TippingPoint Zero Day Initiative
 

Microsoft Office Excel File Rebuilding Code Execution Vulnerability

ZDI-06-022: July 11th, 2006

CVE ID

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 4330. 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. Exploitation requires that the attacker coerce the target into opening a malicious .XLS file.

The specific flaw exists within the rebuilding of malformed cell comments. When Excel encounters a malformed record it attempts to rebuild the broken meta-data. A flaw in this rebuilding process allows the user to specify critical data offsets eventually leading to code execution with the credentials of the current user.

Vendor Response

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

Disclosure Timeline

    2006-06-15 - Vulnerability reported to vendor
    2006-07-11 - Coordinated public release of advisory

Credit

This vulnerability was discovered by:
    Arnaud Dovi 'class101' http://heapoverflow.com