The Paid Membership Subscriptions WordPress plugin before 3.0.8 does not verify that the subscription being modified through its change-subscription checkout belongs to the current user, allowing any authenticated user with Subscriber-level access and above to take over another members subscription and overwrite its plan, status and expiration.
The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor.
Access control involves the use of several protection mechanisms such as:
When any mechanism is not applied or otherwise fails, attackers can compromise the security of the product by gaining privileges, reading sensitive information, executing commands, evading detection, etc. There are two distinct behaviors that can introduce access control weaknesses: