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V-833

CAT I (High)

Files executed through a mail aliases file must be owned by root and must reside within a directory owned and writable only by root.

Rule ID

SV-45851r1_rule

STIG

SUSE Linux Enterprise Server v11 for System z Security Technical Implementation Guide

Version

V1R12

CCIs

CCI-000225

Discussion

If a file executed through a mail aliases file is not owned and writable only by root, it may be subject to unauthorized modification. Unauthorized modification of files executed through aliases may allow unauthorized users to attain root privileges.

Check Content

Verify the ownership of files referenced within the sendmail aliases file.

Procedure:
# more /etc/aliases
Examine the aliases file for any utilized directories or paths.

# ls -lL <directory or file path>
Check the owner for any paths referenced. 
Check if the file or parent directory is owned by root. If not, this is a finding.

Fix Text

Edit the /etc/aliases file (alternatively, /usr/lib/sendmail.cf). Locate the entries executing a program. They will appear similar to the following line:

Aliasname: : /usr/local/bin/ls (or some other program name)

Ensure root owns the programs and the directory(ies) they reside in by using the chown command to change owner to root.
Procedure:
# chown root <file or directory name>