TippingPoint Zero Day Initiative
 

Microsoft Excel BIFF File Format Cell Record Parsing Memory Corruption Vulnerability

ZDI-08-008: March 11th, 2008

CVE ID

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 5338. 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 parsing 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 under the logged in users credentials.

Vendor Response

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

Disclosure Timeline

    2007-05-22 - Vulnerability reported to vendor
    2008-03-11 - Coordinated public release of advisory

Credit

This vulnerability was discovered by:
    Arnaud Dovi - ad@heapoverflow.com