Modern cars could be vulnerable to wireless hacking, research by the University of California San Diego and the University of Washington has revealed.
The researchers showed that by taking over a car's computers, they could disable the brakes, stop the engine and control the door locks.
The experiments accessed the computer systems mainly from inside the car, but researchers said attacks could get easier as carmakers add more wireless connectivity.
Fewer computer diagnostic ports in cars need direct access to operate and hack as these systems are being wirelessly enabled, said Barmak Meftah, chief products officer at security firm Fortify Software.
"It is a relatively small step to modify the code and allow hackers an easy and wireless back door into a car's computer system," he said.
The researchers were able to load new firmware onto their own circuitboard and, by plugging the board into the car's internal network, translate the data flowing between the vehicle and a laptop.
This reverse engineering process allowed the researchers to develop a customised vehicle network interface and effectively take control of the car's electronic nervous system.
"The killer hack was when the researchers were able to generate network commands wirelessly from one car to another," said Meftah.
"In theory this will eventually allow a wireless drive-by attack on the firmware of a car," he said.
Attacks could potentially disable a vehicle's central locking and ignition protection systems to enable thieves to make an easy getaway.