login.php for PHPAuction allows remote attackers to gain privileges via a direct call to login.php with the action parameter set to "insert," which adds the provided username to the adminUsers table.
http://www.phpauction.org/viewnew.php?id=5
http://www.iss.net/security_center/static/9462.php
http://archives.neohapsis.com/archives/bugtraq/2002-07/0014.html