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

Successful/unsuccessful uses of the rename, unlink, rmdir, renameat, and unlinkat system calls in NixOS must generate an audit record.

DISA Rule

SV-268095r1130992_rule

Vulnerability Number

V-268095

Group Title

SRG-OS-000042-GPOS-00020

Rule Version

ANIX-00-000280

Severity

CAT II

CCI(s)

• CCI-000135 - Generate audit records containing the organization-defined additional information that is to be included in the audit records.

Weight

10

Fix Recommendation

Configure NixOS to generate audit records for any successful/unsuccessful attempts to use the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls.

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 arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete"
"-a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=unset -k delete"
];

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

Check Contents

Verify NixOS generates an audit record upon successful/unsuccessful attempts to use the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls with the following command:

$ sudo auditctl -l | grep -w 'rename\|unlink\|rmdir'

-a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=-1 -k delete
-a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=-1 -k delete

If the command does not return an audit rule for "rename", "unlink", "rmdir", "renameat", and "unlinkat", this is a finding.

Note: The "-k" allows for specifying an arbitrary identifier. The string following "-k" does not need to match the example output above.

Vulnerability Number

V-268095

Documentable

False

Rule Version

ANIX-00-000280

Severity Override Guidance

Verify NixOS generates an audit record upon successful/unsuccessful attempts to use the "rename", "unlink", "rmdir", "renameat", and "unlinkat" system calls with the following command:

$ sudo auditctl -l | grep -w 'rename\|unlink\|rmdir'

-a always,exit -F arch=b32 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=-1 -k delete
-a always,exit -F arch=b64 -S rename,unlink,rmdir,renameat,unlinkat -F auid>=1000 -F auid!=-1 -k delete

If the command does not return an audit rule for "rename", "unlink", "rmdir", "renameat", and "unlinkat", this is a finding.

Note: The "-k" allows for specifying an arbitrary identifier. The string following "-k" does not need to match the example output above.

Check Content Reference

M

Target Key

5658