Two security researchers at a Black Hat security conference demonstrated how they were able to break into a Subaru Outback using a technique they call "war texting" in just a few hours, a revelation sure to warrant a mention in the REI customer newsletter.
The technique appears to apply to cars using a cell-based system for unlocking and remote start (like GM and Mercedes also use). The hackers established their own local GSM network and intercepted signals sent between the server/car to sniff out the passwords.
It's probably a minor threat to cars as the work required seems too great considering you'll still probably need a key to get the car to drive. The bigger threat exists if the "war texting" procedure is used to hack into other similarly controlled systems like traffic signals. Also, because it sounds like something tweens would be really good at.
Update: A tipster points out that the slides from their presentation (PDF) make it sound like the hack was done using an aftermarket system, which makes more sense given Subaru's lack of telematics.
Photo Credit: Shutterstock.com