Despite Stuxnet, Duqu, control system flaws still overlooked

Computerworld - Efforts to strengthen critical infrastructure targets continue to focus on front-end systems rather than on underlying industrial control systems where the real problems exist, security experts warned this week.

The Stuxnet worm that last year showed how flaws in control systems can be exploited to cause damage to physical assets, but it hasn't yet led to significant security upgrades, they contended.

"Everyone keeps focusing on PCs while PLCs (programmable logic controllers) are still in the same state they were 10 years ago," said Dale Peterson, CEO of Digital Bond, a consulting firm specializing in control system security.

The issue has been longstanding within the industrial control system (ICS) community, and surfaced again this week with the release of a Symantec report that the new Duqu Trojan has links to Stuxnet.

According to Symantec, the Duqu worm appears have been built to steal critical information from vendors of industrial control systems.

Unlike Stuxnet, Duqu does not directly target industrial control systems though information it gathers could be used to create the next Stuxnet, Symantec warned.

The report reignited fears about cyberattacks targeted at the control systems behind equipment at critical infrastructure such as power plants, water treatment facilities and chemical plants.

The problem, though, is that the concerns so far have focused on the front-end, mostly Windows-based Human Machine Interface (HMI) systems that are used to interact with control systems, Peterson said.

Many flaws that have been described as control systems flaws have really been at the front-end engineering workstation layer.

For example last month, Italian researcher Luigi Auriemma disclosed several zero-day vulnerabilities in Supervisory Control and Data Acquisition (SCADA) products from multiple vendors including Rockwell Automation, Cogent Datahub, Measuresoft and Progea.

Earlier this year, Auriemma had disclosed similar flaws in products from Siemens, Iconics, 7-Technologies and Datac. Most of the flaws were at the HMI layer.

"There are vulnerabilities in all components but HMI [flaws] are the easiest for researchers to get their hands on," Peterson said.

While addressing such flaws is vital, it is equally important to address flaws in the control systems themselves, said Joseph Weiss, managing partner at Applied Control Systems LLC and author of the book Protecting Industrial Control Systems from Electronic Threat. "These are the flaws that can cause things to go boom at night."

"If you haven't protected HMI's, shame on you," Weiss said. But the bigger threats really are the control system flaws that allow attackers to send commands that cause physical equipment to shut down, overheat or blow-up, he added.

Stuxnet showed how programmable logic controllers could be overwritten to send commands that caused equipment to fail, he said. Despite that warning, little has changed. "Prior to Stuxnet there were zero programs for securing PLCs. To this day there are no programs for securing PLCs," Weiss said.