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!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags Mac OS XDNS

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

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Laura Johnston

MSI GS65 Stealth Thin

If you can afford the price tag, it is well worth the money. It out performs any other laptop I have tried for gaming, and the transportable design and incredible display also make it ideal for work.

Andrew Teoh

Brother MFC-L9570CDW Multifunction Printer

Touch screen visibility and operation was great and easy to navigate. Each menu and sub-menu was in an understandable order and category

Louise Coady

Brother MFC-L9570CDW Multifunction Printer

The printer was convenient, produced clear and vibrant images and was very easy to use

Edwina Hargreaves

WD My Cloud Home

I would recommend this device for families and small businesses who want one safe place to store all their important digital content and a way to easily share it with friends, family, business partners, or customers.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?