A security researcher has devised a small hardware that can hijack a variety of popular drones mid-flight, allowing attackers to lock the owner out and give them complete control over the device. The device runs over the most popular wireless transmission control protocol called DSMx. The loophole relies on the fact that DSMx protocol does not encrypt the’secret’ key that pairs a controller and hobbyist device. So, it is possible for an attacker to steal this secret key by launching several brute-force attacks.
Source: https://thehackernews.com/2016/10/how-to-hack-drone.html