The WPForms plugin for WordPress is vulnerable to unauthorized modification of data due to a missing capability check on the 'wpforms_is_admin_page' function in versions starting from 1.8.4 up to, and including, 1.9.2.1. This makes it possible for authenticated attackers, with Subscriber-level access and above, to refund payments and cancel subscriptions.
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.