Title

The alias file must have mode 0644 or less permissive. (Cat II impact)

Discussion

Excessive permissions on the aliases file may permit unauthorized modification. If the alias file is modified by an unauthorized user, they may modify the file 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 permissions 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 alias files have a mode more permissive than 0644, this is a finding.

Fix Text

Change the mode of the /etc/mail/aliases files (or equivalent, such as /usr/lib/aliases) to 0644. Procedure: # chmod 0644 /etc/mail/aliases /etc/mail/aliases.db

Additional Identifiers

Rule ID: SV-226931r858549_rule

Vulnerability ID: V-226931

Group Title: SRG-OS-000312

Expert Comments

CCIs tied to check.

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