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V-270734

CAT III (Low)

Ubuntu 24.04 LTS must be configured such that Pluggable Authentication Module (PAM) prohibits the use of cached authentications after one day.

Rule ID

SV-270734r1155240_rule

STIG

Canonical Ubuntu 24.04 LTS Security Technical Implementation Guide

Version

V1R5

CCIs

CCI-002007

Discussion

If cached authentication information is out-of-date, the validity of the authentication information may be questionable.

Check Content

Note: If smart card authentication is not being used on the system, this requirement is not applicable. 

Verify PAM prohibits the use of cached authentications after one day with the following command:
 
$ sudo grep offline_credentials_expiration /etc/sssd/sssd.conf /etc/sssd/conf.d/*.conf 
offline_credentials_expiration = 1 
 
If "offline_credentials_expiration" in "/etc/sssd/sssd.conf" or in a file with a name ending in .conf in the "/etc/sssd/conf.d/" directory, is not set to "1", is commented out, is missing, or conflicting results are returned, this is a finding.

Fix Text

Configure PAM 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 
 
Note: It is valid for this configuration to be in a file with a name that ends with ".conf" and does not begin with a "." in the "/etc/sssd/conf.d/" directory instead of the "/etc/sssd/sssd.conf" file.