Title

NixOS must generate audit records when successful/unsuccessful attempts to delete security objects occur. (Cat II impact)

Discussion

Without generating audit records that are specific to the security and mission needs of the organization, it would be difficult to establish, correlate, and investigate the events relating to an incident or identify those responsible for one. Audit records can be generated from various components within the information system (e.g., module or policy filter).

Check Content

Verify that NixOS generates audit records when successful/unsuccessful attempts to delete security objects occur with the following command: $ sudo auditctl -l | grep /bin/ch -a always,exit -S all -F path=/run/current-system/sw/bin/chage -F perm=x -F auid>=1000 -F auid!=-1 -k privileged-chage -a always,exit -S all -F path=/run/current-system/sw/bin/chcon -F perm=x -F auid>=1000 -F auid!=-1 -k perm_mod If the command does not return an audit rule for "chage" and "chcon", this is a finding.

Fix Text

Configure /etc/nixos/configuration.nix to audit attempts to delete security objects by adding the following configuration settings: security.audit.rules = [ "-a always,exit -F path=/run/current-system/sw/bin/chage -F perm=x -F auid>=1000 -F auid!=unset -k privileged-chage" "-a always,exit -F path=/run/current-system/sw/bin/chcon -F perm=x -F auid>=1000 -F auid!=unset -k perm_mod" ]; Rebuild the system with the following command: $ sudo nixos-rebuild switch

Additional Identifiers

Rule ID: SV-268165r1039383_rule

Vulnerability ID: V-268165

Group Title: SRG-OS-000468-GPOS-00212

Expert Comments

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