Notification Bar <= 2.2 - Cross-Site Request Forgery

The Notification Bar plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.2. This is due to missing or incorrect nonce validation on the 'subscriber-list-empty.php' file. This makes it possible for unauthenticated attackers to empty the subscriber list via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.