Title

The operator must document all file system objects that have non-standard access control list settings. (Cat II impact)

Discussion

Access Control Lists allow an object owner to expand permissions on an object to specific users and groups in addition to the standard permission model. Non-standard Access Control List settings can allow unauthorized users to modify critical files.

Check Content

The root role is required. Identify all file system objects that have non-standard access control lists enabled. # find / \( -fstype nfs -o -fstype cachefs -o -fstype autofs \ -o -fstype ctfs -o -fstype mntfs -o -fstype objfs \ -o -fstype proc \) -prune -o -acl -ls This command should return no output. If output is created, this is a finding. If the files are approved to have ACLs by organizational security policy, document the files and the reason that ACLs are required.

Fix Text

The root role is required. Remove ACLs that are not approved in the security policy. For ZFS file systems, remove all extended ACLs with the following command: # chmod A- [filename] For UFS file systems Determine the ACLs that are set on a file: # getfacl [filename] Remove any ACL configurations that are set: # setfacl -d [ACL] [filename]

Additional Identifiers

Rule ID: SV-216204r603268_rule

Vulnerability ID: V-216204

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.