RHEL 9 must prohibit the use of cached authenticators after one day.

STIG ID: RHEL-09-631020  |  SRG: SRG-OS-000383-GPOS-00166 |  Severity: medium |  CCI: CCI-002007 |  Vulnerability Id: V-258133

Vulnerability Discussion

If cached authentication information is out-of-date, the validity of the authentication information may be questionable.

Check

Verify that 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 with 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 with 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

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