Remember last May (2005) when security experts warned of a security hole in Internet Explorer? ("Which one?" you're probably asking.) Last May's vulnerability involved the manner by which Internet Explorer processes the "Window()" function in JavaScript. Microsoft and other security experts pooh-poohed the vulnerability, believing that it wasn't really serious.

However, in December 2005, a London-based security firm called Computer Terrorism Ltd. published proof-of-concept code showing how hackers can exploit this very problem and take over a user's Windows system.

In order to take advantage of the flaw, an attacker first tricks the user into clicking on a Web link that directs the browser to a site containing the malicious code. Once this malicious code is launched by the JavaScript, it can set up a chain of events that can let a hacker gain control of the user's system. Computer Terrorism Ltd.'s code demonstrates how.

Windows 98, 2000, XP Vulnerable

Security experts who examined this problem last May recommended that users running Windows 98, Windows 2000, and Windows XP turn off JavaScript until Microsoft got around to fixing the bug in IE. This can be done by disabling "active scripting" in the Internet Options menu.

But unfortunately, JavaScript is one of the most commonly used scripting languages on Web sites today, so disabling JavaScript in IE created serious problems for lots of users who run IE on the older versions of the Windows operating systems. Most of these users did not disable JavaScript, simply because suddenly most of the world's Web sites no longer functioned properly.

A so-called "temporary fix" that some security experts then recommended suggested that users deploy alternative browsers, such as Firefox or Opera, which do not have the JavaScript bug. As a result, the number of users turning to Firefox suddenly began to rise, as IT departments began rolling out the new browser applications.

Meanwhile, Microsoft examined the problem and then reported that customers running Windows Server 2003 and Windows Server 2003 Service Pack 1 in their default configurations, with the Enhanced Security Configuration turned "on," would not be affected by the IE JavaScript bug. And because Microsoft doesn't really like to support JavaScript anyway, the company then ignored the IE JavaScript problem for users of the older versions of Windows.

So that was the state of the JavaScript problem up until last month, when Computer Terrorism Ltd. published proof-of-concept code. The bug is real, according to Computer Terrorism Ltd., and it will now be only a matter of time before hackers take control and turn hundreds of thousands of Windows machines into zombies.

Of course, Microsoft is now miffed at Computer Terrorism Ltd. for reminding everybody that the bug in IE was never fixed, but security experts are wondering what's taken Microsoft so long to get around to plugging the security hole to begin with.

Another IE Vulnerability

Meanwhile, hackers posted two samples of code that could be used to attack a Windows machine that has not been updated with the most recent Microsoft security patches.

The French Security Incident Response Team (FrSIRT) Web site posted these samples of a maliciously encoded image file that could be used by attackers to grind a Windows PC to a halt! That's right! A Windows machine can be crashed by simply viewing an image file! These published examples exploit the critical vulnerability in the way Windows processes files saved in the Windows Metafile (.wmf and .emf extensions) graphics format.

When IE views specially crafted files that contain the malicious code, the PC's CPU utilization will climb to 100%, causing the PC to crash. The Windows Metafile problems affect virtually all supported versions of Windows, according to Microsoft's Web site. This kind of vulnerability could be key to creating a massive denial-of-service (DoS) attack against anyone with connectivity to the Internet.

Fixing the Bugs

But wait! Microsoft says it fixed this Metafile bug in its MS05-053 Security Update, which was released just last November 8! "Everybody should have these now," Microsoft says. "All they have to do is enable the Windows Update feature or go to the Microsoft Update Web site."

However, this creates a second conundrum for users of Windows 98, XP, and 2000....

Damned if You Do! Damned if You Don't!

If a user is running an alternative browser, such as Firefox or Opera—in response to the bug Microsoft failed to fix last May—and he attempts to obtain the Microsoft updates from http://update.microsoft.com Web site, he will receive the following message: "Thank you for your interest in obtaining updates from our site. To use this site, you must be running Microsoft Internet Explorer 5 or later."

In other words, by ignoring the importance of the critical JavaScript bug in IE that was reported last May, Microsoft has forced some users to either disable JavaScript or rely upon alternative browsers that it will not support when delivering its patches to other Microsoft products.

(As of this writing, Microsoft says that it will release the bug fix as part of its Windows Update function on January 10.)

Still More Bugs!

Also in December, hackers released even more code that took advantage of yet another Windows security hole that was purportedly patched in October. That software exploited a flaw in the Microsoft Distributed Transaction Coordinator (MSDTC), a component of the operating system that is commonly used by database software to help manage transactions.

The MSDTC attack software can be used to knock Windows systems out of operation. The code that took advantage of this flaw has been in circulation since mid-October, but it had not been posted on a public Web site before December. Of course, to obtain a patch for this vulnerability, you have to go to the http://update.microsoft.com site, too. And what do you need to obtain it? Internet Explorer, of course!

What's a Poor User to Do?

Clearly then, Microsoft's strategies to provide remedies to IE security holes need some tweaking.

Users should not normally be required to disable major functionality of a product—such as JavaScript in IE—in order to remedy a known vulnerability. Or, if that is the only means of providing the remedy until a fix is provided, Microsoft should make it a priority to supply a patch as quickly as possible. Such should have been the case with the IE JavaScript vulnerability, since so many Web sites utilize JavaScript today.

Instead, Microsoft forced users to choose browsers from competitors, which then limited Microsoft's ability to provide further patches for all of its Windows products through the IE delivery mechanism.

Remedies for the Windows/IE Support Conundrum

Microsoft could do a lot of tactical things to prevent this kind of support bottleneck in the future. For instance, it could develop a patch-delivery system that doesn't rely upon Internet Explorer, an application that has been proven over and over to be one of the main sources of security vulnerabilities itself. It has now done this for major updates to the operating system, but it should also make this functionality available for non-IE browsers.

Or, separately, it could donate the source of IE to the open source community and let the community determine how best to deploy future security fixes to the product. This would enable Microsoft to focus on more critical security issues in its operating systems' products. And, by doing so, IE could then be allowed to become a true international standard. Since Microsoft doesn't directly benefit from sales of IE, one might think this was the most logical thing to do.

However, Microsoft continues to use IE as a wedge for implementing its other technologies, such as Active-X and .NET, technologies that are critical to its overall plan for continued dominance in the PC operating system environment.

At the very least, Microsoft should establish a "zero tolerance" security policy for IE, in which any reported vulnerability receives the highest priority, regardless of the support profiles of the underlying operating systems that it is running upon. This would mean that instead of pooh-poohing marginal vulnerabilities (as the latest holes were once deemed), an all-out effort would be made to patch them as quickly as possible.

Unfortunately, we've all grown accustomed to security breaches with Microsoft products, so our standards for this flawed product have eroded over the years. Likewise, when Microsoft assures us now that it takes these issues seriously, we continue to roll our eyes and silently bite our lips, hoping that Microsoft's sloppiness doesn't prove to be the undoing of our organizations' security.

Thomas M. Stockwell is Editor in Chief of MC Press Online, LP.