ZDI-09-083: Microsoft Excel Shared Feature Header Pointer Offset Memory Corruption Vulnerability
http://www.zerodayinitiative.com/advisories/ZDI-09-083
November 10, 2009

-- CVE ID:
CVE-2009-3129

-- Affected Vendors:
Microsoft

-- Affected Products:
Microsoft Office Excel

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 9231. 
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-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Microsoft Office Excel. User interaction is
required to exploit this vulnerability in that the target must open a
malicious spreadsheet.

The specific flaw exists in the handling of Shared Feature Header
(0x867) tags in an Excel BIFF file format. When processing the cbHdrData
size element of the FEATHEADER it is possible to directly control the
distance of a calculated pointer. This condition can be leveraged
successfully to execute arbitrary code under the context of the
currently logged in user.

-- Vendor Response:
Microsoft has issued an update to correct this vulnerability. More
details can be found at:

http://www.microsoft.com/technet/security/bulletin/MS09-067.mspx

-- Disclosure Timeline:
2009-10-20 - Vulnerability reported to vendor
2009-11-10 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * Anonymous

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