DNS Flaw Is A Serious Security Threat

from the patch-those-servers dept

Aaron Massey has a good write-up of the DNS vulnerability that was discovered by security researcher Dan Kaminsky and leaked onto the Internet this week. In a nutshell, a flaw in the design of the DNS protocol (which translates domain names like "techdirt.com" to IP addresses) will make it possible for malicious individuals to invisibly redirect web traffic from legitimate sites to sites of the attacker's choosing. This is a huge deal because a ton of online applications and services depend on reliable DNS for their security. You might think you're visiting your bank's website, but if your DNS server isn't patched you could really be sending your password to hackers in Russia. Kaminsky tells Wired that fewer than half of the DNS servers on the Internet were patched when the details of the vulnerability leaked, so it's a real problem. If your ISP hasn't patched its DNS servers, you can protect yourself by switching to OpenDNS until they do so.

There's a long-running argument in computer security circles about the best way to release information about security vulnerabilities, with a lot of security professionals favoring immediate, public disclosure of all vulnerabilities. Kaminsky chose not to go the public disclosure route because he felt this bug was too serious to take the risk of its being misused. Kaminsky approached the major DNS vendors in March, and managed to keep the details secret long enough for them to develop fixes for their products. Then, on July 8, Kaminsky announced the simultaneous release of these fixes, while still keeping the details of the vulnerability secret. (The fixes worked in a general enough way that they didn't give away the details of the vulnerability.) He had been intending to keep it secret until August 8, so that systems administrators would have a full month to prepare their networks. Unfortunately, the information leaked out on Monday, leading to a scramble to patch the remaining DNS servers before exploits start showing up. Given the scope of the patching effort (16 people from various organizations were invited to the secret March summit among DNS vendors), I think it's pretty impressive that the details didn't leak out earlier.

Filed Under: disclosure, dns flaw, security