The WP Freeio plugin for WordPress is vulnerable to Privilege Escalation in all versions up to, and including, 1.2.21. This is due to the process_register() function not restricting what user roles a user can register with. This makes it possible for unauthenticated attackers to supply the administrator role during registration and gain administrator access to the site.
The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor.