NixOS must enforce a delay of at least four seconds between logon prompts following a failed logon attempt.
Overview
| Finding ID | Version | Rule ID | IA Controls | Severity |
| V-268171 | ANIX-00-001870 | SV-268171r1134782_rule | CCI-000366 | medium |
| Description | ||||
| Limiting the number of logon attempts over a certain time interval reduces the chances that an unauthorized user may gain access to an account. | ||||
| STIG | Date | |||
| Anduril NixOS Security Technical Implementation Guide | 2025-08-19 | |||
Details
Check Text (C-268171r1134782_chk)
Verify NixOS enforces a four-second delay between logon attempts with the following command:
$ grep -I delay /etc/login.defs
FAIL_DELAY 4
If "FAIL_DELAY" is not set to "4" or greater, is commented out, or is missing, this is a finding.
Fix Text (F-71998r1131148_fix)
Configure NixOS to enforce a four-second delay between logon attempts.
Add the following Nix code to the NixOS Configuration, usually located in /etc/nixos/configuration.nix or /etc/nixos/flake.nix:
security.loginDefs.settings."FAIL_DELAY" = "4";
Rebuild and switch to the new NixOS configuration:
$ sudo nixos-rebuild switch