Sure, but how likely is this in this specific scenario. We’re talking about a system that’s not even directly controlling the train but just a display on it. The worst that can happen is that those displays won’t work until the system is reinstalled. That’s hardly a lucrative target for modern hackers. There’s way easier target which are worth something.
I’m not talking about this specific instance, just that block of misinformation/generalisation. Saying that legacy systems are well-secured because they’re “battle tested” is sheer ignorance.
Take side-channel attacks for example. A timing attack is something programmers from the 60’s and 70’s would not have taken into account when writing their hashing algorithms. And speaking of hashing, what hashing algorithms were available back then? CRC32 or something similar? What about salting? You get the idea.
Not to mention that legacy operating systems don’t get security updates. Let’s assume that DOS is secure (which it definitely isn’t), but if that statement were correct, would it apply to Windows XP as well?
All I’m saying is that the article is dead wrong. As software developers in this century, we’ve come a long way. We’ve developed security best practices, written libraries and frameworks, and come up with mitigations for a lot of these security vulnerabilities. These solutions are something that closed-source legacy systems (and anything without active maintenance) would never benefit from.