Ubuntu 24.04 LTS must be configured such that Pluggable Authentication Module (PAM) prohibits the use of cached authentications after one day.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| low | V-270734 | SRG-OS-000383-GPOS-00166 | UBTU-24-400340 | SV-270734r1155240_rule | 2026-02-06 | 1 |
Description
If cached authentication information is out-of-date, the validity of the authentication information may be questionable.
ℹ️ Check
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
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.