The login method in LoginModule implementations in Apache Geronimo 2.0 does not throw FailedLoginException for failed logins, which allows remote attackers to bypass authentication requirements, deploy arbitrary modules, and gain administrative access by sending a blank username and password with the command line deployer in the deployment module.
geronimo.apache.org/2007/08/13/apache-geronimo-v20-release-delayed-due-to-security-issue.html
geronimo.apache.org/2007/08/21/apache-geronimo-201-released.html
www.nabble.com/Geronimo-2.0-Release-suspended-due-to-security-issue-found-before-release-t4263667s134.html
issues.apache.org/jira/browse/GERONIMO-1201
issues.apache.org/jira/browse/GERONIMO-3404