Microsoft Windows Help and Support Center URL Processing Vulnerability

SA40076

CVE-2010-1885, CVE-2010-2265

10 Jun 2010

13 Jul 2010

Highly Critical

Vendor Patch

From remote

System access

This covers vulnerabilities where malicious people are able to gain system access and execute arbitrary code with the privileges of a local user.

Tavis Ormandy has discovered a vulnerability in Microsoft Windows, which can be exploited by malicious people to compromise a user's system.

The vulnerability is caused due to an error when processing escaped URLs through Microsoft Windows Help and Support Center (helpctr.exe). This can be exploited to bypass restrictions normally imposed by the "-FromHCP" command-line argument and pass arbitrary parameters to local help documents.

Successful exploitation allows execution of arbitrary commands through the use of an additional input sanitation error in the sysinfomain.htm help document when opening a specially crafted "hcp://" URL.

The vulnerability is confirmed in Windows XP SP3 with Windows Media Player 9 and Internet Explorer 8. Windows Server 2003 is also reportedly affected.

Apply patches.

Windows XP SP2/SP3:
http://www.microsoft.com/downloads/details.aspx?familyid=7C2122BB-0ECF-4467-A3BA-6FB862F603C5

Windows XP Professional x64 Edition SP2:
http://www.microsoft.com/downloads/details.aspx?familyid=9232A336-9DED-4820-BAC4-2D68877EE76C

Windows Server 2003 SP2:
http://www.microsoft.com/downloads/details.aspx?familyid=CD4363B2-D7A7-4FFF-8BCD-6FD02BD1AC07

Windows Server 2003 x64 Edition SP2:
http://www.microsoft.com/downloads/details.aspx?familyid=A6BAFD3B-C921-466D-BEE0-59A3FE126712

Windows Server 2003 with SP2 for Itanium-based Systems:
http://www.microsoft.com/downloads/details.aspx?familyid=B61CC2D5-8432-4681-AA2C-A8807EC1FCF4

Tavis Ormandy

MS10-042 (KB2229593):
http://www.microsoft.com/technet/security/bulletin/ms10-042.mspx

Tavis Ormandy:
http://archives.neohapsis.com/archives/fulldisclosure/2010-06/0197.html