The ForumWP – Forum & Discussion Board Plugin plugin for WordPress is vulnerable to Privilege Escalation via Insecure Direct Object Reference in all versions up to, and including, 2.0.2 via the submit_form_handler due to missing validation on the 'user_id' user controlled key. This makes it possible for authenticated attackers, with subscriber-level access and above, to change the email address of administrative user accounts which can then be leveraged to reset the administrative users password and gain access to their account.
The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.