Biagiotti Membership <= 1.0.2 - Authentication Bypass via biagiotti_membership_check_facebook_user

The Biagiotti Membership plugin for WordPress is vulnerable to authentication bypass in all versions up to, and including, 1.0.2. This is due to the plugin not properly verifying a user's identity prior to authenticating them. This makes it possible for unauthenticated attackers to log in as other users, such as administrators, granted they have access to an email.