Ubuntu 24.04 LTS must be configured such that Pluggable Authentication Module (PAM) prohibits the use of cached authentications after one day.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-270734 | UBTU-24-400340 | SV-270734r1066691_rule | CCI-002007 | low |
| Description | ||||
| If cached authentication information is out-of-date, the validity of the authentication information may be questionable. | ||||
| STIG | Date | |||
| Canonical Ubuntu 24.04 LTS Security Technical Implementation Guide | 2025-05-16 | |||
Details
Check Text (C-270734r1066691_chk)
Note: If smart card authentication is not being used on the system, this is not applicable.
Verify that 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" is not set to a value of "1" in "/etc/sssd/sssd.conf" or in a file with a name ending in .conf in the "/etc/sssd/conf.d/" directory, this is a finding.
Fix Text (F-74668r1066690_fix)
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.