Exploits Available for Several Microsoft Vulnerabilities

Public exploits, which are often the precursors to widespread worm attacks, have appeared in the last week for several of the vulnerabilities that Microsoft unveiled and patched last week in its blockbuster security bulletin release.

On its monthly Patch Tuesday last week, Microsoft posted four security bulletins. Three of the bulletins contained fixes for critical flaws in Windows, the other was rated important. The most significant bulletin was MS04-011, which contained fixes for 14 separate vulnerabilities. Six of those vulnerabilities were rated as critical problems for one version of Windows or another.

"IT IS IMPERATIVE THAT THE PATCHES PROVIDED BY MICROSOFT IN ITS APRIL SECURITY RELEASE BE APPLIED TO SYSTEMS AS SOON AS POSSIBLE. It is our belief that the likelihood of a worm being released SOON that exploits one of the vulnerabilities addressed by these patches is VERY HIGH," Tom Liston, a handler on duty for the security-focused SANS Institute, wrote in a post a few days after Microsoft posted the bulletins. (Emphasis SANS).

In the days immediately following the bulletins, the SANS Institute posted notices of no fewer than four public exploits for vulnerabilities patched in bulletin MS04-011.

The first of the vulnerabilities to get its own public exploit was the SSL Vulnerability. The exploit has also been called the SSL Bomb, and it can result in a denial of service. Microsoft rated the SSL vulnerability important for Windows 2000, Windows XP and Windows Server 2003.

Exploits have also been created for two of the most dangerous flaws patched in MS04-011 -- the LSASS vulnerability and the ASN.1 "Double Free" vulnerability. Each can allow an attacker to remotely take control of a system. The LSASS vulnerability is critical for Windows 2000 and Windows XP, a low risk threat for Windows Server 2003 and doesn't affect Windows NT 4.0. The ASN.1 flaw is critical for all four of the Windows versions.

The other known exploit involves a threat rated important by Microsoft that only affects Windows 2000. Called the Utility Manager vulnerability, that flaw can allow privilege elevation.

The SANS Institute noted that a large exploit may be in the works. "We are hearing rumors of possible 'super' exploits that may target several of the vulnerabilities announced by Microsoft," the organization said. The group was investigating the rumors.

While the existence of working exploits for several of the flaws encourages users to immediately patch systems, many users have reported problems after installing the patches.

Visitors to have experienced slow performance, disabled disk drives, and broken applications, including Oracle 8.1.6. Many of the problems were fixed after uninstalling the patches. Microsoft has not released an updated version of any of the patches since the initial release on April 13.

About the Author

Scott Bekker is editor in chief of Redmond Channel Partner magazine.


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