A large proportion of around 100 million Volkswagen Audi Group vehicles manufactured since 1995 can be remotely unlocked by hackers, research by the University of Birmingham and German security firm Kasper & Oswald has revealed.
VW vehicles produced between 1995 and 2016 are affected, including those from VAG companies such as Audi, Seat and Skoda.
The report suggests that a homemade radio costing as little as £30 would be all that a criminal would need to spy on key fob signals and potentially gain access to target cars.
Volkswagen have stated that not all of their vehicles are affected, with the current-generation Golf, Tiguan, Touran and Passat amongst those which cannot be broken into in this way.
Researchers cloned digital keys which allowed them to reverse-engineer the keyless entry system in affected models, providing them with some master cryptographic keys. This allowed a variety of VW Group vehicles to be unlocked.
The research team contacted Volkswagen before making their findings public, and agreed not to release certain key pieces of information.
A spokesman for Volkswagen made it clear that starting the car's engine via this type of attack was not possible.
Security experts have stated that it would take an academic-level knowledge of cryptography to be able to exploit the vulnerability, reassuring owners of affected vehicles.