Unlike us common folk who still use metal keys to start our Ford Model T's to drive to the nickelodeon, Teslas use futuristic fobs that transmit radio signals to their cars to hands-free unlock the doors and the motor. But researchers at KU Leuven in Belgium discovered that the encryption of the key fob of Tesla's most popular car, the Model S, was much weaker than the car's, making it ridiculously simple to hack. With some pretty basic radio equipment, they managed to pick up the signals from the fob, hack its cryptographic key in under two seconds, clone the information, and trick the car into unlocking itself. And they can get it all done by just calmly walking past the car and the owner with an eensy-weensy hacking tool.
The weakness was discovered all the way back in 2017, but it took until the June update of 2018 for Tesla to fix its security to counter the hack. And while the KUL researcher held off on publishing the findings until after the patch, that did mean that for over a year, stealing a Model S was like taking candy from Elon Musk after doing Joe Rogan's podcast. Tesla has advised that if drivers really want to be safe, they should activate the feature that requires them to input a PIN to unlock their car, and also deactivate their keyless system and just press the manual button to open and close the doors. Of course, most Tesla owners don't use or want these features, because they specifically spent all that money on a sci-fi car in order to not have to unlock and start it like a Volvo station wagon with a combination lock on the wheel.