Input validation vulnerability in Force First and Last Name as Display Name 1.2

The Force First and Last Name as Display Name plugin for WordPress has a security flaw in versions up to 1.2. This means that unauthenticated attackers can change user information without needing a password. They can do this by getting a site administrator to click on a link. The flaw is due to the plugin not having the proper security measures in place to protect against this kind of attack.