The Service Finder Bookings plugin for WordPress is vulnerable to privilege escalation via account takeover in all versions up to, and including, 5.0. This is due to the plugin not properly validating a user's identity prior to (1) performing a post-booking auto-login or (2) updating their profile details (e.g. password). This makes it possible for unauthenticated attackers to (1) login as an arbitrary user if their email address is known or (2) change an arbitrary user's password, including administrators, and leverage that to gain access to their account.
The product requires authentication, but the product has an alternate path or channel that does not require authentication.