TippingPoint Zero Day Initiative
 

Microsoft Excel Shared Feature Header Pointer Offset Memory Corruption Vulnerability

ZDI-09-083: November 10th, 2009

CVE ID

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 9231. For further product information on the TippingPoint IPS:

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:

Disclosure Timeline

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

Credit

This vulnerability was discovered by:
    Anonymous