New York: Since a secret emergency meeting of computer security experts at Microsoft’s headquarters in March, Dan Kaminsky has been urging companies around the world to fix a potentially dangerous flaw in the basic plumbing of the Internet.
While Internet service providers are racing to fix the problem, which makes it possible for criminals to divert users to fake websites where personal and financial information can be stolen, Kaminsky worries that they have not moved quickly enough.
By his estimate, roughly 41% of the Internet is still vulnerable. Now Kaminsky, a technical consultant who first discovered the problem, has been ramping up the pressure on companies and organizations to make the necessary software changes before criminal hackers take advantage of the flaw.
Next week, he will take another step by publicly laying out the details of the flaw at a security conference in Las Vegas. That should force computer network administrators to fix millions of affected systems.
But his explanation of the flaw will also make it easier for criminals to exploit it, and steal passwords and other personal information.
Kaminsky walks a fine line between protecting millions of computer users and eroding consumer confidence in Internet banking and shopping. But he is among those experts who think that full disclosure of security threats can push network administrators to take action. “We need to have disaster planning, and we need to worry,” he said.
The flaw that Kaminsky discovered is in the domain name system, a kind of automated phone book that converts human-friendly addresses such as Google.com into machine-friendly numeric counterparts.
Ensuring safety: Dan Kaminsky, a director at IOActive, a computer security firm
The potential consequences of the flaw are significant. It could allow a criminal to redirect Web traffic secretly, so that a person typing a bank’s actual Web address would be sent to an impostor site set up to steal the user’s name and password.
The user might have no clue about the misdirection, and unconfirmed reports in the Web community indicate that attempted attacks are already under way.
The problem is analogous to the risk of phoning directory assistance at, for example, AT&T, asking for the number for Bank of America and being given an illicit number at which an operator masquerading as a bank employee asks for your account number and password.
The online flaw and the rush to repair it are an urgent reminder that the Internet remains a sometimes anarchic jumble of jurisdictions.
No single person or group can step in to protect the online transactions of millions of users. Internet security rests on the shoulders of people like Kaminsky, a director at IOActive, a computer security firm, who had to persuade other experts that the problem was real.
“This drives home the risk people face, and the consumer should get the message,” said Ken Silva, chief technology officer of VeriSign, which administers Internet addresses ending in .com and .net. “Don’t just take for granted all the things that machines are doing for you.”
When Kaminsky, 29, announced the flaw on 8 July, he said he would wait a month to release details about it, in the hope that he could spur managers of computer systems around the world to fix them with a software patch before attackers could figure out how to exploit it.
Last week, however, accurate details of the flaw were briefly published online by a computer security firm, apparently by accident. Now security experts are holding their breath to see whether the patching of as many as nine million affected computers around the world will happen fast enough.
“People are taking this pretty seriously and patching their servers,” Silva said. Major Internet service providers in the US this week indicated that in most cases, the software patch, which makes the flaw much more difficult to exploit, was already in place or soon would be.
Comcast and Verizon, two of the largest providers, said they had fixed the problem for their customers. AT&T said it was in the process of doing so.
But the problem is a global one, and the length of time required to fix it could leave many Web users vulnerable for weeks or months. And there are millions of places around the world where people might find themselves vulnerable to potential attacks, ranging from their workplaces to an airport lounge or an Internet café.
Individuals and small companies with some technical skills can protect themselves by changing the network preferences of their computer settings so that they use the domain name servers of a Web service called OpenDNS (www.opendns.com).
Some computer systems are immune to the flaw. About 15% of domain name servers in the US and 40% in Europe, including those at major Internet providers such as America Online and Deutsche Telekom, use software from a Dutch company called PowerDNS, which is not vulnerable.
Still, much of the Internet remains vulnerable. “I’m watching people patch, and I realize this is not an easy thing to do,” Kaminsky said in an interview.
The flaw, which Kaminsky stumbled across in February, had been overlooked for more than two decades. The eureka moment came when he was idly contemplating a different security threat. He suddenly realized that it would be possible to guess crucial information about the protocol that domain name servers use to convert the numerical Web addresses.
Kaminsky worried about his discovery for several days and then contacted Paul Vixie, a software engineer who runs the Internet Systems Consortium and is responsible for maintaining a widely used version of software for domain name servers, known as BIND. Almost immediately, software engineers who looked at the vulnerability realized that Kaminsky had found a significant weakness.
In March, Microsoft held the secret meeting at its headquarters in Redmond, Washington. Sixteen representatives from security organizations and companies, including Cisco, talked about ways to combat the potential threat.
But after several delays while vendors fixed their software, Kaminsky went public.
For Kaminsky, the discovery and his subsequent warning to the Internet community were the culmination of an almost decade-long career as a security specialist. He was spotting bugs in software for Cisco and contributing to a book on computer security while still in college.
“I play this game to protect people,” he said.
He thinks that it is necessary to publish information about security threats to motivate system operators to protect themselves. Otherwise, “You don’t get to tell the river you need more time until it floods,” he said.
He said that he had initially hoped to give the Internet community a head start of a full month to fix the problem, but his plan was foiled when technical details were briefly posted online last week. “I would have liked more time, but we got 13 days and I’m proud of that,” he said.
The new flaw has sharpened the debate over how to come up with a long-term solution to the broader problem of the lack of security in the domain name system, which was invented in 1983 and was not created with uses such as online banking in mind.
While Kaminsky is being hailed as a latter-day Paul Revere, Internet experts such as Bruce Schneier, a member of the insular community that guards online security, said flaws like this were a routine occurrence and no reason to stay off the Internet.
“If there is a flaw in your car, it will get fixed eventually,” said Schneier, the chief security technology officer for British Telecom. “Most people keep driving.”
©2008/THE NEW YORK TIMES