Title

The aliases file must be group-owned by root, sys, smmsp, or bin. (Cat II impact)

Discussion

If the alias file is not group-owned by root or a system group, an unauthorized user may modify the file to add aliases to run malicious code or redirect email.

Check Content

Note: If sendmail is not installed, this requirement is not applicable. Find the alias files on the system. Procedure: # egrep '^O(A| AliasFile)' /etc/mail/sendmail.cf If the "alias file" is an NIS or LDAP map, this check is not applicable. The default location is /etc/mail/aliases. Check the group ownership of the alias file and the hashed version of it used by sendmail. Procedure: # ls -lL /etc/mail/aliases /etc/mail/aliases.db If the files are not group-owned by root, sys, smmsp, or bin, this is a finding.

Fix Text

Change the group owner of the /etc/mail/aliases files. Procedure: # chgrp bin /etc/mail/aliases # chgrp smmsp /etc/mail/aliases.db

Additional Identifiers

Rule ID: SV-220045r858545_rule

Vulnerability ID: V-220045

Group Title: SRG-OS-000480

Expert Comments

CCIs tied to check.

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