Microsoft Windows MHTML XSS vulnerability

A vulnerability has been reported in Microsoft Windows, which can be exploited by malicious people to conduct cross-site scripting (XSS) attacks, according to Secunia.

The vulnerability is caused due to an error in the way the MHTML (MIME Encapsulation of Aggregate HTML) protocol handler interprets MIME-formatted requests for content blocks within a document.

This can e.g. be exploited via Internet Explorer to execute arbitrary HTML and script code in a user’s browser session in context of a web site.

Microsoft is aware of published information and proof-of-concept code that attempts to exploit this vulnerability. At this time, Microsoft has not seen any indications of active exploitation of the vulnerability.

Solution: Enable MHTML protocol lockdown (either manually or using the available automated “Microsoft Fix it” solution).

Affected Software:

  • Windows XP Service Pack 3
  • Windows XP Professional x64 Edition Service Pack 2
  • Windows Server 2003 Service Pack 2
  • Windows Server 2003 x64 Edition Service Pack 2
  • Windows Server 2003 with SP2 for Itanium-based Systems
  • Windows Vista Service Pack 1 and Windows Vista Service Pack 2
  • Windows Vista x64 Edition Service Pack 1 and Windows Vista x64 Edition Service Pack 2
  • Windows Server 2008 for 32-bit Systems and Windows Server 2008 for 32-bit Systems Service Pack 2 (Server Core installation not affected)
  • Windows Server 2008 for x64-based Systems and Windows Server 2008 for x64-based Systems Service Pack 2 (Server Core installation not affected)
  • Windows Server 2008 for Itanium-based Systems and Windows Server 2008 for Itanium-based Systems Service Pack 2
  • Windows 7 for 32-bit Systems
  • Windows 7 for x64-based Systems
  • Windows Server 2008 R2 for x64-based Systems (Server Core installation not affected)
  • Windows Server 2008 R2 for Itanium-based Systems.

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