Nearly 100 million Volkswagen vehicles are affected by a vulnerability that would allow an attacker to remotely and discretely unlock a car without a key.

The bug affects the keyless entry system of nearly every car Volkswagen has sold since 1995 and was discovered by University of Birmingham computer scientist Flavio Garcia along with a team of researchers, according to Wired.

Later this week at the Usenix Security Symposium in Austin, a team of Birmingham University researchers will unveil this attack and a separate attack which affects millions of additional vehicles including Alfa Romeo, Citroen, Fiat, Ford, Mitsubishi, Nissan, Opel, and Peugeot.

Both attacks can be performed with very little cost using a software defined radio connected to a laptop or even an Arduino board with an attached radio receiver.

Combined with a different attack which Garcia disclosed last year, an attacker could effectively unlock a car, start its ignition and drive off.