-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 iDefense Security Advisory 05.12.09 http://labs.idefense.com/intelligence/vulnerabilities/ May 12, 2009 I. BACKGROUND Microsoft PowerPoint is a presentation program that comes with Microsoft Office. For more information consult the vendor's site at the following URL. http://office.microsoft.com/powerpoint II. DESCRIPTION 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. III. ANALYSIS 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. IV. DETECTION iDefense has confirmed the existence of these vulnerabilities in Office XP SP3, and Office 2000 SP3. V. WORKAROUND 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. VI. VENDOR RESPONSE Microsoft has released a patch which addresses this issue. For more information, consult their advisory at the following URL: http://www.microsoft.com/technet/security/Bulletin/MS09-017.mspx VII. CVE INFORMATION 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 (http://cve.mitre.org/), which standardizes names for security problems. VIII. DISCLOSURE TIMELINE 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 IX. CREDIT This vulnerability was reported to iDefense by Marsu. Get paid for vulnerability research http://labs.idefense.com/methodology/vulnerability/vcp.php Free tools, research and upcoming events http://labs.idefense.com/ X. LEGAL NOTICES Copyright © 2009 iDefense, Inc. Permission is granted for the redistribution of this alert electronically. It may not be edited in any way without the express written consent of iDefense. If you wish to reprint the whole or any part of this alert in any other medium other than electronically, please e-mail customerservice@xxxxxxxxxxxx for permission. 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 author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.7 (MingW32) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org iD8DBQFKCfQmbjs6HoxIfBkRAg2aAKD6Ed9Q3/BZPphQ574YEHSb0RPe1gCeIQjz AReaYV9sERVhFU9HWcf44LI= =j02z -----END PGP SIGNATURE-----
