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

NixOS must generate audit records when successful/unsuccessful attempts to delete privileges occur.

DISA Rule

SV-268164r1131133_rule

Vulnerability Number

V-268164

Group Title

SRG-OS-000466-GPOS-00210

Rule Version

ANIX-00-001730

Severity

CAT II

CCI(s)

• CCI-000172 - Generate audit records for the event types defined in AU-2 c that include the audit record content defined in AU-3.

Weight

10

Fix Recommendation

Configure NixOS to record attempts to delete privileges.

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

security.audit.rules = [
"-a always,exit -F path=/run/current-system/sw/bin/usermod -F perm=x -F auid>=1000 -F auid!=unset -k privileged-usermod"
];

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

Check Contents

Verify NixOS generates audit records when attempts to delete privileges occur with the following command:

$ sudo auditctl -l | grep usermod

-a always,exit -S all -F path=/run/current-system/sw/bin/usermod -F perm=x -F auid>=1000 -F auid!=-1 -k privileged-usermod

If the command does not return an audit rule for "usermod", this is a finding.

Vulnerability Number

V-268164

Documentable

False

Rule Version

ANIX-00-001730

Severity Override Guidance

Verify NixOS generates audit records when attempts to delete privileges occur with the following command:

$ sudo auditctl -l | grep usermod

-a always,exit -S all -F path=/run/current-system/sw/bin/usermod -F perm=x -F auid>=1000 -F auid!=-1 -k privileged-usermod

If the command does not return an audit rule for "usermod", this is a finding.

Check Content Reference

M

Target Key

5658