Apple update finally fixes important DNS bug

Apple has patched a flaw in the DNS software used by Mac OS X.

Apple has released a security update for its Mac OS X operating system, fixing a critical Internet security flaw that the company had failed to properly patch in late July.

The Mac OS X v. 10.5.5 security update was released Monday, fixing security bugs in Apple's software as well as several open-source components that ship with the operating system. In all, more than 25 bugs have been patched.

But the Internet flaw, which has to do with the Domain Name System (DNS), is the most widely publicized issue.

Apple, like many other operating-system vendors, was forced to patch its DNS software after security researcher Dan Kaminsky discovered a fundamental bug in the way this type of software is built.

On July 31, Apple had attempted to patch the flaw in Mac OS X, but security experts quickly discovered that while Apple's bug fix worked on the server side, it did not fix the issue on the client software.

With Monday's patch, Apple has fixed a flaw in the Mac OS X Libresolv DNS software that could have allowed attackers to trick victims into visiting malicious Web sites using what's known as a cache poisoning attack, said Andrew Storms, director of security operations with security vendor nCircle.

Libresolv is maintained by the Internet Systems Consortium (ISC). Although ISC had patched Libresolv by the time of Apple's last security update, the company did not include this bug fix in its July security update, Storms said.

After testing the 10.5.5 update Monday, he said that the Mac OS X client is now doing the required address port randomization that was added in ISC's bug fix. This is needed to make a cache poisoning attack much more difficult to pull off.

Also patched Monday were common Mac OS components such as Finder, Time Machine and the Mac OS kernel, as well as open-source components including Ruby ClamAV and OpenSSH.

At least nine of the patches fix flaws that could possibly be exploited by attackers to run unauthorized software on a victim's computer.

Join the newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags DNSMac OS X

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

Robert McMillan

IDG News Service
Show Comments

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Ben Ramsden

Sharp PN-40TC1 Huddle Board

Brainstorming, innovation, problem solving, and negotiation have all become much more productive and valuable if people can easily collaborate in real time with minimal friction.

Sarah Ieroianni

Brother QL-820NWB Professional Label Printer

The print quality also does not disappoint, it’s clear, bold, doesn’t smudge and the text is perfectly sized.

Ratchada Dunn

Sharp PN-40TC1 Huddle Board

The Huddle Board’s built in program; Sharp Touch Viewing software allows us to easily manipulate and edit our documents (jpegs and PDFs) all at the same time on the dashboard.

George Khoury

Sharp PN-40TC1 Huddle Board

The biggest perks for me would be that it comes with easy to use and comprehensive programs that make the collaboration process a whole lot more intuitive and organic

David Coyle

Brother PocketJet PJ-773 A4 Portable Thermal Printer

I rate the printer as a 5 out of 5 stars as it has been able to fit seamlessly into my busy and mobile lifestyle.

Kurt Hegetschweiler

Brother PocketJet PJ-773 A4 Portable Thermal Printer

It’s perfect for mobile workers. Just take it out — it’s small enough to sit anywhere — turn it on, load a sheet of paper, and start printing.

Featured Content

Product Launch Showcase

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?