The key fob sends out a code which the car interprets to unlock the doors. Typically these codes are randomized to prevent hackers from reusing a previous code, but Subaru's implementation is flawed.

"An attacker can 'clone' the key fob, unlock cars and, when increasing the rolling code with a sufficiently high value, effectively render the user's key fob unusable," Wimmenhove wrote.

Tom Wimmenhove, a Dutch electronics designer, has discovered a flaw in the key fob system used by several Subaru models, a vulnerability the vendor has not patched and could be abused to hijack cars.

A computer engineer found the Subaru key fob's rolling code – the internal system used to securely lock and unlock car doors – was "predictable".

[Fileark] has instructions for reprogramming keyless entry devices for your car. His demonstration video, which you can see after the break, shows how to make one key fob work for two different veh… ...