V-4385

Discussion

The .forward file allows users to automatically forward mail to another system. Use of .forward files could allow the unauthorized forwarding of mail and could potentially create mail loops which could degrade system performance.

Check Content

Determine if sendmail is installed 
# rpm -qa | grep -i sendmail

This check only applies to systems that have the sendmail package installed.  
Check forwarding capability from sendmail.

Procedure:
grep "0 ForwardPath" /etc/mail/sendmail.cf

If the entry contains a file path, this is a finding.

Search for any .forward in users home directories on the system by:

# for pwline in `cut -d: -f1,6 /etc/passwd`; do homedir=`echo ${pwline}|cut -d: -f2`;username=`echo ${pwline} | cut -d: -f1`;echo $username `stat -c %n $homedir/.forward 2>/dev/null`; done|egrep "\.forward"

If any users have a .forward file in their home directory, this is a finding.