With Non-Critical Bugs Like These, Who Needs the Real Thing?

By Larry Seltzer  |  Posted 2004-12-16 Print this article Print

Opinion: Microsoft's classification of the WINS bug as "Important" badly understates its importance. This is a bad one.

It sure caught me by surprise. After Microsofts early warning indicated that the five vulnerability disclosures this week would be no more than "Important"—as opposed to "Critical"—I figured no biggie, I went out for the day. Well, if this is what Microsoft doesnt call "Critical" then their standards have changed. MS04-045—known far and wide as the WINS bug—is the worst example of this.

Microsoft explains their reasoning for the "Important" classification for this bug: "... because it was not an Internet-facing technology and because the service is not installed by default on Windows systems."

This is dissatisfying and possibly disingenuous. Microsoft makes no bones about recommending that all organizations that use Exchange use WINS (along with DNS) for their name resolution. Many important functions of Exchange Server still rely on it. And its not the only application that requires WINS.

Its true, as Microsoft says, that WINS isnt, or at least neednt be, an Internet-facing technology. If your firewalls havent been blocking port 42 by now, they should be. But thats only part of the problem. Many worms, once they penetrate a system, use other techniques to spread. For example, if someone were to infect their PC with the Maslan worm, it would use that computer to attack others on the local network with the LSASS and RPC/DCOM vulnerabilities.

For insights on security coverage around the Web, check out eWEEK.com Security Center Editor Larry Seltzers Weblog. Its not hard to imagine a future version of Maslan adding the WINS exploit to its quiver. At that point all the unpatched Exchange servers on the internal network are exploitable. So much for the exploit not being "wormable."

I should say that its good to see Microsoft patch an important NT4 bug, and the WINS bug isnt the only one. When the WINS bug went public (thanks to the Secunia and their usual reckless judgment) I figured that Microsoft wouldnt be able to fix it before the end of the year. After that point they changed their policies for Windows NT 4 support, but exactly what they extended beyond the end of the year is still ambiguous from their statements. Microsoft said that they also had received responsible, confidential disclosure of the bug from "Kostya Kortchinsky from CERT RENATER" and credited him in the bulletin. I knew Microsoft wouldnt be able to put a finished patch together in the amount of time Secunia gave them.

Another patch, MS04-042, was NT4-only. It allowed a DHCP client to take control of an NT4 DHCP server. Ill just say ditto to my previous lecture on exploits from the internal network.

There were also code execution bugs in applications Hyperterminal and Wordpad. I have to agree that these would be tough to exploit and certainly arent wormable.

I have to think that Microsoft knows better than the excuses they put up as mitigating circumstances, especially for the WINS bug. We can only hope that no clever exploit comes out, at least anytime soon. It is possible to protect yourself, even without the patch, but the first thing you need to do is to understand how serious the problem is, and Microsofts explanations are no help in that regard.

Security Center Editor Larry Seltzer has worked in and written about the computer industry since 1983. Check out eWEEK.coms for the latest security news, reviews and analysis. More from Larry Seltzer
Larry Seltzer has been writing software for and English about computers ever since—,much to his own amazement—,he graduated from the University of Pennsylvania in 1983.

He was one of the authors of NPL and NPL-R, fourth-generation languages for microcomputers by the now-defunct DeskTop Software Corporation. (Larry is sad to find absolutely no hits on any of these +products on Google.) His work at Desktop Software included programming the UCSD p-System, a virtual machine-based operating system with portable binaries that pre-dated Java by more than 10 years.

For several years, he wrote corporate software for Mathematica Policy Research (they're still in business!) and Chase Econometrics (not so lucky) before being forcibly thrown into the consulting market. He bummed around the Philadelphia consulting and contract-programming scenes for a year or two before taking a job at NSTL (National Software Testing Labs) developing product tests and managing contract testing for the computer industry, governments and publication.

In 1991 Larry moved to Massachusetts to become Technical Director of PC Week Labs (now eWeek Labs). He moved within Ziff Davis to New York in 1994 to run testing at Windows Sources. In 1995, he became Technical Director for Internet product testing at PC Magazine and stayed there till 1998.

Since then, he has been writing for numerous other publications, including Fortune Small Business, Windows 2000 Magazine (now Windows and .NET Magazine), ZDNet and Sam Whitmore's Media Survey.

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