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LAS VEGAS--Networking giant Cisco and security company Internet Security Systems filed on Wednesday a restraining order against the management of the Black Hat Conference and a security expert who told conference attendees that attackers can broadly compromise Cisco routers.
The legal action followed a presentation by security researcher Michael Lynn, a former ISS employee, who brushed off threats of legal action and a broad effort to delete his presentation from conference materials to warn attendees that malicious programs could be run on Cisco routers.
While the information had already been presented by Lynn, a Cisco spokesman said that the companies wanted to prevent further dissemination of inside information about Cisco's routers.
"We don't want them to further discuss it," said Cisco spokesman John Noh. "This is about protecting our intellectual property."
Three weeks of intense discussions between ISS, the researcher, Cisco, and conference management failed on Wednesday. Two days before, Cisco representatives spent eight hours ripping out the ten-page presentation from the conference book and ISS executives decided to pull the presentation, allowing researcher Lynn to speak on a different topic.
In a dramatic reversal on Wednesday, Lynn told attendees he tendered his resignation to ISS less than two hours before he went on stage to present his findings, then proceeded to describe a reliable way to run programs by exploiting the Internet Operating System (IOS), the core software for Cisco routers.
"I feel I had to do what's right for the country and the national infrastructure," he said. "It has been confirmed that bad people are working on this (compromising IOS). The right thing to do here is to make sure that everyone knows that it's vulnerable."
A majority of the Internet infrastructure relies on Cisco networking hardware to route data from one computer to another. While security researchers have found flaws in the IOS router software in the past, almost all the vulnerabilities have only allowed an attacker to degrade communications in what is known as a denial-of-service attack.
Lynn outlined a way to take control of an IOS-based router, using a buffer overflow or a heap overflow, two types of memory vulnerabilities. He demonstrated the attack using a vulnerability that Cisco fixed in April. While that flaw is patched, he stressed that the attack can be used with any new buffer overrun or heap overflow, adding that running code on a router is a serious threat.
"When you attack a host machine, you gain control of that machine--when you control a router, you gain control of the network," Lynn said.
ISS disavowed any foreknowledge of Lynn's intent to resign and present his findings. Cisco condemned the talk in strong terms that suggested the company may initiate legal action against the researcher and the conference, describing the presentation as the illegal publication of proprietary material.
"It is especially regretful, and indefensible, that the Black Hat Conference organizers have given Mr. Lynn a platform to publicly disseminate the information he illegally obtained," the company said in a statement. "We appreciate the cooperation we have received from ISS in this matter. We are working with ISS to continue our joint research in the area of security vulnerabilities."
For his part, Black Hat Conference organizer and founder Jeff Moss denied that he had any idea of Lynn's intent.
"He told me yesterday that he would do his backup presentation," Moss said after the controversial presentation. Moss said he had worked hard to address Cisco's concerns with the original presentation. "We were in the middle of trying to run a conference and lawyers from Cisco were talking about a temporary restraining order."
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."
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