More Fixes Needed, Says Finder of DNS Flaw

Dialing Down the Squabbles

Kaminsky today downplayed some of the early skepticism expressed by some researchers about the seriousness of the issue. He stressed that contrary to what some might believe, the vulnerability he discovered is indeed new -- and unprecedented in its seriousness.

"It's a new flaw, it changes the rules," Kaminsky warned today. "We have known for years that we have been in trouble with this transaction ID size. Why we are in trouble is going to become apparent very soon. This is absolutely something new and very scary," he said, while reiterating earlier pleas for IT managers to immediately patch their name servers.

He added that some of the skepticism stems from the fact that people are being asked to believe that the flaw is very serious without being given any proof of that till now. "I know that's very unusual. But if this thing isn't off the charts, I would have caused a huge amount of press for nothing," he added.

Echoing Kaminsky's caution was Cricket Liu, a DNS expert and vice president of architecture at Infoblox, a provider of domain name resolution, IP address assignment and other services. Speaking with Computerworld after today's press conference, Liu said the current round of patches buys some time, but more permanent fixes are needed down the road.

He noted that this is not the first time that DNS vulnerability issues have come to the fore. The first cache-poisoning attack in fact was demonstrated as far back as 1997 and took advantage of an implementation flaw in the widely used Berkeley Internet Name Domain (BIND) implementation of DNS. More recently, a similar cache-poisoning flaw was discovered in Open BSD's Pseudo-Random Number Generator (PRNG) function. Each time patches were issued for the problems and "we thought we were in better shape then," Liu said. "And then Dan (Kaminsky) came out with his bug," he said.

He reiterated Kaminksy's call for companies to immediately patch their DNS servers to avoid the risk of their Internet traffic and emails being hijacked and added that the kind of attacks that are possible as a result of the flaw are easier to mount that many might assume.