DISA STIGS Viewer

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   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If cached authentication information is out-of-date, the validity of the authentication information may be questionable.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-72102r1039420_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