NixOS must enforce a delay of at least four seconds between logon prompts following a failed logon attempt.
Severity | Group ID | Group Title | Version | Rule ID | Date | STIG Version |
|---|---|---|---|---|---|---|
| medium | V-268171 | SRG-OS-000480-GPOS-00226 | ANIX-00-001870 | SV-268171r1134782_rule | 2025-08-19 | 1 |
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.
ℹ️ Check
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
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