Attacks made against older versions of sendmail. When supplied with a correct password, WIZ commands can convert the SMTP connection into a remote shell.
A bug in the WIZ command has been known to exist for several years; even if no password is supplied, the password check could always succeed. If successfully allowed into the system, the user would see the message, “Please pass, oh mighty wizard,” but if not allowed into the system, the user would see the message, “You wascal wabbit! Wandering wizards won’t win!”
This bug became part of the 1988 Morris Worm adventure and it is little wonder that the WIZ command feature has not been part of sendmail since around 1990.
Graham, R. Hacking Lexicon. [Online, 2001.] Robert Graham Website. http://www.linuxsecurity.com/resource_files/documentation/hacking-dict.html.