Public Vulnerability Reports

Microsoft PowerPoint 4.2 Conversion Filter Stack Overflow



Microsoft PowerPoint is an application used for constructing presentations, and comes with the Microsoft Office Suite. For more information, see the vendor's site found at the following link.


Remote exploitation of a stack based buffer overflow vulnerability in Microsoft Corp.'s PowerPoint could allow an attacker to execute arbitrary code with the privileges of the current user.

In particular, there is code that parses a string in the PowerPoint file. If the size of this data is greater than a certain value, then memory corruption will occur. This memory corruption can lead to the vulnerable code executing an attacker supplied address.


Exploitation of this vulnerability results in the execution of arbitrary code with the privileges of the user opening the file. To exploit this vulnerability, an attacker needs to convince a user to open a malicious file.


iDefense has confirmed the existence of these vulnerabilities in the following versions of PowerPoint:

* PowerPoint 2000 SP3

* PowerPoint XP SP3

PowerPoint 2003 SP2 and SP3 contain the vulnerable code, but by default are unable to open PowerPoint 4.2 formatted files. This is due to the Office 2003 SP2/SP3 File Block Policy, which limits the file formats that Office applications will open without special permissions. If the targeted user has disabled the File Block Policy settings in PowerPoint 2003 SP3, then they are vulnerable. However, this is a non-default configuration. More on this policy can be found at the following URL.

Office 2007 and Office 2007 SP1 are not vulnerable to these issues.


Use the cacls program to deny access to the DLL containing the vulnerable code, PP4X32.DLL. This will prevent the vulnerable DLL from loading in PowerPoint, which will also prevent users from importing PowerPoint 4.0 files. If Office 2003 SP3 is being used, then the default behavior is to block the opening of PowerPoint 4.0 files. If the default behavior has been changed, restoring it is an effective workaround.


Microsoft has released a patch which addresses this issue. For more information, consult their advisory at the following URL:


The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2009-0226 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


12/03/2008 - Initial Contact
12/03/2008 - Initial Response
12/03/2008 - PoC Requested
12/15/2008 - PoC Sent
01/06/2009 - Vendor Assigned Case #
01/20/2009 - Vendor set tentative disclosure date of 06/09/2009
05/12/2009 - Coordinated Public Disclosure


This vulnerability was reported to iDefense by Marsu.

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