Insecure direct object reference (IDOR) vulnerability in the MatchPoint API, which relies on the `actingasuser` HTTP header without verifying the requester's authorization for the specified user. Manipulation of sequential identifiers allows access to personal, banking, and financial data, private messages, and QR codes for physical access, as well as the ability to modify third-party accounts, change passwords, impersonate users, and transfer virtual balances.
Authorization Bypass Through User-Controlled Key The system's authorization functionality does not prevent one user from gaining access to another user's data or record by modifying the key value identifying the data.