The sendmail service must not have the wizard backdoor active.

Overview

Finding ID	Version	Rule ID	IA Controls	Severity
V-4694	GEN004700	SV-37513r1_rule	ECSC-1	Low

Description
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.

STIG	Date
Red Hat Enterprise Linux 5 Security Technical Implementation Guide	2016-06-01

Details

Check Text ( C-36172r3_chk )
Log into the sendmail server with telnet and test the "wiz" command. Procedure: # telnet localhost 25 Trying 127.0.0.1... Connected to locahost.localdomain (127.0.0.1). Escape character ... Once the telnet greeting is complete type: wiz If you do not get a "Command unrecognized: " message, this is a finding.

Fix Text (F-31423r2_fix)
If the WIZ command exists on sendmail then the version of sendmail is archaic and should be replaced with the latest version from RedHat. WIZ is not available on any sendmail distribution of RHEL. However, 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.

Fix Text (F-31423r2_fix)

If the WIZ command exists on sendmail then the version of sendmail is archaic and should be replaced with the latest version from RedHat.
WIZ is not available on any sendmail distribution of RHEL. However, 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.