Hackers on a Plane

BeyondTrust Research Team, April 11th, 2013

If I were cast in a movie in which the plotline centered on a person on a plane maliciously controlling the entire 550MPH Pringles Can via smartphone, I’d demand the movie be called ‘Hackers on a Plane’, just so people knew what they were getting into when purchasing their matinee ticket. However, this seemingly far-fetched plotline is now a reality via the culmination of three years of flight management systems (FMS) InfoSec research.

This year at Hack in the Box Amsterdam, N.Runs’ Hugo Teso, who happens to be a commercial pilot as well as a security researcher, demonstrated the capability to completely control an aircraft’s trajectory via spoofed communications from the ground. By leveraging known weaknesses in ADS-B (Automated Dependent Surveillance-Broadcast) and ACARS (Aircraft Communications Addressing and Reporting System), Teso could leverage vulnerabilities within flight management systems, manufactured by Honeywell and Thales, among others, on an aircraft to make the aircraft change heading, angle, and speed. However, there is catch: no hacking took place on actual aircraft (which would be quite dangerous), but merely PC-based flight training and simulation software.

According to European Aviation Safety Administration (EASA), as well as a spokesperson from Honeywell, there are significant differences between PC-based FMS training software, and FMS deployed in aircraft. FMS used in aircraft apparently contain “overwriting protection and redundancies” that supposedly provide some mitigation against exploitation, but this does not mean that embedded systems are not vulnerable to similar flaws. More importantly, this latest research (and the latest round of hype from popular media outlets) does not address the most glaring flaws of all: the lack of authentication concerning communication from the ground to aircraft. If the embedded FMS systems were developed over the last 30 years, “… following strict guidance and best practices that include … particular robustness”, then why did no one tackle the fairly obvious issue concerning how we talk to planes currently?

“…a network is only as secure as its weakest link…”

As mentioned in our CTO Marc Maiffret’s recent op-ed piece in the New York Times, we “typically do not hear about how attackers were able to put a virus or other malware on a system in the first place” but in this situation, we know. Research has been released over the past few years detailing how insecure ADS-B and ACARS is, but no governing body has addressed it directly, beyond the slow deployment of Aeronautical Telecommunications Network, which is the secure replacement for ACARS. Do we really have to wait for some tragedy to occur before we realize that security was not a fundamental part of the design process?