NixOS must prohibit the use of cached authenticators after one day.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-268178 | ANIX-00-002050 | SV-268178r1039543_rule | CCI-002007 | medium |
| Description | ||||
| If cached authentication information is out-of-date, the validity of the authentication information may be questionable. | ||||
| STIG | Date | |||
| Anduril NixOS Security Technical Implementation Guide | 2024-10-25 | |||
Details
Check Text (C-268178r1039543_chk)
Verify NixOS, for PKI-based authentication, only caches authenticators for one day with the following command:
$ sudo grep expiration /etc/sssd/sssd.conf
offline_credentials_expiration = 1
If the offline_credentials_expiration is not set to "1" or is commented out, this is a finding.
Fix Text (F-72005r1039542_fix)
Configure /etc/nixos/configuration.nix to prohibit the use of cached credentials older than one day by adding the following configuration settings. Note that the entire sssd.conf must be entered in this option:
services.sssd.config = ''
...
[pam]
offline_credentials_expiration = 1
...
'';
Rebuild the system with the following command:
$ sudo nixos-rebuild switch