Open-source flaw threatens Microsoft

NEWS

A security flaw in open-source software used by Linux and Unix systems for compression may affect some Microsoft products that also use the code. As reported earlier this week by ZDNet UK, a flaw in the zlib software-compression library could leave much of the systems based on the open-source operating system Linux open to attack. On Thursday, researchers reported that at least nine of Microsoft's major applications -- including Microsoft Office, Internet Explorer, DirectX, Messenger and Front Page -- appear to incorporate borrowed code from the compression library and could be vulnerable to a similar attack. Microsoft representatives said that the software giant's security response team is investigating the zlib flaw and that some Microsoft applications use code from that compression library. However, the team hasn't yet determined which applications use the library and whether those applications are vulnerable. "It's not a foregone conclusion that the applications are affected," a company representative said. The zlib library has been a fundamental open-source software component for almost a decade and can be found in almost every Linux and Unix system. That means the so-called "double free" flaw in the library may leave a hefty portion of Linux and Unix systems open to attack. Because it adopted some of the code, Microsoft apparently has made itself vulnerable to the flaw as well. Members of the open-source compression project, Gzip, have posted a list of nearly 600 applications that a detection program has flagged as using the zlib code. Nine Microsoft applications are included in the list: Microsoft DirectX 8, FrontPage, the next-generation Graphics Device Interface, InstallShield, Internet Explorer, Office, NetShow, Visual Studio and Messenger. The next-generation Graphics Device Interface is part of Windows XP, meaning that the operating system itself could be at risk. The detection program uses three signature strings of code -- and for in-depth searches, several more -- found in the zlib software to determine if functions from the library are present in a specific program. For example, Microsoft's Direct X contains 18 error messages that are identical to those in zlib, said Jean-loup Gailly, the chief software architect for computer image recognition company Vision IQ and the co-creator of the zlib library. "Microsoft is affected but may not be vulnerable," Gailly said. Depending on how the software giant wrote the other software libraries upon which zlib depends will determine whether the company's code is at risk, he added. Companies that use code from the open-source community need to always vet the code for such insecurities, IDC analyst Dan Kusnetzky said. "Some of the open-source products are quite well-tested and don't have very many vulnerabilities," he said. "Others aren't so well-tested, and so may have vulnerabilities that will embarrass the companies later." The zlib library's double-free flaw shows that even well-tested software can still fall prey to some of the more esoteric security problems, he added. The license under which the zlib library is published on the Internet allows any company to use the code in any way it likes. Unlike the GNU General Public License, the library doesn't require that a company release its own source code in return. Yet, the incident seemingly proves that Microsoft, despite dismissing open-source code publicly, has used software from others to create their own products. Borrowing from the open-source world
This isn't the first time that Microsoft has included code from the open-source arena. Some programmers have said that a technology, called the GS flag, which the software giant added to its newest compiler to prevent a common programming error, actually uses code from the open-source StackGuard project. "It is debatable that Microsoft copied the StackGuard functionality," Crispin Cowan, chief scientist at server software firm Wirex Communications and the creator of StackGuard, wrote in a February email to CNET News.com. "It is not debatable that the GS functionality is identical to... StackGuard." Evidence uncovered last summer points to the Windows operating system borrowing some networking utilities and possibly parts of the TCP/IP stack, the core software that allows networking and Internet connectivity, from the open-source Unix variant FreeBSD. Theo de Raadt, a founder and project leader for another open-source Unix variant, OpenBSD, stressed that no conclusive proof exists, however. "I have asked repeatedly and never gotten proof," he said. Microsoft has never denied that it would use open-source software, just that its programmers are prohibited from using code based on the GNU General Public License, which could force the company to publish its own source code. "The issue at hand is choice; companies and individuals should be able to choose either model, and we support this right," Craig Mundie, senior vice president of Microsoft, said last May. "(There) is a real problem in the licensing model that many open-source software products employ: the General Public License." The zlib compression library doesn't use the GPL, however. For the library, the only license requirement is that a copyright notice be included in the program source-code, if released. Microsoft, which rarely releases source code, didn't need to include the string in the company's programs, but zlib creator Gailly wishes the giant gave credit. "It bothers me that they removed the zlib copyright string from some binary versions," he said. In the future, he added, new versions of the library may include such a requirement.

For all security-related news, including updates on the latest viruses, hacking exploits and patches, check out ZDNet UK's Viruses and Hacking News Section. Have your say instantly, and see what others have said. Go to the Security forum. Let the editors know what you think in the Mailroom.

Post your comment

In order to post a comment you need to be registered and logged in.

You can also log in with Facebook. Log in or create your ZDNet UK account below

By signing up for this service, you indicate that you agree to our Terms and Conditions and have read and understood our Privacy Policy. Questions about membership? Find the answers in the Community FAQ

ZDNet UK Live

For Gnome 2 die-hards, it is possible to add icons to the bottom panel (or top top panel, if you prefer) which provide the exact Gnome 2...

34 minutes ago by Moley on A tale of two distros: Ubuntu and Linux Mint

Your comments would seem pretty naive and immature. Your 'solution' appears to be, "gee, let's all just give in to the hackers and give them...

46 minutes ago by ramwellian on Cloud computing security: no more oxymoron?

"Interesting thought ... If you installed Win7 as a dual boot on a machine that previously only had Linux, and it wrecked your Linux installation,...

1 hour ago by BugStalker on Windows 7 Declares War on GRUB

This is an excellent summary of Ubuntu and Mint and the interface differences between them. Most such articles take a very partisan position for...

1 hour ago by whs001 on A tale of two distros: Ubuntu and Linux Mint

@ewallace. Not so clear. Anyone can obtain the text, for example from here http://www.ustr.gov/webfm_send/2379. I support ACTA so long as it and...

1 hour ago by Moley on ACTA: Facts, misconceptions and questions

I think WinRT is fantastic. I just wish it was an option for people that didn't want to go through Microsoft's App Store with its attendant...

5 hours ago by 45283 on Why Windows 8 needs architectural hygiene for WOA

Nine people? £30m? Who's back pocket is that lot going in? And IF they say it is for new buildings, what about all the ones the government has...

6 hours ago by Burn-IT on Police set to launch three £30m e-crime hubs

Just to be clear, nobody knows what is in the text of ACTA, here is a photograph of the text of ACTA http://twitpic.com/8h9iju as submitted to the...

6 hours ago by ewallace on ACTA: Facts, misconceptions and questions

Unfortunately main issue is that ASUS is refusing to accept that they make some mistake on this version of asus Transformer prime. 1 - GPS sensor...

7 hours ago by fgvrg56 on Asus Eee Pad Transformer Prime Wi-Fi & GPS problems?

@Marcus A fair question. Just talked with Archos which said it was working on an announcement for next week....

8 hours ago by Ben Woods on Archos confirms G9 Ice Cream Sandwich update schedule

Any update on this, considering the claimed "first week of February"?

9 hours ago by Marcus Karlsson via Facebook on Archos confirms G9 Ice Cream Sandwich update schedule

Bill Goodrich : Just as al_langevin pointed out, with Windows Server 2008 there is no Services for Macintosh anymore. It's gone, not available....

17 hours ago by apexwm on Windows Server 2008 drops the ball for Mac compatibility

Replying to an old topic that I'm currently facing with my CEO (who is on a Mac). Our servers are primarily Windows Servers, office is about...

24 hours ago by txtrainguy on Windows Server 2008 drops the ball for Mac compatibility

Sure, that makes perfect sense. Pay wrong-doers money and thank them for breaching your security and pointing out your flaws, that would surely...

1 day ago by k0tcs3 on US indicts Romanian over NASA climate change hack

I think he's referring specifically to Android apps, as Apple do regulate their App Store, but Google seem to let any old crap onto the Android store!

1 day ago by Random_Error on RIM: BlackBerry will keep 'garbage' apps out of store