The aliases file must be group-owned by root, sys, bin, or system.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-22438	GEN004370	SV-45848r2_rule		Medium

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

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

Details

Check Text ( C-43146r2_chk )
If the “sendmail” or “postfix” packages are not installed, this is not applicable. Check the group ownership of the alias files. Procedure: for sendmail: # ls -lL /etc/aliases If the file is not group-owned by root, this is a finding. # ls -lL /etc/aliases.db If the file is not group-owned by root, this is a finding. for postfix: Verify the location of the alias file. # postconf alias_maps This will return the location of the "aliases" file, by default "/etc/aliases". # ls -lL If the file is not group-owned by root, this is a finding. # ls -lL If the file is not group-owned by root, this is a finding.

Check Text ( C-43146r2_chk )

If the “sendmail” or “postfix” packages are not installed, this is not applicable.

Check the group ownership of the alias files.

Procedure:
for sendmail:
# ls -lL /etc/aliases
If the file is not group-owned by root, this is a finding.

# ls -lL /etc/aliases.db
If the file is not group-owned by root, this is a finding.

for postfix:
Verify the location of the alias file.
# postconf alias_maps

This will return the location of the "aliases" file, by default "/etc/aliases".

# ls -lL
If the file is not group-owned by root, this is a finding.

# ls -lL
If the file is not group-owned by root, this is a finding.

Fix Text (F-39232r2_fix)
Change the group-owner of the /etc/aliases file. Procedure: for sendmail: # chgrp root /etc/aliases # chgrp root /etc/aliases.db for postfix # chgrp root # chgrp root