Microsoft patches Vista bug that snuck through beta

Security bulletin patches eight Microsoft vulnerabilities

Microsoft Tuesday unveiled the second stage of its April security updates by releasing five security bulletins that patched eight vulnerabilities -- including one that was missed during the company's Windows Vista beta testing and ended up in the final version of the new operating system.

Of the four updates that addressed bugs in Windows, the MS07-021 update was clearly the one to patch pronto, said researchers. "This is my first [to patch] choice," said Amol Sarwate, manager of Qualys's research lab.

"It affects everyone," agreed Minoo Hamilton, senior security researcher with patch management vendor nCircle Network Security.

The update, which fixes three different bugs, includes one marked critical that affects all supported editions of Windows, from 2000 through XP and Server 2003 to Vista. The vulnerability in the error message processing of the Windows Client/Server Run-time Subsystem (CSRSS) can be exploited remotely, said Microsoft, and could result in a complete compromise of the PC.

The most likely way to deliver an attack: dupe users into visiting a malicious Web site.

Ironically, this MsgBox flaw was acknowledged by Microsoft more than three months ago, and was reported to the company's security team about the same time as the animated cursor (ANI) bug patched by an emergency fix last week.

"Number one, it affects earlier operating systems as well as Vista, so it's similar to the ANI vulnerability in that it's likely Microsoft reused [older] code in Vista," said Sarwate. "Two, it's a zero-day; it was out there [publicly] before today. Three, it has a Web-based attack scenario. And fourth, last but not least, it affects both clients and servers, and is a core component of the operating system."

Hamilton concurred, especially on the reused code and the similarity with ANI. "It confirms a lot that we discussed about the ANI bug and the type of vulnerabilities Vista will likely have," he said. "The file handing- and process- and local privilege escalation-type vulnerabilities will be what attackers focus on with Vista."

But Hamilton also cast back to 2006, when Vista was still in beta testing. "This vulnerability was in the betas, so it escaped from the beta all the way to now."

The federal government's National Vulnerability Database confirmed Hamilton's charge. In a vulnerability summary first posted Dec. 21, 2006, a day before Microsoft acknowledged the bug, it listed Vista Beta 1 and Vista Beta 2 as affected.

Of the remaining four updates, Sarwate and Hamilton split on pegging the next-most-dangerous bugs. Sarwate called out MS07-018 and MS07-019, both ranked critical by Microsoft; Hamilton, meanwhile, picked MS07-020 as the second most-important update he recommended users deploy.

"MS07-019 is potentially wormable," said Sarwate, because a hacker can actively send packets to two listening ports and there's no user interaction required." Hamilton's choice, MS07-020, is rated critical on both Windows 2000 and Windows XP SP2, which account for the bulk of Windows clients.

"The one bright spot," said Hamilton, "is that MS07-020 shows us a trend. Take a look at the 'Mitigating factors' in the bulletin. It shows a progressive locking down of the operating system from Windows XP SP2 to Windows Server 2003 to Windows Vista.

"But then you turn around, and there's MS07-021, and you see Vista breaking out of those protections."

Join the PC World newsletter!

Error: Please check your email address.

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
Show Comments

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?