Public Vulnerability Reports

Microsoft PowerPoint PPT95 Import Multiple Stack Buffer Overflow Vulnerabilities



Microsoft PowerPoint is a presentation program that comes with Microsoft Office. For more information consult the vendor's site at the following URL.


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

The vulnerabilities exist within the importer for PowerPoint 95 format files. This functionality is contained within the PP7X32.DLL.

The vulnerabilities occur when reading sound data from a PowerPoint file. In both cases, a value representing a record length is read in from the file. This value is then used to control the number of bytes read into a fixed size stack buffer. There is no check performed to ensure that the buffer can hold the number of bytes specified, which results in a stack buffer overflow.


Exploitation of these vulnerabilities results in the execution of arbitrary code with the privileges of the user opening the file. To exploit these vulnerabilities, an attacker needs to convince a user to open a malicious file. After opening the file, no further interaction is needed to trigger the vulnerability.

Since the vulnerabilities are stack based buffer overflows, and it is possible to overwrite SEH handlers stored on the stack, exploitation is relatively simple.


iDefense has confirmed the existence of these vulnerabilities in Office XP SP3, and Office 2000 SP3.


Use the cacls program to deny access to the DLL containing the vulnerable code, PP7X32.DLL. This will prevent the vulnerable DLL from loading in PowerPoint, which will also prevent users from importing PowerPoint 95 files.


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-2009-1129 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


04/25/2008 - Initial Contact
04/25/2008 - Initial Response
04/25/2008 - PoC Sent
07/22/2008 - Status Update Requested
07/23/2008 - Initial Response - Update planned in November
12/11/2008 - Status Update Received - no estimated release date
02/19/2009 - Status Update Received - new case manager, estimated release date 06/09/2009
05/12/2009 - Coordinated Public Disclosure


This vulnerability was reported to iDefense by Marsu.

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