Buffer overflow in SmartMax MailMax POP3 daemon (popmax) 4.8 allows remote attackers to execute arbitrary code via a long USER command.
http://www.securityfocus.com/bid/5285
http://www.iss.net/security_center/static/9651.php
http://archives.neohapsis.com/archives/bugtraq/2002-07/0245.html