I’ve written before about CANbus, and electronics in cars. My own car, despite being only a mid-size, mid-range hatch a few years old, has a good few electronic modules, and CANbus to connect them. Cars have 3 flavours of CAN- one for the drivetrain and chassis- so this episode would use that, as would this one, and one for the interior stuff (for both instrumentation, and stuff like the radio shifting it’s volume up and down with speed, or automatic closing of windows when locking), and then one more for connecting diagnostic gear like VCDS or Torque.
These individual networks are gatewayed together as they run at different speeds, and there’s no real control over what can talk over these networks, which isn’t really a problem, you’d think: the car is a closed system, so unless you connect diagnostic equipment or get very interested and attach a Raspberry Pi to the CANbus (great article there), it hardly matters. There have been scare stories in the press of clever people hacking cars before, but these have involved a direct, cable connection to the diagnostic port, so no big deal, and the networks *have* to be gatewayed for the instruments to display your speed, and for the diagnostic kit to work.
It is now becoming commonplace to include connected entertainment systems into cars. These will have an internet connection, either via a tethered mobile phone, or with a SIM card fitted. There’s various names for this, according to manufacturer.
The scary bit here is that potentially, you’re now exposing the CAN to the Internet. Depending on how well secured things are (or aren’t), you might possibly allow anyone on the Internet to, say, disable the brakes or transmission, as detailed here by The Register. As we get more and more fancy devices (like, say, auto-parking) then the exposure of safety-critical things like steering and braking, which used to be simple, mechanical, systems to attack becomes greater.
It’s certainly the case that some cars (VAG ones, for sure, in my experience) only allow full access to some critical modules with a login- but these logins are quite well publicised, which means you’d better be pretty sure about your car’s fancy entertainment system being secure, and staying secure when it is 15 years old and the manufacturer no longer supports it. Maybe the further research of these guys, with intrusion detection for CAN has merit?