The alias file must be owned by root.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-831	GEN004360	SV-45827r1_rule		Medium

Description
If the alias file is not owned by root, 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-43144r1_chk )
Check the ownership of the alias files. Procedure: for sendmail: # ls -lL /etc/aliases # ls -lL /etc/aliases.db If all the files are not 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. # ls -lL # ls -lL If all the files are not owned by root, this is a finding.

Fix Text (F-39214r1_fix)
Change the owner of the /etc/aliases file to root. Procedure: for sendmail: # chown root /etc/aliases # chown root /etc/aliases.db for postfix # chown root # chown root