Windows Security Update Targets Elevation of Privilege Attacks

Reports of hackers gaining superuser privileges raise concerns

Microsoft this week is continuing its ongoing investigation into what it calls "new public reports" of a vulnerability that could allow hackers to gain superuser privileges through LocalSystem in Windows XP, Windows Server 2003, Windows Vista and Windows Server 2008.

Redmond late last week issued a Security Advisory adding Windows XP Professional Service Pack 3 to the list of affected software. The advisory provides IT pros with some guidance and workarounds to help avoid a vulnerability that may allow elevation-of-privilege attacks.

The software giant said it is considering other actions, including the provision of a "security update" via its monthly Patch Tuesday security rollout.

This latest update involves a highly technical attack vector similar in scope to a patch released in last April's slate, where a local privilege-escalation vulnerability affected the Windows kernel due to improper validation of user-mode input. In the same manner, with this advisory, an attacker who has gained local access can change user parameters and exploit this issue to execute code with elevated permissions.

Microsoft said in its advisory that administrators that allow customized code to "run in an authenticated context, such as within Internet Information Services (IIS) and SQL Server," should take a look at the advisory.

Off-site server hosting providers running Windows programs may also face increased risk, Microsoft added.

Potential workarounds include log-in and process monitoring specifically in Internet Information Services. Administrators can do this by creating a Worker Process Identity through the ISS manager function in Windows. The same can be done in SQL Server with the database administrator keeping track of users and changes to fields and access privileges.

-- Jabulani Leffall

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