iDefense Security Advisory 08.12.08
http://labs.idefense.com/intelligence/vulnerabilities/ 
Aug 12, 2008

I. BACKGROUND

Microsoft Corp.'s PowerPoint Viewer is a viewer for full-featured
presentations created in PowerPoint 97 and later versions. PowerPoint
Viewer 2003 is freely downloadable from Microsoft's website at the
following URL.

http://www.microsoft.com/downloads/details.aspx?FamilyId=428D5727-43AB-4F24-90B7-A94784AF71A4 

II. DESCRIPTION

Remote exploitation of an integer overflow vulnerability in Microsoft
Corp.'s PowerPoint Viewer 2003 could allow an attacker to execute
arbitrary code in the context of the user running the application.

This vulnerability specifically exists when handling CString objects
embedded in a PowerPoint presentation file. An issue in this object
results in a very small amount of buffer being allocated while a very
large amount of data is copied into it. This leads to an exploitable
heap-based buffer overflow.

III. ANALYSIS

Exploitation allows an attacker to execute arbitrary code in the context
of a user opening a malicious presentation using Microsoft PowerPoint
Viewer 2003. In order to exploit this vulnerability, an attacker must
persuade, or otherwise force, a targeted user to open such a document.
This could be accomplished using a direct URL, an e-mail, an instant
message, or even by hijacking a trusted site.

IV. DETECTION

iDefense has confirmed that pptview.exe file version 11.0.5703.0 and
file version 11.0.6566.0, as included in Microsoft Office 2003 SP2, are
vulnerable. Other versions are also likely to be affected.

Version 11.0.8164.0 of pptview.exe, as included in Microsoft Office 2003
SP3, does not appear to be affected.

V. WORKAROUND

iDefense is currently unaware of any effective workaround for this
issue.

VI. VENDOR RESPONSE

Microsoft has officially addressed this vulnerability with Security
Bulletin MS08-051. For more information, consult their bulletin at the
following URL.

http://www.microsoft.com/technet/security/bulletin/ms08-051.mspx 

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2008-0120 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for 
security problems.

VIII. DISCLOSURE TIMELINE

09/28/2007  Initial vendor notification
09/28/2007  Initial vendor response
08/12/2008  Coordinated public disclosure

IX. CREDIT

This vulnerability was reported to iDefense by Ruben Santamarta from
Reversemode.com.

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X. LEGAL NOTICES

Copyright =A9 2008 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
 There are no warranties with regard to this information. Neither the
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