The Rolling PWN


Modern vehicles are often equipped with a remote keyless entry system. These RKE systems allow unlocking or starting the vehicle remotely. The goal of our research was to evaluate the resistance of a modern-day RKE system. Our research disclosed a Rolling-PWN attack vulnerability affecting all Honda vehicles currently existing on the market (From the Year 2012 up to the Year 2022). This weakness allows anyone to permanently open the car door or even start the car engine from a long distance.

The Rolling-PWN bug is a serious vulnerability. We found it in a vulnerable version of the rolling codes mechanism, which is implemented in huge amounts of Honda vehicles. A rolling code system in keyless entry systems is to prevent replay attack. After each keyfob button pressed the rolling codes synchronizing counter is increased. However, the vehicle receiver will accept a sliding window of codes, to avoid accidental key pressed by design. By sending the commands in a consecutive sequence to the Honda vehicles, it will be resynchronizing the counter. Once counter resynced, commands from the previous cycle of the counter worked again. Therefore, those commands can be used later to unlock the car at will.