The EventON WordPress plugin before 2.1.2 does not validate that the event_id parameter in its eventon_ics_download ajax action is a valid Event, allowing unauthenticated visitors to access any Post (including unpublished or protected posts) content via the ics export functionality by providing the numeric id of the post.
https://wpscan.com/vulnerability/72d80887-0270-4987-9739-95b1a178c1fd