Five graduate students and their professor have discovered three different ways to send rogue commands from a computer laptop to interfere with an airborne hobby drone's normal operation and land it or send it plummeting.
The Johns Hopkins University, Baltimore, USA, computer security team has raised concerns about the ease with which hackers could cause these increasingly popular robotic devices to ignore their human controllers and land or, more drastically, crash.
Drones, or unmanned aerial vehicles (UAVs), have become very popular in a short space of time. A recent article in US magazine Fortune stated that drone sales have tripled in the last 12 months, to the period ending April 2016. A recent Federal Aviation Administration (FAA) report predicted that 2.5 million hobby-type and commercial drones would be sold in 2016.
Hobby drones are typically flown for recreation and aerial photography or videography. More advanced commercial drones can handle more demanding tasks. Farmers have begun using drones with specialised cameras to survey their fields and help determine when and where water and fertiliser should be applied. Advanced commercial drones can also help in search and rescue missions located in challenging terrain and deliver crucial medicines to remote areas. Retailers such as Amazon are exploring the use of drones to deliver merchandise to customers.
However, the Johns Hopkins research team has found that in the haste to satisfy consumer demands, drone makers may have left a few digital doors unlocked.
“You see it with a lot of new technology,” said. Lanier A. Watkins, who supervised the drone research. "Security is often an afterthought. The value of our work is in showing that the technology in these drones is highly vulnerable to hackers."
Watkins is a senior cyber security research scientist in the university's Whiting School of Engineering, Department of Computer Science. Over the last few months, Watkins' students applied what they'd learned on their course about information security, conducting experiments in wireless network penetration testing on a popular hobby drone. In doing this, the team was able to develop "exploits" from the vulnerabilities found to disrupt the process that enables a drone's operator on the ground to manage its flight.
An "exploit," explained Michael Hooper, one of the student researchers, "is a piece of software typically directed at a computer program or device to take advantage of a programming error or flaw in that device."
In the team's first successful exploit, the students bombarded a drone with about 1,000 wireless connection requests in rapid succession, each asking for control of the airborne device. This digital deluge overloaded the aircraft's central processing unit, causing it to shut down. That sent the drone into what the team referred to as "an uncontrolled landing."
In the second successful hack, the team sent the drone an exceptionally large data packet, exceeding the capacity of a buffer in the aircraft's flight application. Again, this caused the drone to crash.
For the third exploit, the researchers repeatedly sent a fake digital packet from their laptop to the drone's controller, telling it that the packet's sender was the drone itself. Eventually, the researchers said, the drone's controller started to "believe" that the packet sender was indeed the aircraft itself. It severed its own contact with the drone, which eventually led to the drone making an emergency landing.
"We found three points that were actually vulnerable, and they were vulnerable in a way that we could actually build exploits for," Watkins said. "We demonstrated here that not only could someone remotely force the drone to land, but they could also remotely crash it in their yard and just take it."
In accordance with university policy, the researchers described their drone exploit findings in a Vulnerability Disclosure Package and sent it early this year to the maker of the drone that was tested. By the end of May, the company had not responded to the findings. More recently, the researchers have begun testing higher-priced drone models to see if these devices are similarly vulnerable to hacking.
Watkins said he hopes the studies serve as a wake-up call so that future drones for recreation, aerial photography, package deliveries and other commercial and public safety tasks will leave the factories with enhanced security features already on board, instead of relying on later "bug fix" updates, when it may be too late.