Over on YouTube Talking Sasquach has recently tested custom firmware for the Flipper Zero that can entirely break the rolling code security system used on most modern vehicles. Rolling code security works by using a synchronized algorithm between a transmitter and receiver to generate a new, unique code for each transmission, preventing replay attacks and unauthorized access.

In the past we've discussed an attack against rolling code security systems called RollJam, which works by jamming the original keyfob signal so the vehicle cannot receive it, and at the same time recording it for later use. However, this attack is difficult to perform in reality.

For this new attack to work, all that is needed is a single button-press capture from the keyfob, without any jamming. Just from that single capture, it is able to emulate all the keyfob's functions, including lock, unlock, and unlock trunk. A consequence of this is that the original keyfob gets out of sync, and will no longer function.

According to the Talking Sasquatch, the attack works by simply reverse engineering the rolling code sequence, either through sequence leaks or prior brute forcing of the sequence from a large list of known codes. However, another article mentions that the firmware is based on the "RollBack" attack, which works by playing back captured rolling codes in a specific order to initiate a 'rollback' of the synchronization system.

Regardless of the method, videos demonstrating the attack show that only a single capture is needed to emulate a keyfob completely.

Affected vehicles include Chrysler, Dodge, Fiat, Ford, Hyundai, Jeep, Kia, Mitsubishi and Subaru. As of yet, there appears to be no easy fix for this, other than mass vehicle recalls.