Air Gap FAILs, Configuration Mistakes Causing ICS/SCADA Cyberattacks

A utility's cautionary tale, and how a popular ICS/SCADA network protocol failed a fuzzing test miserably.

It had the markings of a possible sabotage operation. Stealthy, patient cyber attackers had wrested control of an ICS/SCADA controller in a power plant and were rooting around in what appeared to be a reconnaissance effort to map out the plant's infrastructure. The attackers were scanning for a specific type of PLM (product lifecycle management) controller when they unknowingly pinged a deception trap in place at the plant that blew their cover and ultimately alerted the security team.

Turns out the attackers' point of entry had been an open port in the compromised controller that inadvertently had been left open after a vendor-maintenance engagement. The attackers used that hole to to gain a foothold in the process control network and to tap the PLM controllers in order to map out the plant's operations.

"They took hold of a single device … and they were scanning for a specific kind of controller," says Ori Bach, vice president of products at TrapX, whose firm revealed the attack of its utility customer in a new report published today.

The report by TrapX, a security firm that specializes in so-called deception technology akin to advanced honeypots that act as lures for attackers, provides a glimpse of some real-world cyberattacks hitting ICS/SCADA networks in manufacturing and utility plant floors.

The utility – which TrapX declined to name – had installed the security vendor's deception product, which creates emulated servers, workstations, PLMs, and other devices as a way to detect attacks. The attackers had been gathering intel that could be used to help them disrupt the plant's operations or even damage it. The utility initially added the deception traps due to ransomware concerns.

The attackers gained access because of a failure to close the controller from outside access: "It was supposed to be shut down, but third-party maintenance for some reason left it open and the attackers were able" to exploit that, Bach notes.

Configuration mistakes are one of the most common ways attackers are infiltrating ICS/SCADA networks today, he says. Other common entry points for attackers are spear-phishing and bridging so-called air gapped systems, where an industrial network is isolated from other internal networks for security reasons but ends up either infected or open to the entire network via a a maintenance worker's laptop joining the plant floor network, or via an infected USB stick with maintenance software.

Security experts point to the aftermath of the 2003 power blackout in the Northeastern US that affected eight states, parts of Canada, and took two days to restore power to some 50 million people, as the turning point for ICS/SCADA vulnerability. The power industry went all out on resiliency and continuity to prevent another mass outage, adding remote monitoring and control of plants, basically exposing them to the Internet. "Unfortunately, by solving one problem, manufacturers have in fact exposed themselves to another. Critical infrastructure which was historically shielded due to isolation from the Internet is now at significant risk for cyber-attack," TrapX wrote in its report.

Tom Kellermann, CEO of Strategic Cyber Ventures, says this created a massive attack surface for ICS/SCADA systems. "They were told to overlay fiber optic networks with wireless," for example, he says. "The wide distribution of the smart grid is compounded by the tremendous amount of remote access allowed."

In the case of the power plant, the attackers had been inside for several weeks, but not long enough to do any actual damage to the plant. Even so, they gathered some information about the plant's layout and operations before they were spotted and removed.

"The power company is now moving from a perimeter security approach to a defense-in-depth approach. Now they have people and technology in the process that assume they will be breached and [that the breach] needs to be detected," Bach says. "They also added a lot more security people" and instituted more oversight of third-party vendor security and operations, he says, to prevent another misconfiguration misstep.

While human error-instigated security weaknesses are often the attacker's way in, many older ICS/SCADA systems and protocols come with their own set of vulnerabilities that an attacker can exploit.

ICS/SCADA network protocols didn't fare so well in a recent global fuzzing experiment by Synopsys: the IEC-61850 MMS network protocol used in ICS and Internet of Things networks crashed within an average of 6.6 seconds of the fuzzing test.

"ICS protocols haven't been as exposed to the Internet as much and not tested as much … But what we found was IEC within the first six seconds.

Robert Vamosi, security strategist with Synopsys, which yesterday published a fuzzing report of some 4.8 billion fuzz tests it conducted on customer sites in 2016.

Fuzzing is a longtime method of rooting out unknown security vulnerabilities that basically sends random inputs to the targeted software or protocol to see how it reacts. It's mostly used in conjunction with penetration testing. Synopsys found that MMS crashed within seconds of its fuzzer input, which was based on a template rather than random inputs. "We build our fuzzing around the RFCs and iterate off that," he says.

But just because a network protocol crashes in the fuzzing test doesn't necessarily confirm that there's an exploitable bug in the code. "Why it behaves badly requires additional investigating: not every vulnerability can be exploited. In some cases, you need a chain of them to make an active exploit," he says.

An attacker could wage a denial-of-service attack against MMS's vulnerability, he says, or insert malware when the software reboots after crashing, for example. "This could impact a SCADA system dramatically," he says.

Other network protocols in Synopsys' testing fared much better: TLS, the secure HTTPS protocol typically used for ecommerce and online banking, took on average nine hours to fall to the fuzzer.

Overall, the various network protocols fuzzed by Synopsys on average crashed within 1.4 hours. Interestingly, medical equipment and automobile network protocols landed in the middle of the pack in terms of most fuzzable. "ICS is the least mature" of the protocols, Vamosi says.

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About the Author(s)

Kelly Jackson Higgins, Editor-in-Chief, Dark Reading

Kelly Jackson Higgins is the Editor-in-Chief of Dark Reading. She is an award-winning veteran technology and business journalist with more than two decades of experience in reporting and editing for various publications, including Network Computing, Secure Enterprise Magazine, Virginia Business magazine, and other major media properties. Jackson Higgins was recently selected as one of the Top 10 Cybersecurity Journalists in the US, and named as one of Folio's 2019 Top Women in Media. She began her career as a sports writer in the Washington, DC metropolitan area, and earned her BA at William & Mary. Follow her on Twitter @kjhiggins.

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