New Siemens SCADA Vulnerabilities Kept Secret
SCADA systems -- computer systems that control industrial processes -- are one of the ways a computer hack can directly affect the real world. Here, the fears multiply. It's not bad guys deleting your files, or getting your personal information and taking out credit cards in your name; it's bad guys spewing chemicals into the atmosphere and dumping raw sewage into waterways. It's Stuxnet: centrifuges spinning out of control and destroying themselves. Never mind how realistic the threat is, it's scarier.
Last week, a researcher was successfully pressured by the Department of Homeland Security not to disclose details "before Siemens could patch the vulnerabilities."
Beresford wouldn't say how many vulnerabilities he found in the Siemens products, but said he gave the company four exploit modules to test. He believes that at least one of the vulnerabilities he found affects multiple SCADA-system vendors, which share "commonality" in their products. Beresford wouldn't reveal more details, but says he hopes to do so at a later date.
We've been living with full disclosure for so long that many people have forgotten what life was like before it was routine.
Before full disclosure was the norm, researchers would discover vulnerabilities in software and send details to the software companies -- who would ignore them, trusting in the security of secrecy. Some would go so far as to threaten the researchers with legal action if they disclosed the vulnerabilities.
Later on, researchers announced that particular vulnerabilities existed, but did not publish details. Software companies would then call the vulnerabilities "theoretical" and deny that they actually existed. Of course, they would still ignore the problems, and occasionally threaten the researcher with legal action. Then, of course, some hacker would create an exploit using the vulnerability -- and the company would release a really quick patch, apologize profusely, and then go on to explain that the whole thing was entirely the fault of the evil, vile hackers.
I wrote that in 2007. Siemens is doing it right now:
Beresford expressed frustration that Siemens appeared to imply the flaws in its SCADA systems gear might be difficult for a typical hacker to exploit because the vulnerabilities unearthed by NSS Labs "were discovered while working under special laboratory conditions with unlimited access to protocols and controllers."
There were no "'special laboratory conditions' with 'unlimited access to the protocols,'" Beresford wrote Monday about how he managed to find flaws in Siemens PLC gear that would allow an attacker to compromise them. "My personal apartment on the wrong side of town where I can hear gunshots at night hardly defines a special laboratory." Beresford said he purchased the Siemens controllers with funding from his company and found the vulnerabilities, which he says hackers with bad intentions could do as well.
That's precisely the point. Me again from 2007:
Unfortunately, secrecy sounds like a good idea. Keeping software vulnerabilities secret, the argument goes, keeps them out of the hands of the hackers.... But that assumes that hackers can't discover vulnerabilities on their own, and that software companies will spend time and money fixing secret vulnerabilities. Both of those assumptions are false. Hackers have proven to be quite adept at discovering secret vulnerabilities, and full disclosure is the only reason vendors routinely patch their systems.
With the pressure off, Siemens is motivated to deal with the PR problem and ignore the underlying security problem.
Posted on May 24, 2011 at 5:50 AM • 68 Comments