Typo3 Extension "Events 2" vulnerabilities

The permission check for the frontend management update flow verified a different event than the one the request went on to modify. A user with frontend event management access could therefore modify events belonging to other organizers.

The frontend management plugin attributed a newly created event to the submitting user's organizer record only when the request supplied no organizer of its own. The accompanying permission check confirmed only that the submitting user held any organizer role. A user with frontend event management access could therefore create an event that is attributed to another organizer.