Input validation vulnerability in Fontiran 2.1

The Fontiran plugin for WordPress, up to version 2.1, is vulnerable to a type of security vulnerability called Cross-Site Request Forgery. This vulnerability is caused by either missing or incorrect validation of something called a “nonce” on a function called fi_add_rule. This vulnerability allows unauthenticated attackers to change plugin settings if they can get a site administrator to click on a malicious link.