The Insecurity of Secret IT Systems

We now know a lot about the security of the Rapiscan 522 B x-ray system used to scan carry-on baggage in airports worldwide. Billy Rios, director of threat intelligence at Qualys, got himself one and analyzed it. And he presented his results at the Kaspersky Security Analyst Summit this week.
It’s worse than you might have expected:

It runs on the outdated Windows 98 operating system, stores user credentials in plain text, and includes a feature called Threat Image Projection used to train screeners by injecting .bmp images of contraband, such as a gun or knife, into a passenger carry-on in order to test the screener's reaction during training sessions. The weak logins could allow a bad guy to project phony images on the X-ray display.

While this is all surprising, it shouldn’t be. These are the same sort of problems we saw in proprietary electronic voting machines, or computerized medical equipment, or computers in automobiles. Basically, whenever an IT system is designed and used in secret – either actual secret or simply away from public scrutiny – the results are pretty awful.
I used to decry secret security systems as "security by obscurity." I now say it more strongly: "obscurity means insecurity."
Security is a process. For software, that process is iterative. It involves defenders trying to build a secure system, attackers -- criminals, hackers, and researchers -- defeating the security, and defenders improving their system. This is how all mass-market software improves its security. It’s the best system we have. And for systems that are kept out of the hands of the public, that process stalls. The result looks like the Rapiscan 522 B x-ray system.
Smart security engineers open their systems to public scrutiny, because that’s how they improve. The truly awful engineers will not only hide their bad designs behind secrecy, but try to belittle any negative security results. Get ready for Rapiscan to claim that the researchers had old software, and the new software has fixed all these problems. Or that they’re only theoretical. Or that the researchers themselves are the problem. We’ve seen it all before.