bbPress Members Only <= 1.2.1 - Cross-Site Request Forgery

The bbPress Members Only plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 1.2.1. This is due to missing or incorrect nonce validation on the 'Optional Settings' page. This makes it possible for unauthenticated attackers to gain access to otherwise restricted admin actions via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.