REDCap 8.11.6-9.x - Unauthenticated Information Disclosure via Messenger CSV Export
An issue was discovered in REDCap 8.11.6 through 9.x before 10. The messenger's CSV feature (that allows users to export their conversation threads as CSV) allows non-privileged users to export one another's conversation threads by changing the thread_id parameter in the request to the endpoint Messenger/messenger_download_csv.php?title=Hey&thread_id={THREAD_ID}.