This vulnerability allows adjacent attackers to inject arbitrary Controller Area Network messages on vulnerable installations of Volkswagen Customer-Link App 1.30 and HTC Customer-Link Bridge. Authentication is not required to exploit this vulnerability. The specific flaw exists within the Customer-Link App and Customer-Link Bridge. The issue results from the lack of a proper protection mechanism against unauthorized firmware updates. An attacker can leverage this vulnerability to inject CAN messages. Was ZDI-CAN-5264.