Mahara before 1.0.15, 1.1.x before 1.1.9, and 1.2.x before 1.2.5 has improper configuration options for authentication plugins associated with logins that use the single sign-on (SSO) functionality, which allows remote attackers to bypass authentication via an empty password. NOTE: some of these details are obtained from third party information.
http://www.securityfocus.com/bid/41319
http://wiki.mahara.org/Release_Notes/1.2.5
http://wiki.mahara.org/Release_Notes/1.1.9