The Booking Package WordPress plugin before 1.5.29 requires a token for exporting the ical representation of it's booking calendar, but this token is returned in the json response to unauthenticated users performing a booking, leading to a sensitive data disclosure vulnerability.
https://wpscan.com/vulnerability/3cd1d8d2-d2a4-45a9-9b5f-c2a56f08be85