TippingPoint Zero Day Initiative

Microsoft Office Word PAPX Section Remote Code Execution Vulnerability

ZDI-12-201: December 21st, 2012


CVSS Score

Affected Vendors

Affected Products

TippingPoint™ IPS Customer Protection

TippingPoint IPS customers are protected against this vulnerability by Digital Vaccine protection filter ID 11933. 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 Word. User interaction is required to exploit this vulnerability in that the target must visit a malicious page or open a malicious file.

The specific flaw exists within how the application parses a PAPX FKP sections. When parsing a PAPX FKP section, the application will store a calculation. However, when repairing a damaged document, the application will explicitly trust this calculation in a loop that is used to index into an array of objects. This will allow for an out-of-bounds access of an object which can lead to code execution under the context of the application.

Vendor Response

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

Disclosure Timeline

    2011-05-25 - Vulnerability reported to vendor
    2012-12-21 - Coordinated public release of advisory


This vulnerability was discovered by: