Event Tickets < 5.30.3.1 - Unauthenticated Attendee Name Disclosure via Single Attendee REST Endpoint

The Event Tickets and Registration WordPress plugin before 5.30.3.1 does not correctly check whether an event displays a public attendee list before returning one of its attendees over the REST API, allowing unauthenticated users to retrieve the names of attendees of events that do not show a public attendee list.