The Custom 404 Pro plugin for WordPress is vulnerable to Cross-Site Request Forgery in versions up to, and including, 3.7.1. This is due to missing or incorrect nonce validation on the custom_404_pro_admin_init function. This makes it possible for unauthenticated attackers to delete logs, via forged request granted they can trick a site administrator into performing an action such as clicking on a link.
CVE Vulnerability