The Online Booking & Scheduling Calendar for WordPress by vcita plugin for WordPress is vulnerable to Cross-Site Request Forgery due to a missing nonce check on the vcita_logout_callback function in versions up to, and including, 4.2.10. This makes it possible for unauthenticated to logout a vctia connected account which would cause a denial of service on the appointment scheduler, via a forged request granted they can trick a site user into performing an action such as clicking on a link.
The web application does not, or cannot, sufficiently verify whether a request was intentionally provided by the user who sent the request, which could have originated from an unauthorized actor.