SCADA, or Supervisory Control And Data Acquisition, security breaches are not often heard about. At least, not at the same level of other sorts of computer crimes. But SCADA has the potential to impact the physical environment, physical security, and personal safety of all of us, so such incidents should not be taken lightly.
For those who are unfamiliar with SCADA, it’s basically about computer systems and networks that monitor and control industrial, infrastructure, or facility-based processes. For example, SCADA systems are used to manage and operate power generation plants or water treatment plants. In buildings, SCADA can be behind the operation of electrical systems, elevator controls, air-conditioning systems, etc.
SCADA was not built with very much security at the beginning. This is not unlike how our various Internet protocols weren’t very secure either in the early ages of the Internet. Much of SCADA security used to depend on its physical interconnections being “physically secure”. The scary thing is that SCADA systems are now often linked, or are converged, with computer data networks, and you know how that makes it so much more convenient for the bad guys to penetrate and disrupt SCADA systems.
While in the past, the logic controls of various processes were often hard-wired into the devices and control systems themselves, nowadays much of the monitoring and control are centralized and remotely managed through SCADA.
Let me illustrate with an example. An old failover air-con system might be designed with hard-wired electrical or mechanical controls. If the main air-con fails to maintain room temperature, a thermostat will start up a standby air-con once the temperature breaches a certain threshold. This is old school. With intelligent building controls, sensors deliver data to a central computer system which decides, and then, sends out a command signal to start the standby air-con. This sounds quite uninteresting, and perhaps you don’t see how it can lead to serious safety problems. But, imagine, if this hard-wired mechanism were, instead, a safety system that opens a release valve of a chamber when its internal pressure breaches a certain threshold. Let’s say it’s now replaced by a SCADA network, managed by a remote computer system. A malicious hacker gets in and alters the control program or sabotages the computer so that it never sends the command to open the safety valve. If pressure builds up and there’s no way to relief it, then eventually the chamber will break and explode.
I’m surprised that the blackout at Marina Bay Sands had to do with misuse of SCADA systems. An insider had, while accessing the system remotely, caused the blackout. More interesting is how the people on-site could not rectify the problem, and that the police had to be called to compel that person to cooperate, before the blackout was rectified. Although this incident was a big embarrassment to Marina Bay Sands, it didn’t really have any real threat to people’s safety.
But considering what SCADA system can be used for, it is worrying how, when, and what the next SCADA breach might result in. It’s high time for SCADA users to seriously rethink how their systems are used, and to ensure appropriate safeguards and fail-proof capabilities and built in.