Feeds

Patched DNS servers still vulnerable to cache poisoning

But the sky won't fall just yet

Top 5 reasons to deploy VMware with Tegile

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. ®

Beginner's guide to SSL certificates

More from The Register

next story
UK smart meters arrive in 2020. Hackers have ALREADY found a flaw
Energy summit bods warned of free energy bonanza
DRUPAL-OPCALYPSE! Devs say best assume your CMS is owned
SQLi hole was hit hard, fast, and before most admins knew it needed patching
Knock Knock tool makes a joke of Mac AV
Yes, we know Macs 'don't get viruses', but when they do this code'll spot 'em
Feds seek potential 'second Snowden' gov doc leaker – report
Hang on, Ed wasn't here when we compiled THIS document
Mozilla releases geolocating WiFi sniffer for Android
As if the civilians who never change access point passwords will ever opt out of this one
Why weasel words might not work for Whisper
CEO suspends editor but privacy questions remain
prev story

Whitepapers

Why and how to choose the right cloud vendor
The benefits of cloud-based storage in your processes. Eliminate onsite, disk-based backup and archiving in favor of cloud-based data protection.
A strategic approach to identity relationship management
ForgeRock commissioned Forrester to evaluate companies’ IAM practices and requirements when it comes to customer-facing scenarios versus employee-facing ones.
High Performance for All
While HPC is not new, it has traditionally been seen as a specialist area – is it now geared up to meet more mainstream requirements?
Saudi Petroleum chooses Tegile storage solution
A storage solution that addresses company growth and performance for business-critical applications of caseware archive and search along with other key operational systems.
Choosing a cloud hosting partner with confidence
Download Choosing a Cloud Hosting Provider with Confidence to learn more about cloud computing - the new opportunities and new security challenges.