Cured DNS hack makes a surprising comeback

Zero-day attack
(Image credit: Shutterstock.com)

Security researchers have managed to exploit an old vulnerability in the implementation of the Domain Name System (DNS) to override safeguards and reanimate an attack that was killed in 2008.

As per the group of researchers from Tsinghua University and UC Riverside, the vulnerability affects a majority of the popular DNS services, including Google’s 8.8.8.8 and CloudFlare’s 1.1.1.1.  

The good news however is that before making their findings public, the researchers privately shared their findings with DNS providers and software developers, many of whom have implemented a fix to mitigate the vulnerability.

Name your poison

Dan Kaminsky first highlighted a major shortcoming in the implementation of the DNS protocol in 2008. When exploited it would send visitors to malicious websites instead of the ones they typed into their web browser windows.

Kaminsky’s DNS cache poisoning attack sent everyone scurrying for a solution and the reputable DNS providers soon implemented a fix. 

That was until security researchers presented a novel approach to side step the fix and make it possible to send traffic to malicious IP addresses once again.

In simple terms, the solution to Kaminsky’s attack was to randomize the number of the source port sending the DNS request. The new attack, dubbed SAD (Side channel AttackeD) DNS cleverly derandomizes the source port. 

The research was presented at the 2020 ACM Conference on Computer and Communications Security. The researchers also have a website for the new attack where they share more details and allow you to test whether your DNS resolver is vulnerable.

Source: ArsTechnica

Mayank Sharma

With almost two decades of writing and reporting on Linux, Mayank Sharma would like everyone to think he’s TechRadar Pro’s expert on the topic. Of course, he’s just as interested in other computing topics, particularly cybersecurity, cloud, containers, and coding.

Latest in Website Hosting
cybersecurity
What's the right type of web hosting for me?
A cloud symbol imposed over a bank of servers in a data center.
What is cloud hosting and who needs it?
Minecraft game server hosting for streamers heading - The Minecraft logo above a Minecraft landscape.
I tried 15 hosts for streaming and hosting Minecraft games and these are the best
Dark web scanning on a laptop
Hostinger integrates dark web scanning into hPanel
WordPress
WordPress Foundation bid for greater trademark control halted, adding to more legal setbacks for CEO Matt Mullenweg
The PebbleHost website.
PebbleHost review
Latest in News
Ray-Ban Meta Smart Glasses
Samsung's rumored smart specs may be launching before the end of 2025
Apple iPhone 16 Review
The latest iPhone 18 leak hints at a major chipset upgrade for all four models
Quordle on a smartphone held in a hand
Quordle hints and answers for Monday, March 24 (game #1155)
NYT Strands homescreen on a mobile phone screen, on a light blue background
NYT Strands hints and answers for Monday, March 24 (game #386)
NYT Connections homescreen on a phone, on a purple background
NYT Connections hints and answers for Monday, March 24 (game #652)
Quordle on a smartphone held in a hand
Quordle hints and answers for Sunday, March 23 (game #1154)