Researcher reveals Safari zero-day bug

Drive-by exploit confirmed in Windows version of Apple's browser

Apple's Safari browser contains a critical, unpatched bug that attackers can use to infect Windows PCs with malicious code, researchers at US-CERT and other security firms said today.

Hackers could compromise PCs with simple "drive-by" attack tactics, researchers added.

The vulnerability, first reported by Danish vulnerability tracker Secunia and confirmed by the United States Computer Emergency Readiness Team (US-CERT), was disclosed by Polish researcher Krystian Kloskowski on Friday. The bug is caused by an error in the handling of the browser's parent windows.

"This can be exploited to execute arbitrary code when a user visits a specially-crafted Web page and closes opened pop-up windows," said Secunia's alert .

The vulnerability can also be exploited by attackers who dupe users into opening rigged HTML-based e-mail within Safari, added US-CERT in its advisory . That scenario likely would involve tricking users into opening malicious messages in a Web mail service, such as Gmail or Windows Live Hotmail.

Both Secunia and US-CERT confirmed today that the proof-of-concept attack code published by Kloskowski successfully compromises the Windows version of Safari 4.0.5, the most up-to-date edition. Secunia rated the vulnerability as "highly critical," the second-most-dangerous ranking in its five-step threat scoring system.

It's not known whether the vulnerability also exists in the much more widely used Mac OS X version of Apple's software. "Other versions may also be affected," cautioned US-CERT.

Charlie Miller, the noted vulnerability researcher who won $10,000 by hacking a Mac in March at the Pwn2Own contest, was out of his office and not able to verify that the bug also exists in Safari on Mac OS X.

US-CERT urged users of the Windows version of Safari to disable JavaScript as a temporary defense.

Apple last patched Safari in mid-March when it fixed 16 flaws, including six that applied only to the Windows version of the browser. It's not unusual for Apple to patch Windows-only vulnerabilities when it updates Safari.

Apple patched Miller's $10,000 vulnerability in mid-April by plugging a hole in ATS (Apple Type Services), a font renderer included with Mac OS X. Miller accessed the ATS bug via Safari during Pwn2Own.

Gregg Keizer covers Microsoft, security issues, Apple, Web browsers and general technology breaking news for Computerworld . Follow Gregg on Twitter at @gkeizer or subscribe to Gregg's RSS feed . His e-mail address is gkeizer@ix.netcom.com .

Read more about security in Computerworld's Security Knowledge Center.

Join the newsletter!

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

Tags securityApplejavascriptMicrosoft Windowssafaribug

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

Gregg Keizer

Computerworld (US)
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

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.

Walid Mikhael

Brother QL-820NWB Professional Label Printer

It’s easy to set up, it’s compact and quiet when printing and to top if off, the print quality is excellent. This is hands down the best printer I’ve used for printing labels.

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.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?