VUPEN Security Research - Microsoft Office Excel Extra PtgExtraArray Parsing 
Vulnerability (CVE-2010-3239)

http://www.vupen.com/english/research.php


I. BACKGROUND
---------------------

Microsoft Office Excel is a powerful tool you can use to create and
format spreadsheets, and analyze and share information to make more
informed decisions. With the Microsoft Office Fluent user interface,
rich data visualization, and PivotTable views, professional-looking
charts are easier to create and use.


II. DESCRIPTION
---------------------

VUPEN Vulnerability Research Team discovered a critical vulnerability
in Microsoft Office Excel.

The vulnerability is caused by a memory corruption error when processing
PtgExtraArray structures in an Excel file, which could be exploited
by remote attackers to execute arbitrary code by tricking a user into
opening a specially crafted Excel document.


III. AFFECTED PRODUCTS
---------------------------

Microsoft Office XP Service Pack 3


IV. Binary Analysis & Exploits/PoCs
---------------------------------------

In-depth binary analysis of the vulnerabilities fixed by Microsoft
in October 2010 and code execution exploits or PoCs are available
through the VUPEN Binary Analysis & Exploits Service :

http://www.vupen.com/english/services/ba-index.php


V. VUPEN Threat Protection Program
-----------------------------------

Governments and Intelligence agencies who are members of the VUPEN Threat
Protection Program (TPP) have been alerted about the vulnerability when it
was discovered by VUPEN, and have received a detailed detection guidance
to proactively protect national and critical infrastructures against
potential attacks exploiting this vulnerability:

http://www.vupen.com/english/services/tpp-index.php


VI. SOLUTION
----------------

Apply MS10-080 security update.


VII. CREDIT
--------------

This vulnerability was discovered by Chaouki Bekrar of VUPEN Security


VIII. ABOUT VUPEN Security
---------------------------

VUPEN is a leading IT security research company providing vulnerability
management and security intelligence solutions which enable enterprises
and institutions to eliminate vulnerabilities before they can be exploited,
ensure security policy compliance and meaningfully measure and manage risks.

Governmental and federal agencies, and global enterprises in the financial
services, insurance, manufacturing and technology industries rely on VUPEN
to improve their security, prioritize resources, cut time and costs, and
stay ahead of the latest threats.

* VUPEN Vulnerability Notification Service (VNS) :
http://www.vupen.com/english/services/vns-index.php

* VUPEN Binary Analysis & Exploits Service (BAE) :
http://www.vupen.com/english/services/ba-index.php

* VUPEN Threat Protection Program for Govs (TPP) :
http://www.vupen.com/english/services/tpp-index.php

* VUPEN Web Application Security Scanner (WASS) :
http://www.vupen.com/english/services/wass-index.php


IX. REFERENCES
----------------------

http://www.vupen.com/english/advisories/2010/2627
http://www.microsoft.com/technet/security/bulletin/ms10-080.mspx
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2010-3239


X. DISCLOSURE TIMELINE
-----------------------------

2010-04-02 - Vendor notified
2010-04-02 - Vendor response
2010-08-25 - Status update received
2010-10-12 - Coordinated public Disclosure