747s as flying Unix hosts: SCADA in the sky

From Craig S Wright, vice president of Global Institute for Cybersecurity + Research, a look at the use of SCADA systems that are connected to the Internet. You probably remember SCADA from the starring role it played in the Stuxnet worm.

For those who do not know, 747's are big flying Unix hosts. At the time, the engine management system on this particular airline was Solaris based. The patching was well behind and they used telnet as SSH broke the menus and the budget did not extend to fixing this. The engineers could actually access the engine management system of a 747 in route. If issues are noted, they can re-tune the engine in air.

The issue here is that all that separated the engine control systems and the open network was NAT based filters. There were (and as far as I know this is true today), no extrusion controls. They filter incoming traffic, but all outgoing traffic is allowed. For those who engage in Pen Testing and know what a shoveled shell is... I need not say more.

(Thanks, Ashkan!)

(Image: 747, a Creative Commons Attribution (2.0) image from dannyboymalinga's photostream)


  1. UNIX (Berkeley System V) was my introduction to computing and Internet-working. Once I got over the sheer terror of the learning curve our our “new electronic office wonder and the future of the paper-less office,” all this turned into a lot of fun and I haven’t looked  back, since. I was telnetting (with NAT filtering) to remote systems until just after the turn of the century when the rest of the world was becoming addicted to AOL and Yahoo! The switch to Secure SHells became really important with the advent of broadband – and continuous – connections.

  2. So how useful is this when Stephen Harper brings in his Lawful Access Legislation and starts spying on the Canadian internet traffic? I live by an airport and have 747s flying over top of me at 15 minute intervals. Can I use them to post blogs critical of the Alberta Tar Sands without having to fear being spied on, charged with terrorism and put away in one of Harper’s shiny new for-profit prisons?

  3. Well… I’m sure there is absolutely _nothing_ that can go wrong there!

    The article is a good read! (Although now I need to go google a few terms…)

  4. “For those who engage in Pen Testing and know what a shoveled shell is… I need not say more.”

    Well a lot of us don’t do those things.  So if you’re going to pretend to disseminate the news how about actually doing that?  Your reference is worthless to anyone who doesn’t do those things.

    1. I agree that it would be nice for an explanation, but a simple google search on the term would have easily solved the mystery.

      1. If I want to spend time looking things like that up I’ll read Physical Review Letters. Why write it down at all if you’re going to make esoteric references? Isn’t the point of news to disseminate information in a meaningful and accessible way? Is it your claim the author did that?

  5. The issue here is that all that separated the engine control systems and the open network was NAT based filters.

    Does not necessarily mean the engine control systems were accessible from the Internet. Only that they were accessible from whatever network could access the plane.

    I imagine the FADEC (look it up) systems were on a 10.x.x.x private address space along with the rest of the avionics, and things like telnet were port-forwarded to the WAN IP of the radio/satellite uplink. Exactly like every other network in existence.

    This doesn’t mean that the uplink wasn’t either a

    a) point-to-point private circuit or direct radio link.
    b) secure VPN over a public carrier.

    This isn’t a factory where someone can walk over to the controllers. When your SCADA network is 30,000 feet in the air, having no outside access has its ups and downs ;-)

    What is scary, if you RTFA, is that said plane network has the avionics and the in-flight entertainment on the same Ethernet, but with different VLANs. I would worry more about misbehaving devices (or people.. excuse me, what network is that in-flight Wi-Fi riding on??) on the plane than I would outside threats.

    Oh, FYI, a shoveled (or reverse) shell is like a telnet or SSH session, but the server connects OUT to the client, vs the client connecting IN to the server. You don’t need a forwarded port to shovel a shell.

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