wpForo Forum < 2.4.16 Privilege Escalation via Role Synchronization Handler

wpForo Forum 2.4.14 contains a missing capability check vulnerability that allows authenticated users to trigger bulk wpForo usergroup reassignment via the wpforo_synch_roles AJAX handler. Attackers access the usergroups admin page, accessible to any authenticated user, to obtain a nonce, then remap all wpForo usergroups to arbitrary WordPress roles.