Popup Box <= 3.2.4 is vulnerable to Cross Site Request Forgery (CSRF) vulnerability

The Popup Box plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.2.4. This is due to missing or incorrect nonce validation on a function. This makes it possible for unauthenticated attackers to perform an unauthorized action via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.