The AutoCatSet plugin for WordPress is vulnerable to Cross-Site Request Forgery in all versions up to, and including, 2.1.4. This is due to missing or incorrect nonce validation on the autocatset_ajax function. This makes it possible for unauthenticated attackers to trigger automatic recategorization of posts via a forged request granted they can trick a site administrator into performing an action such as clicking on a link.
https://plugins.trac.wordpress.org/browser/autocatset/trunk/lib/ajax.php#L5
https://plugins.trac.wordpress.org/browser/autocatset/trunk/autocatset.php#L93