A 19 year old hacker and security research says he was able to control features of dozens of Tesla vehicles because of a security vulnerability in a third-party software, according to a report by Vice.

While critical functions like steering, braking, and acceleration could not be accessed — the teen says he could still unlock doors, take drivers on trips, and blast music.

Tesla did not respond when asked for comment by Vice. And the hacker claims he’s been working with the third-party app to fix their flaws.