STIGQter: STIG Summary: Anduril NixOS Security Technical Implementation Guide Version: 1 Release: 2 Benchmark Date: 01 Oct 2025:

NixOS must not allow direct login to the root account.

DISA Rule

SV-268138r1131081_rule

Vulnerability Number

V-268138

Group Title

SRG-OS-000109-GPOS-00056

Rule Version

ANIX-00-000900

Severity

CAT II

CCI(s)

• CCI-004045 - Require users to be individually authenticated before granting access to the shared accounts or resources.

Weight

10

Fix Recommendation

Configure NixOS to ensure the root user is locked.

Add the following Nix code to the NixOS Configuration, usually located in /etc/nixos/configuration.nix or /etc/nixos/flake.nix:

users.mutableUsers = false;

Rebuild and switch to the new NixOS configuration:
$ sudo nixos-rebuild switch

Check Contents

Verify the NixOS operating system prevents directly logging in to the root account with the following command:

$ sudo passwd -S root

root L 01/02/1970 -1 -1 -1 -1

If the second field in the output is not "L" or "NP", then the root account is not locked and has a password configured, and this is a finding.

Vulnerability Number

V-268138

Documentable

False

Rule Version

ANIX-00-000900

Severity Override Guidance

Verify the NixOS operating system prevents directly logging in to the root account with the following command:

$ sudo passwd -S root

root L 01/02/1970 -1 -1 -1 -1

If the second field in the output is not "L" or "NP", then the root account is not locked and has a password configured, and this is a finding.

Check Content Reference

M

Target Key

5658