CVE-2005-3101
The password reset feature in Movable Type before 3.2 generates different error messages depending on whether a user exists or not, which allows remote attackers to determine valid usernames.
Date published : 2005-09-28
http://www.securityfocus.com/bid/14911
http://archives.neohapsis.com/archives/fulldisclosure/2005-11/0091.html