Capacity planning with a virtualized network is “going to be very difficult to predict,” Hoff said, adding he was profoundly skeptical that trying to virtualize a firewall is going to work as DMZs are pushed into going virtual, too.

“If I decide to V-motion a firewall, it won’t work,” said Hoff, alluding to his own research with VMware and its V-Motion capability to rapidly deploy VM images. With virtualization, “you won’t get rid of host-based security software. As we add more solutions, we add complexity,” Hoff said, advising the Black Hat audience “not to be dragged into the environment.”

The Cisco factor

While virtualization got its fair share of attention, it wouldn’t be a Black Hat conference without Microsoft and Cisco being bandied about. But this year experts said with Microsoft Windows no longer the fertile ground for bug hunting that it once was, researchers are looking at other products to hack. And Cisco’s routers are an interesting target. They command more than 60 percent of the router market, according to research firm IDC.

“If you own the network, you own the company,” said Nicolas Fischbach, senior manager of network engineering and security with COLT Telecom, a European data service provider. “Owning the Windows PC is not really a priority anymore.”

But Cisco’s routers make a harder target than Windows. They’re not as well-known to hackers and they come in many configurations, so an attack on one router might fail on a second. Another difference is that Cisco administrators are not constantly downloading and running software. Cisco has done a lot of work in recent years to cut down on the number of attacks that can be launched against its routers from the Internet, according to Fischbach. “All the basic, really easy exploits you could use against network services are really gone,” he said. The risk of having a well-configured router hacked by someone from outside of your corporate network is “really low.”

That hasn’t deterred the latest crop of security researchers.

Two months ago Core Security researcher Sebastian Muniz showed new ways of building hard-to-detect rootkit programs for Cisco routers, and last week his colleague, Ariel Futoransky, gave an update on the company’s research in this area. Also, two researchers from Information Risk Management (IRM), a security consultancy, released a modified version of the GNU Debugger which gives hackers a view of what happens when Cisco IOS software processes their code, and three shell-code programs that can be used to control a Cisco router.