Title

The Sendmail service must not have the wizard backdoor active. (Cat III impact)

Discussion

Very old installations of the Sendmail mailing system contained a feature whereby a remote user connecting to the SMTP port can enter the WIZ command and be given an interactive shell with root privileges.

Check Content

Check the /etc/mail/sendmail.cf configuration file for "wiz" configuration. # cat /etc/mail/sendmail.cf |tr '\011' ' ' | tr -s ' ' | sed -e 's/^[ \t]*//' | grep -v "^#" |\ grep -i wiz If an entry is found for wiz, this is a finding.

Fix Text

If the WIZ command is enabled on Sendmail, it should be disabled by adding this line to the sendmail.cf configuration file (note that it must be typed in uppercase): OW* For the change to take effect, kill the Sendmail process, refreeze the sendmail.cf file, and restart the Sendmail process.

Additional Identifiers

Rule ID: SV-35093r1_rule

Vulnerability ID: V-4694

Group Title: GEN004700

Expert Comments

CCIs tied to check.

Controls tied to check. These are derived from the CCIs shown above.