Configure auditing of unsuccessful ownership changes
An XCCDF Rule
Description
Ensure that unsuccessful attempts to change an ownership of files or directories are audited. The following rules configure audit as described above:
## Unsuccessful ownership change -a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change -a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change -a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change -a always,exit -F arch=b64 -S lchown,fchown,chown,fchownat -F exit=-EPERM -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-changeLoad new Audit rules into kernel by running:
augenrules --loadNote: This rule uses a special set of Audit rules to comply with OSPP 4.2.1. You may reuse this rule in different profiles. If you decide to do so, it is recommended that you inspect contents of the file closely and make sure that they are alligned with your needs.
Rationale
Unsuccessful attempts to change an ownership of files or directories might be signs of a malicious activity. Having such events audited helps in monitoring and investigation of such activities.
- ID
- xccdf_org.ssgproject.content_rule_audit_owner_change_failed
- Severity
- Medium
- References
- Updated
Remediation - Shell Script
# Remediation is applicable only in certain platforms
if [ ! -f /.dockerenv ] && [ ! -f /run/.containerenv ]; then
cat << 'EOF' > /etc/audit/rules.d/30-ospp-v42-6-owner-change-failed.rules
## Unsuccessful ownership change
-a always,exit -F arch=b32 -S lchown,fchown,chown,fchownat -F exit=-EACCES -F auid>=1000 -F auid!=unset -F key=unsuccessful-owner-change
Remediation - Ansible
- name: Put contents into /etc/audit/rules.d/30-ospp-v42-6-owner-change-failed.rules
according to policy
copy:
dest: /etc/audit/rules.d/30-ospp-v42-6-owner-change-failed.rules
content: |
## Unsuccessful ownership change