All these little devices talk to each other on an open network. They listen in to every message that’s sent, and they don’t verify where a specific command is coming from. Miller says all of this makes cars easy to attack.
Any sensor attached to the processor on the network is vulnerable. So after [Charlie] Miller and [Chris] Valasek learned the code that controlled the ECUs on the two cars they were testing, they were able to cause all kind of havoc.
They were able to jerk the wheel at high speeds in the Prius. They could cause the car to accelerate or brake. They could beep the horn or set off the crash preparation system and jerk the seatbelts back.
In the Ford Escape, if the driver was moving slowly, they could turn the wheel or even kill the brake. In fact, once Miller forgot that the hack was running on his Ford Escape and he drove it into his garage.