It can if the only ECU on both buses has read only access (e.g. uses a receive only transceiver or if the TX pin of that transceiver is grounded). Also signed u

It can if the only ECU on both buses has read only access (e.g. uses a receive only transceiver or if the TX pin of that transceiver is grounded). Also signed updates aren’t rocket science and work well enough if you keep the verification code minimal, well reviewed and formally verified if possible.