NixOS must enable the audit daemon.

Severity	Group ID	Group Title	Version	Rule ID	Date	STIG Version
medium	V-268080	SRG-OS-000004-GPOS-00004	ANIX-00-000030	SV-268080r1039128_rule	2024-10-25	1

Description
Once an attacker establishes access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to create an account. Auditing account creation actions provides logging that can be used for forensic purposes. Note: For the "security.audit.enable" configuration, both "true" and "lock" are valid values. The "true" value allows for loading of audit rules (synonymous with "-e 1" in audit rules), while the "lock" value loads audit rules and enforces that the rules cannot be changed without the system rebooting (synonymous with "-e 2"). Setting this value to "lock" is recommended to be performed as the final step in configuring the audit daemon. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000254-GPOS-00095, SRG-OS-000344-GPOS-00135, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000122-GPOS-00063, SRG-OS-000358-GPOS-00145

Description

Once an attacker establishes access to a system, the attacker often attempts to create a persistent method of reestablishing access. One way to accomplish this is for the attacker to create an account. Auditing account creation actions provides logging that can be used for forensic purposes. Note: For the "security.audit.enable" configuration, both "true" and "lock" are valid values. The "true" value allows for loading of audit rules (synonymous with "-e 1" in audit rules), while the "lock" value loads audit rules and enforces that the rules cannot be changed without the system rebooting (synonymous with "-e 2"). Setting this value to "lock" is recommended to be performed as the final step in configuring the audit daemon. Satisfies: SRG-OS-000004-GPOS-00004, SRG-OS-000254-GPOS-00095, SRG-OS-000344-GPOS-00135, SRG-OS-000348-GPOS-00136, SRG-OS-000349-GPOS-00137, SRG-OS-000350-GPOS-00138, SRG-OS-000351-GPOS-00139, SRG-OS-000352-GPOS-00140, SRG-OS-000353-GPOS-00141, SRG-OS-000354-GPOS-00142, SRG-OS-000122-GPOS-00063, SRG-OS-000358-GPOS-00145

ℹ️ Check
Verify NixOS has the audit service configured with the following command: $ grep security.audit /etc/nixos/configuration.nix security.auditd.enable = true; security.audit.enable = true; If auditd, and audit are not set to true or lock, this is a finding.

✔️ Fix
Configure the system to enable the audit service by adding or updating the following configurations in /etc/nixos/configuration.nix: security.auditd.enable = true; security.audit.enable = true; Rebuild the system with the following command: $ sudo nixos-rebuild switch