Microsoft probes new Windows kernel bug

Investigates Israeli researcher's vulnerability disclosure

Microsoft on Friday said it is investigating an unpatched vulnerability in Windows after an Israeli researcher revealed a bug in the operating system's kernel driver.

According to Gil Dabah, a researcher from Tel Aviv who goes by the nickname "arkon," the Windows' kernel harbors a heap overflow vulnerability. Dabah also posted a short proof-of-concept to demonstrate the bug on RageStorm.com, a site he and two others run.

"Microsoft is investigating reports of a possible vulnerability in Windows Kernel," said Jerry Bryant on Friday. "Upon completion of the investigation, Microsoft will take appropriate actions to protect customers."

In an alert published Friday , Danish bug tracker Secunia pinpointed the bug in the "Win32k.sys" kernel-mode device driver, the kernel component of the Windows subsystem. Attackers could exploit the flaw using "GetClipboardData," an API (application programming interface) that retrieves data from the Window clipboard.

A successful exploit would allow hackers to execute their attack code in kernel mode, which would then let them infect the PC with malware or pillage any data on the machine.

The flaw exists in several versions of Windows, including XP SP3, Server 2003 R2, Vista, Windows 7 and Windows Server 2008 SP2, said Secunia, which rated the bug as "less critical," the firm's second-lowest threat ranking.

Microsoft has patched 13 Windows kernel vulnerabilities this year. In June, for example, MS10-032 patched three vulnerabilities in Win32k.sys; in April, it quashed eight bugs with MS10-021 ; and in February, MS10-015 fixed two flaws.

One researcher with experience digging up kernel bugs said the latest is business as usual. "I don't think there's been more than a few days this year that Microsoft [hasn't] been vulnerable to public kernel flaws," said Tavis Ormandy on Twitter . Ormandy reported three of this year's kernel vulnerabilities to Microsoft.

Most of those bugs were rated as "important," Microsoft's second-highest ranking, because they could not be exploited remotely, but required an attacker to have physical access to the PC and valid log-in credentials. It's likely that Dabah's find will as well.

Microsoft will issue 14 security updates , including 10 for Windows, on Tuesday. But unless the company found Dabah's flaw on its own, or the vulnerability was reported by another researcher earlier -- it's not unheard of for several researchers to stumble across the same bug -- a fix won't appear until September or later.

In the meantime, said Secunia, "Grant access [only] to trusted users."

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

Join the PC World newsletter!

Error: Please check your email address.

Tags MicrosoftsecuniasecurityWindowssoftwareoperating systems

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

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

Gregg Keizer

Computerworld (US)
Show Comments

Essentials

Lexar® JumpDrive® S57 USB 3.0 flash drive

Learn more >

Microsoft L5V-00027 Sculpt Ergonomic Keyboard Desktop

Learn more >

Mobile

Lexar® JumpDrive® S45 USB 3.0 flash drive 

Learn more >

Exec

HD Pan/Tilt Wi-Fi Camera with Night Vision NC450

Learn more >

Lexar® Professional 1800x microSDHC™/microSDXC™ UHS-II cards 

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

Learn more >

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

Budget

Back To Business Guide

Click for more ›

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?