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By those definitions, a refinery whose control systems ensure it can never explode, but allow anyone with internet access to override anything, is insecure but
by mikeash 8y ago
By those definitions, a refinery whose control systems ensure it can never explode, but allow anyone with internet access to override anything, is insecure but perfectly safe. Yet the result is explosions and dead people. That doesn't make sense.
- gmueckl 8y agoNo, it does make perfect sense in a way. Safety in these terms means that things are extremely unlikely to go wrong by themselves. Interventions are simply not a part of that model. There is some, but not a lot of awareness in the industry that the implicit trust between components in these systems is insecure and ultimately jeopardizes their safety. It is too easy to spoof process values that are sane, but do not reflect the true state of the system. The systems fundamentally miss any mutual authentication between their components. Process measurement devices typically even offer a simulation mode in their firmware to do just that. At worst, all you have to do is to crack a simple password to gain access to this feature remotely.