Input validation vulnerability in Mailrelay 2.1.1

The Mailrelay plugin for WordPress is a tool used by site administrators to manage their email accounts. Unfortunately, a security vulnerability has been identified in versions up to, and including, 2.1.1. This vulnerability, known as Cross-Site Request Forgery, is caused by either missing or incorrect nonce validation on the render_admin_page function. This makes it possible for unauthenticated attackers to change the plugin’s settings without the knowledge or consent of the administrator via a forged request if they are able to trick the administrator into performing an action such as clicking on a link.