SQLLoginModule in Apache Geronimo 2.0 through 2.1 does not throw an exception for a nonexistent username, which allows remote attackers to bypass authentication via a login attempt with any username not contained in the database.
https://issues.apache.org/jira/browse/GERONIMO-3543
http://www.vupen.com/english/advisories/2007/3676
http://www.vupen.com/english/advisories/2007/3675
http://www.securityfocus.com/bid/26287
http://www-1.ibm.com/support/docview.wss?uid=swg21286105
http://secunia.com/advisories/27482