TDuck survey form through 6.0 Authorization Bypass via User-Controlled Submission IDs in POST /user/form/data/delete/{formKey}

TDuck survey form through 6.0 contains an insecure direct object reference vulnerability that allows authenticated users to delete other users' form submissions by supplying arbitrary submission ids. Attackers can place their own formKey in the path and iterate sequential submission ids in the request body to permanently delete submissions platform-wide.