Hacker News Reader

Comment by davrosthedalek | Hacker News Reader

I had a projector firmware freeze up hard on me during a port scan. There is some risk there.

I used to work at a university, and would routinely (with authorisation) nmap the entire /16. I discovered this would freeze the TCP/IP stack on a bunch of VMS boxes on campus - luckily on VMS that was restartable without bouncing the box :-)

So what does that say about the wisdom of port scanning a machine your life is currently depending on?

He probably should've done his port scan once the plane was on the ground. Though I'd be REALLY worried if there was even the slightest risk of network access to the IFE causing a flight control device of any kind to seize up, and would hope that someone at Boeing made sure that was not possible.

If that plane ever plans to enter US or EU airspace, there is a literal air-gap between the IFE and the flight systems.

Then how is it showing the flight metrics?

I wouldn’t guess they would add double sensors for all that information.

Or did you mean well protected, instead of literal air gap?

One way connection of some kind? Its not an air gap but may functionally work the same way.

Optoisolators are a prolific and an extremely cheap electrical component that performs the "air-gap" functionality.

No, that's not airgapping.

Electrical safety airgapping and information security airgapping are different, and entirely unrelated. If data can pass from one side to the other it's not airgapped (from an infosec perspective).

Fiber needs transmitter and receiver transducers. If each side has only one of those, data can literally flow only in one direction. So it's still infosec-airgapped in the other.

No, data diodes are a different (but related) concept. An airgap implies no information transfer, either in or out. Use an airgap when information leakage must be stopped (as well as remote attacks), use a data diode when information can be released but you need to stop remote attacks.

Fiber optic connections aren't required, anything with separate transmit and receive lines can be turned into a data diode (as long as the protocols used permit it). RS232 null modem cables with the RX lines disconnected are a classic.

I don't know enough about airplanes to know if it would be unencrypted but they radio all of that same data to the ground in some way, could the IFE system just passively listen to that broadcast?

GPS + external sensors for pressure, wheels, …

I am not a Boeing engineer, but I do have some experience in avionics design.

The flight critical systems would be isolated from in-flight entertainment system (IFE). The IFE probably has a listen-only tap to flight metric info on an ARINC databus from the flight computer. I did a quick search and looks like 787 uses ARINC 667, a fiber optic interconnect.

The Federal Aviation Administration has issued special conditions for the certification of the 787 to deal with the fact that there is no "literal airgap" in recent airliners even though that was initially mandated by the airworthiness standards:

> These special conditions are issued for the Boeing Model 787-8 airplane. This airplane will have novel or unusual design features when compared to the state of technology envisioned in the airworthiness standards for transport category airplanes. The architecture of the Boeing Model 787-8 computer systems and networks may allow access to external systems and networks

[1] https://www.federalregister.gov/documents/2007/12/28/E7-2507...

Do you honestly believe your life depends on the stability of an in flight entertainment computer?

If your fellow passengers found out who killed the movies in the middle of a long flight... in this particular case, yes, it might.

It would probably not harm the aircraft but would be bad enough if it freezes the entertainment system for all passengers. If the ~300 other people on board find out that you're the one responsible for their boredom on a 10 hour flight, you won't have a great time.

Has anyone taken a 10h flight where the IFE was not rebooted due to some problem?

Agree the IFE could crash, but can't see how there is even a remote risk to critical systems, or any risk to the IFE that isn't solved by (yet another) reboot of it.

Reply on news.ycombinator.com