Title

All files and directories must have a valid owner. (Cat II impact)

Discussion

Unowned files and directories may be unintentionally inherited if a user is assigned the same UID as the UID of the unowned files.

Check Content

Check the system for files with no assigned owner. Procedure: # find / -nouser -print If any files have no assigned owner, this is a finding.

Fix Text

All directories and files (executable and data) will have an identifiable owner and group name. Either trace files to an authorized user, change the file's owner to root, or delete them. Determine the legitimate owner of the files and use the chown command to set the owner and group to the correct value. If the legitimate owner cannot be determined, change the owner to root (but make sure none of the changed files remain executable because they could be Trojan horses or other malicious code). Examine the files to determine their origin and the reason for their lack of an owner/group.

Additional Identifiers

Rule ID: SV-785r2_rule

Vulnerability ID: V-785

Group Title: GEN001160

Expert Comments

CCIs tied to check.

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