UserPlus <= 2.0 - Authenticated (Editor+) Registration Form Update to Privilege Escalation

The UserPlus plugin for WordPress is vulnerable to unauthorized modification of data due to an improper capability check on the 'save_metabox_form' function in versions up to, and including, 2.0. This makes it possible for authenticated attackers, with editor-level permissions or above, to update the registration form role to administrator, which leads to privilege escalation.