The system must not use .forward files.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-4385	GEN004580	SV-45868r1_rule		Medium

Description
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.

STIG	Date
SUSE Linux Enterprise Server v11 for System z Security Technical Implementation Guide	2018-09-19

Details

Check Text ( C-43176r1_chk )
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.

Check Text ( C-43176r1_chk )

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.

Fix Text (F-39246r1_fix)
Disable forwarding for sendmail and remove .forward files from the system Procedure: Edit the /etc/mail/sendmail.mc file to change the ForwardPath entry to a null path by adding the line define(`confFORWARD_PATH`,`') rebuild the sendmail.cf file. Remove all .forward files on the system # find / -name .forward -delete