The Surprising Security Threat: Your Printers

Computerworld - The Blaster worm hit McCormick and Co. hard and fast. It entered the famous spice company through a service provider connection and ripped across plants and offices in a matter of hours. What was most vexing, however, was that the virus kept coming back on disinfected network segments.

Upon further investigation, it turned out that Blaster, as well as some instances of the Sasser worm, were trying to repropagate from infected network printers.

“Printers were just one of several types of systems contributing to the nightmare at the time,” says Michael Rossman, who’d just taken over as global director of IT services and information security at McCormick at the time of the worm outbreak in 2003. “Blaster went to all our PCs, our radio frequency units, our handhelds. And, we learned belatedly, it also spread to our printers.”

Blaster and Sasser gave IT execs some religion about the vulnerabilities network printers can introduce to corporate networks, Rossman says. Since then, however, there has been little evidence of printer-based attacks spreading across large networks. Corporate IT shops haven’t been concerned about printer security. Instead of patching and hardening printers, they have been complacent. Security experts say that printers are loaded with more complex applications than ever, running every vulnerable service imaginable, with little or no risk management or oversight.

If these systems aren’t hardened, users may soon find their printers rendered inaccessible by attackers, their valuable documents heisted or their printers turned into remote-controlled bots — launching pads for further attacks.

The problem, of course, is that printers aren’t on the agendas of many security managers. “It’s been my experience that these devices have been completely overlooked from a risk management perspective,” says security researcher Brendan O’Connor. “They’re installed. They work. And nobody pays them any attention until it’s time to install a new paper tray or print cartridge.”

Not So Dumb

In essence, networked printers need to be treated like servers or workstations for security purposes — not like dumb peripherals.

At the Black Hat conference in Las Vegas in August, O’Connor delivered a blow-by-blow presentation on how to bypass authentication, inject commands at the root level and create shell code to take over printers in Xerox Corp.’s WorkCentre line of printers, which run on Linux operating systems.