Cybersecurity Vulnerabilities in Commercial Aviation

The US Government Accounting Office has published a report into the US Federal Aviation Administration’s possible vulnerabilities to cyberattack. One of my respected colleagues, John Knight, was interviewed for it. (While I’m at it, let me recommend highly John’s inexpensive textbook Fundamentals of Dependable Computing for Software Engineers. It has been very well thought through and there is a lot of material which students will not find elsewhere.)

None of what’s in the report surprises me. There are three main points (in the executive summary).

First, the GAO suggests the FAA devise a threat model for its ground-based ATC/ATM systems. (And, I presume, that the FAA respond to the threat model it devises.) I am one of those people who consider it self-evident that threat models need to be formulated for all sorts of critical infrastructure. One of the first questions I ask concerning security is “what’s the threat model?“. If the answer is “there isn’t one” then can anybody be suprised that this is first on the list?

Lots of FAA ground-based systems aren’t geared to deal with cybersecurity threats – many of them are twenty or more years old and cybersecurity wasn’t an issue in the same way it is coming to be. Many systems communicate over their own dedicated networks, so that would involve a more or less standard physical-access threat model. But many of them don’t. Many critical inter-center communications are carried over public telephone lines and are therefore vulnerable to attacks through the public networks, say on the switches. Remember when an AT&T 4ESS switch went down in New York almost a quarter century ago? I can’t remember if it was that outage or another one during which the ATCOs called each other on their private mobiles to keep things working. A human attacker trying to do a DoS on communications would probably try to take out mobile communications also. (So there’s the first threat for the budding threat model – a DoS on communications)

If the FAA don’t want to do a model themselves, couldn’t they just get one from a European ally and adapt it? The infrastructures aren’t that dissimilar on the high level and anything would be a help initially.

Second, when the FAA decided they were OK with the manufacturer putting avionics and passenger in-flight entertainment (IFE) data on the same databuses on the Boeing 787, many of us thought this premature and unwise and said so privately to colleagues (one of them even found the correspondence). We have recently had people claim to be able to access critical systems through the IFE (see below). I have reported on one previous credible claim on vulnerabilities in avionics equipment.

The GAO is suggesting that such configurations be thought through a little more thoroughly. The basic point remains: isn’t it abundantly clear that the very best way to ensure as much non-interference as possible is physical separation? Who on earth was thinking a decade ago that non-interference wouldn’t be that much of an issue? Certainly not me.

Third, the other matters the GAO addressed are organisational, which is important of course for the organisation but of little technical interest.

Concerning accessing critical avionics systems through the IFE, Fox News reports that Cyber security researcher Chris Roberts was pulled off a US commercial flight and interrogated by the FBI for a number of hours.

A colleague commented that “they are going after the messenger.” But let’s look at this a little more carefully.

Chris Roberts is CTO and founder of One World Labs in Denver. Staff at One World consist of a CEO who is a lawyer, a CFO and a VP of sales and marketing, and two technical employees, one of whom is Roberts, who is the company founder. The board appears to be well-balanced, with a former telecommunications-industry executive and a military SIGINT expert amongst others.

One World claims to have the “world’s largest index of dark content“, something called OWL Vision, to which they apparently sell access. One wonders how they manage to compile and sustain such a resource with only two technical people in the company, but, you know, kudos to them if it’s true.

According to the first line of his CV, Roberts is “Regarded as one of the world’s foremost experts on counter threat intelligence within the cyber security industry“. His CV consists of engagements as speaker, and press interviews – there is nothing which one might regard as traditional CV content (his One World colleagues provide more traditional info: degrees, previous work experience and so on). His notable CV achievements for 2015 are a couple of interviews with Fox.

Apparently he told Fox News in March, quoted in the article above, “We can still take planes out of the sky thanks to the flaws in the in-flight entertainment systems. Quite simply put, we can theorize on how to turn the engines off at 35,000 feet and not have any of those damn flashing lights go off in the cockpit…… If you don’t have people like me researching and blowing the whistle on system vulnerabilities, we will find out the hard way what those vulnerabilities are when an attack happens.

Read that first sentence again. He can take planes out of the sky due to flaws in the IFE, he says. Does it surprise anybody that the FBI or Homeland Security would want to find out exactly what he means? Maybe before he gets on a flight, taking some computer equipment with him? It is surely the task of security services to ensure he is not a threat in any way. If you were a passenger on that airplane, wouldn’t you like at least to know that he is not suicidal/paranoid/psychotic? In fact, wouldn’t you rather he got on the plane with a nice book to read and sent his kit ahead, separately, by courier?

It has been no secret for fourteen years that if you are going to make public claims about your capabilities you can expect security agencies nowadays to take them at face value. Would we want it otherwise?

Let us also not ignore the business dynamics. You have read here about a small Denver company, its products and claimed capabilities. I am probably not the only commentator. All at the cost to a company employee of four hours’ interrogation and the temporary loss of one laptop. And without actually having to publish their work and have people like me analyse it.