NixOS must not allow an unattended or automatic logon to the system via the console.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-268172 | ANIX-00-001880 | SV-268172r1131152_rule | CCI-000366 | high |
| Description | ||||
| Failure to restrict system access via the console to authenticated users negatively impacts operating system security. | ||||
| STIG | Date | |||
| Anduril NixOS Security Technical Implementation Guide | 2025-08-19 | |||
Details
Check Text (C-268172r1131152_chk)
Verify NixOS does not allow an unattended or automatic logon to the system via the console with the following command:
$ grep -iR autologon.user /etc/nixos
If "services.xserver.displayManager.autologon.user" is defined and is not "null", this is a finding.
Fix Text (F-71999r1131151_fix)
Configure NixOS to not allow an unattended or automatic logon to the system via the console.
Add the following Nix code to the NixOS Configuration, usually located in /etc/nixos/configuration.nix or /etc/nixos/flake.nix:
services.xserver.displayManager.autologon.user = null;
Rebuild and switch to the new NixOS configuration:
$ sudo nixos-rebuild switch
A reboot is required for the changes to take effect.