The controversy is the latest rift between security researchers who find vulnerabilities and the software companies whose products contain the flaws. Last week, researchers at Red Database Security took Oracle to task for waiting more than two years to fix vulnerabilities. In April, UK-based researchers weathered legal threats from Sybase to negotiate an agreement in order to release details of several flaws in that company's database.
In the latest case, ISS and Lynn contacted Cisco in April to report their process for using a vulnerability in IOS to run a program on a Cisco router. The networking fixed the vulnerability in the operating system, but did nothing to prevent attackers from running programs on the devices using the broad techniques Lynn described, the researcher said.
During his presentation, Lynn outlined an eight step process using any known, but unpatched flaw, to compromise a Cisco IOS-based router. While he did not publish any vulnerabilities, Lynn said that finding new flaws would not be hard.
"People aren't looking at this because they don't think gaining control of a router is doable, but there are a lot of bugs to find," he said.
Executives from Internet Security Systems defended their decision to cancel the session. The presentation had been pulled because it was "incomplete," said Chris Rouland , chief technology officer for the Altanta, Georgia-based company.
"We had been working with Cisco to explore the viability of exploitation of older IOS vulnerabilities," Rouland said. "We felt that we had done as much as we could on our own and needed to approach Cisco."
Both Cisco and ISS recommended that customers update their router software on a regular basis. Moreover, the sheer number of different models of routers and gateways makes it more difficult for an attacker to create an exploit to work against them all.
In a presentation that had all the hallmarks of good theater, Lynn stated several times that the information that he was presenting would likely result in legal action against him.
"What I just did means that I'm about to get sued by Cisco and ISS," Lynn said, joking later that he may be "in Guantanamo" by the end of the week.
However, Lynn argued that the seriousness of the attack left him no choice but to let people know the existence of the weakness in the software. Cisco plans in the future to abstract the architecture of the router operating system in the future, which could have a side effect of making a single attack work against all routers. Rather then knowing the various memory addresses, or offsets, needed to compromise systems, a single offset could work, Lynn said.
"What politicians are talking about when they talk about the Digital Pearl Harbor is a network worm," he said. "That's what we could see in the future, if this isn't fixed."