The Popup Builder – Create highly converting, mobile friendly marketing popups. plugin for WordPress is vulnerable to unauthorized access of functionality due to a missing capability check on several functions in all versions up to, and including, 4.3.1. While some functions contain a nonce check, the nonce can be obtained from the profile page of a logged-in user. This allows subscribers to perform several actions including deleting subscribers and perform blind Server-Side Request Forgery.
The product does not perform an authorization check when an actor attempts to access a resource or perform an action.