Microsoft sounds bug alarm, confirms Windows-Word attacks

Promises patch to plug hole that's been exploited for weeks

Microsoft yesterday warned of a critical vulnerability that affects users of Word running on Windows 2000 , XP and Server 2003 SP1 -- several weeks after one security company first reported an exploit and a day after a second vendor confirmed ongoing attacks.

In an advisory posted Friday, Microsoft acknowledged "public reports of very limited, targeted attacks" that exploit a bug in the Microsoft Jet Database Engine, a Windows component that provides data access to applications including Microsoft Access and Visual Basic.

According to Symantec, however, the attacks Microsoft described used malicious Word 2000, 2002, 2003 and 2007 documents, which in turn call up the vulnerable Jet .dll.

"We believe that the issue being described [by Microsoft] is one described on March 20, 2008 by Elia Florio of Symantec Security Response," the security firm told customers of its DeepSight threat analysis network on Saturday. "He notes a recent discovery, by Panda Security, of a possible zero-day exploit observed in the wild."

Panda researcher Ismael Briones had blogged about the vulnerability nearly three weeks ago, but said Microsoft had dismissed his report of an in-the-wild exploit. "Microsoft replied that they would not fix these mdb vulnerabilities, as it seems they will not acknowledge vulnerabilities which are from .mdb files," Briones said in his March 3 post.

"You appear to be reporting an issue with a file type Microsoft considers to be unsafe. Many programs, such as Internet Explorer and Outlook, automatically block these files," Briones reported Microsoft as telling him in its e-mailed response.

Last week, however, Symantec researchers analyzed an exploit that circumvented the .mdb file format blocking in Outlook by simply renaming the file to a format the e-mail client accepted. "In fact, it is possible to call msjet40.dll directly from Word, without using Access at all," claimed Symantec's Florio in a Thursday post. "In this attack, the .doc file uses mail-merge functionalities to import an external data source file and so it effectively forces Jet to load the malicious Access sample."

Florio also noted that there are at least two unpatched bugs in Jet that have been exploited by hackers. One of those bugs was reported three years ago.

Microsoft said that users running Word on machines powered by Windows Vista and Windows Server 2003 SP2 are not at risk because those operating systems include a different version of Jet.

Although Microsoft downplayed the threat, spokesman Bill Sisk confirmed that a patch was on the way. "We currently have teams working to develop an update of appropriate quality for release in our regularly scheduled bulletin process or as an out-of-band update, depending on customer impact," he said in a post to the Microsoft Security Response Center's blog.

Until a fix is available, Microsoft said users and IT administrators could disable Jet or block .mdb files at the gateway.

The next scheduled Microsoft patch day is Tuesday, April 8.

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

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

Lexar® JumpDrive® C20c USB Type-C flash drive 

Learn more >

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

Learn more >

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

Learn more >

Audio-Technica ATH-ANC70 Noise Cancelling Headphones

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?