is not configured to "hmac-sha1" or greater, this is a finding.

Examine the z/OS-specific sshd server systemwide configuration. 
zos_sshd_config

If any of the following is untrue, this is a finding.

FIPSMODE=YES
CiphersSource=ICSF
MACsSource=ICSF