RegistrationMagic <= 6.0.7.1 - Unauthenticated Privilege Escalation via admin_order

The RegistrationMagic plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 6.0.7.1. This is due to the 'add_menu' function is accessible via the 'rm_user_exists' AJAX action and allows arbitrary updates to the 'admin_order' setting. This makes it possible for unauthenticated attackers to injecting an empty slug into the order parameter, and manipulate the plugin's menu generation logic, and when the admin menu is subsequently built, the plugin adds 'manage_options' capability for the target role. Note: The vulnerability can only be exploited unauthenticated, but further privilege escalation requires at least a subscriber user.