The computer security researcher who revealed a serious vulnerability in the operating system for Cisco Systems routers this year says he discovered 15 additional flaws in the software that have gone unreported until now, one of which is more serious than the bug he made public last summer.
Mike Lynn, a former security researcher with Internet Security Systems, or ISS, said three of the flaws can give an attacker remote control of Cisco's routing and gateway hardware, essentially allowing an intruder to run malicious code on the hardware. The most serious of the three would affect nearly every configuration of a Cisco router, he said.
"That's the one that really scares me," Lynn said, noting that the bug he revealed in July only affected routers configured in certain ways or with certain features. The new one, he said, "is in a piece of code that is so critical to the system that just about every configuration will have it. It's more part of the core code and less of a feature set," Lynn said.
Lynn, who now works for Cisco competitor Juniper Networks, told Wired News that ISS has known about additional flaws in the Cisco software for months but hasn't told Cisco about them. This is serious, Lynn said, because attackers may already be developing exploits for the vulnerabilities. Cisco's source code was reportedly stolen in 2004 and, while doing research on the IOS software, Lynn found information on a Chinese-language website that indicated to him that Chinese attackers were aware of the security flaws in IOS and could be exploiting them.
"Essentially there are more bugs, and they've gagged me from telling anyone the details of what they are," Lynn said.
"It's pretty meticulous. There's lots of notes because it's very complicated stuff," Lynn said. "I gave the most details for the ones that are the most critical -- those are all spelled out."
With regard to Allor's statement suggesting that any flaws ISS found are theoretical, Lynn said, "We're not dealing with an iffy thing when I actually have the code that I'm disassembling."
"At the very least," he said, "even if ISS only suspected there were flaws, you'd think they'd want to talk to Cisco about it even if they think maybe it's not true. If I'm totally wrong, great, but I have a pretty good track record on this, and you'd think they'd want to be talking to Cisco to be sure."
This story is far from over. I continue to keep my fingers crossed that we don't see a router worm hit the net.