The Paid Memberships Pro – Content Restriction, User Registration, & Paid Subscriptions plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.12.10. This is due to missing or incorrect nonce validation on multiple functions. This makes it possible for unauthenticated attackers to subscribe to, modify, or cancel membership for a user via a forged request granted they can trick a user into performing an action such as clicking on a link.