DNS remains vulnerable one year after Kaminsky bug

Cache poisoning attacks rise amid scramble to patch DNS servers, deploy security add-on

A year has passed since security researcher Dan Kaminsky disclosed a serious flaw in the DNS that makes it possible for hackers to launch cache poisoning attacks, where traffic is redirected from a legitimate Web site to a fake one without the Web site operator or end user knowing.

Kaminsky's disclosure was a wake-up call to network vendors and ISPs about the inherent weaknesses in DNS, the foundational Internet standard that matches IP addresses with domain names.

The hype around Kaminsky's discovery also gave a much-needed boost to DNS Security Extensions (DNSSEC), an add-on security mechanism that had been languishing due to a lack of demand by network managers.

Kaminsky "helped raise awareness of the DNS vulnerability but also of Internet security in general and how dependent we are on protocols that don't have security built in," says Scott Rose, a computer scientist with the National Institutes of Standards and Technology and an expert in DNS security.

"There was discussion always in the protocol community about the vulnerability of DNS and the need for DNSSEC deployment, but the issue did get a big boost from the outside" thanks to Kaminsky, Rose said. "He raised the issue of what can happen when you attack the DNS. It's not just about redirecting browsers but subverting e-mail. All the other attacks that Kaminsky outlined brought the issue to the forefront."

Experts say more has been done to bolster the security of the DNS in the past 12 months than in the previous decade, thanks to Kaminsky's discovery. Yet, the DNS remains as vulnerable as ever to cache poisoning attacks.

The Kaminsky bug "was a big deal for the Internet community at large," says Joe Gersch, Chief Operating Officer at Secure64, which sells DNS server software and automated tools for migrating to DNSSEC. Gersch was at the Black Hat conference last summer when Kaminsky detailed the DNS cache poisoning threat in front of a standing-room-only crowd.

"It took 20 minutes for Kaminsky to explain how it works, and then he went through case after case of how it could be exploited for another hour and a half," Gersch says. "He showed how once you own the DNS, you own everything. And he showed how insidious the flaw is so that you don't even know you've been compromised. Jaws were dropping."

Gersch says Kaminsky did more than raise awareness of the inherent lack of security in DNS. "It was a pretty big call to action, first for the patch and then for ... DNSSEC deployment," Gersch says.

Since then, most -- but not all -- network engineers have patched their DNS servers against the Kaminsky bug. Patching is what Kaminsky recommends as a short-term fix to this vulnerability.

The long-term fix for Kaminsky-style attacks is DNSSEC, which prevents cache poisoning attacks by allowing Web sites to verify their domain names and corresponding IP addresses using digital signatures and public-key encryption.

The problem is that DNSSEC works best when it is fully deployed across the Internet: from the root zone at the top of the DNS heirarchy, to individual top-level domains such as .com and .net, down to individual domain names. Until that happens, Web sites remain vulnerable to Kaminsky-style attacks.

The Kaminsky flaw is "the prime driver for DNSSEC," says Rodney Joffe, senior vice president and senior technologist with NeuStar, which sells managed DNS services and an interim fix to cache poisoning attacks called Cache Defender. The problem, Joffe says, is that "we're still a year or more away from DNSSEC deployment."

Join the CSO newsletter!

Error: Please check your email address.

Tags dns flawKaminsky

More about EircomFacebookNeuStarRoseSECVeriSign Australia

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Carolyn Duffy Marsan

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts