The Feedzy plugin for WordPress is vulnerable to a type of attack called Cross-Site Request Forgery (CSRF). This vulnerability exists in versions up to 3.4.2, and it happens because the plugin has missing or incorrect security checks in a function called save_feedzy_post_type_meta(). This means that an unauthenticated attacker could potentially update the post meta data of a WordPress site if they can trick an administrator into clicking on a link.