Input validation vulnerability in Reservation.Studio widget 1.0.9

The Reservation.Studio widget plugin for WordPress versions up to and including 1.0.9 is vulnerable to a security attack called Cross-Site Request Forgery. This means that an unauthenticated attacker can update plugin settings without being logged in. They can do this by tricking a site administrator into clicking on a link or performing some other action. This is possible because the admin.php file does not have enough security measures or validation in place.