Feeds

Patched DNS servers still vulnerable to cache poisoning

But the sky won't fall just yet

Using blade systems to cut costs and sharpen efficiencies

Large swaths of the internet remain at risk from a potentially crippling vulnerability in the net's address lookup system even after installing emergency patches, a researcher has warned.

Russian researcher Evgeniy Polyakov posted exploit code here, which he says allowed him to poison domain-name system servers running the most recent version of the Berkeley Internet Name Domain (BIND), the most popular software for translating domain names into numeric IP addresses. The attack, which poisons the records of domain-name system servers with incorrect information, could allow criminals to silently redirect millions of users to fraudulent websites that attempt to steal login credentials or install malware.

Researchers who spearheaded an international push to get internet service providers and other large organizations to patch the flaw said they weren't terribly concerned about the exploit code. That's because Polyakov's attack took 10 hours to carry out using two machines connected directly to the targeted DNS server via a gigabit ethernet link.

"That's a little different then spending 10 seconds over the internet," to carry out an attack, said Dan Kaminsky, the researcher who first warned of the DNS cache poisoning vulnerability.

The original attack works by flooding a DNS server with thousands of requests for domains with slightly different variations, 1.google.com, 2.google.com, 3.google.com and so forth. That allows attackers to gain a secret transaction number needed to trick other computers into updating their records with IP addresses that lead to rogue websites.

Successful attacks took seconds to carry out using 10-megabit connections. The patch to BIND and other DNS programs randomizes the source ports used, vastly reducing the odds an attacker will gain the transaction credentials.

"We have successfully made the attack significantly less likely to occur in the real world," Kaminsky told The Register. "That doesn't mean the defense is perfect." He said the patch should be thought of as a "stopgap" until more thorough changes can be made to the net's DNS.

So a word to the Googles, Microsofts and Ciscos of the world: You dodged a bullet in surviving the Kaminsky bug with nary a scrape, but next time you may not be as lucky. Forging a real fix won't be easy, but it's essential. Time to get cracking. ®

Boost IT visibility and business value

More from The Register

next story
Secure microkernel that uses maths to be 'bug free' goes open source
Hacker-repelling, drone-protecting code will soon be yours to tweak as you see fit
How long is too long to wait for a security fix?
Synology finally patches OpenSSL bugs in Trevor's NAS
Roll out the welcome mat to hackers and crackers
Security chap pens guide to bug bounty programs that won't fail like Yahoo!'s
HIDDEN packet sniffer spy tech in MILLIONS of iPhones, iPads – expert
Don't panic though – Apple's backdoor is not wide open to all, guru tells us
Researcher sat on critical IE bugs for THREE YEARS
VUPEN waited for Pwn2Own cash while IE's sandbox leaked
Four fake Google haxbots hit YOUR WEBSITE every day
Goog the perfect ruse to slip into SEO orfice
Putin: Crack Tor for me and I'll make you a MILLIONAIRE
Russian Interior Ministry offers big pile o' roubles for busting pro-privacy browser
prev story

Whitepapers

Implementing global e-invoicing with guaranteed legal certainty
Explaining the role local tax compliance plays in successful supply chain management and e-business and how leading global brands are addressing this.
Consolidation: The Foundation for IT Business Transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.
Application security programs and practises
Follow a few strategies and your organization can gain the full benefits of open source and the cloud without compromising the security of your applications.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Securing Web Applications Made Simple and Scalable
Learn how automated security testing can provide a simple and scalable way to protect your web applications.