Eventin <= 4.1.22 - Authenticated (Contirbutor+) Local File Inclusion via 'event_layout' Parameter

The Eventin – Event Calendar, Event Registration, Tickets & Booking (AI Powered) plugin for WordPress is vulnerable to Local File Inclusion in all versions up to, and including, 4.1.22 via the 'event_layout' parameter parameter. This makes it possible for authenticated attackers, with contributor-level access and above, to include and execute arbitrary .php files on the server, allowing the execution of any PHP code in those files. This can be used to bypass access controls, obtain sensitive data, or achieve code execution in cases where .php file types can be uploaded and included. The etn_manage_event capability is assigned to Contributors by default, meaning any Contributor-level user can set the malicious event_layout value via the REST API without any additional configuration.