Worst Windows flaws of the past decade

The exploits and oversights that left Redmond with egg on its face

Fastest infection. Ever.

Bug identifier: MS02-039

Description: Buffer overruns in SQL Server 2000 Resolution Service could enable remote code execution

Alias: The SQL Slammer bug

Date published: July 24, 2002

While technically not an OS bug, the SQL Slammer bug deserves honorary mention due to the sheer velocity with which vulnerable systems were infected. The bug targeted Microsoft's database server. Vulnerable computers were subject to buffer overflows that, if properly crafted, could place commands into memory to cause the targeted system to execute those commands with the permissions of the database service.

Patching was complicated by the fact that admins needed to run an earlier patch before they could run the MS02-039 fix. The bug affected primarily corporate server systems, but also affected home users who had MSDE (Microsoft SQL Server Desktop Engine) installed. That made a number of home users, some of whom didn't even know they had MSDE on their machines, unwitting participants in the carnage to come.

Because the Slammer worm primarily targeted servers running databases, it didn't infect millions of machines. It did, however, spread rapidly -- so rapidly, in fact, that it had infected roughly 9 out of 10 vulnerable machines within 10 minutes of being released on January 25, 2003. The entire worm was only 376 bytes, and fit into a single packet of data.

The MS02-039 bug was "one of the biggest oversights of all time," says Steve Manzuik, senior manager of security research at Juniper Networks, "not because it was an easy or obvious bug to find -- it wasn't."

"At the time of the patch, no one realized that every vulnerable SQL installation was also listening on a UDP (User Datagram Protocol) port that they could be exploited over," Manzuik explains. "Many administrators simply locked down access to the SQL TCP ports while forgetting about UDP."

A postmortem by the Cooperative Association for Internet Data Analysis revealed that the worm was a model of efficiency, doubling the number of infected systems every 8.5 seconds, and flooding the Internet with so many infection attempts that routers shut down. When restarted, so many routers attempted to update their routing tables simultaneously that normal Internet traffic simply couldn't get through the gridlock.

Upshot: SQL Slammer demonstrated the power of a vulnerability that could fit within a single data packet, and brought home the lesson that a single application weakness could cause the entire Internet to grind to a standstill. And it's still out there, drifting around on a few old systems, looking for new hosts to infect.

Join the PC World newsletter!

Error: Please check your email address.

Tags Windows Vistawindows xpWindows 2000windows 98

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.

Andrew Brandt

Show Comments

Most Popular Reviews

Latest News Articles


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?