Microsoft has released a security bulletin and software updates to address the arbitrary code execution vulnerability in Office PowerPoint.
Description
Microsoft Office PowerPoint contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code with the privileges of the user.
This vulnerability is due to errors when PowerPoint files are processed. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious PowerPoint document. If successful, the attacker could execute arbitrary code with the privileges of the user.
Malicious code is actively exploiting this vulnerability.
Microsoft confirmed this vulnerability in a security bulletin and released software updates.
Warning Indicators
The following applications are vulnerable:
Microsoft Office PowerPoint 2000 SP3 and earlier Microsoft Office PowerPoint 2002 SP3 and earlier Microsoft Office PowerPoint 2003 SP3 and earlier Microsoft Office 2004 for Mac
IntelliShield Analysis
Attackers rely on user interaction to exploit this vulnerability. An attacker may attempt to convince a user to view a malicious file by providing a document as an e-mail attachment. If an exploit is successful, the attacker could execute code with the privileges of the user. If the user holds privileges equivalent to the Administrator account, the attacker could execute code that could result in a complete system compromise.
Reports indicate that targeted attempts to leverage this vulnerability have occurred. A variant of the Trojan.PPDropper trojan, which is described in IntelliShield Alert 10845, is actively exploiting this vulnerability. Details that pertain to the specific variant are not available.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the May 2009 security bulletin release. This Cisco bulletin, which assists administrators in identifying or mitigating these vulnerabilities using Cisco devices, is available at the following link: Cisco Applied Mitigation Bulletin: Microsoft Security Bulletin Release for May 2009
The update available from Microsoft corrects the vulnerability by improving the validation of memory operations.
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS09-017
Microsoft has released a security advisory at the following link: 969136
US-CERT has released a vulnerability note at the following link: VU#627331
Impact
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code with the privileges of the user. If the user holds elevated privileges, the attacker could execute arbitrary code that could result in a system compromise.
Technical Information
This vulnerability exists due to improper handling of invalid index values. The processing of malicious values within a PowerPoint file could trigger memory corruption. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious document. The attacker could leverage memory corruption resulting from the processing of the document to execute arbitrary code with the privileges of the user.
Safeguards
Administrators are advised to apply the available updates.
Users are advised not to open unsolicited files. Users should verify the authenticity of unexpected files from trusted sources before opening them.
Users are advised to run applications with the least privileges necessary.
Users may consider applying the Microsoft Office Isolated Conversion Environment (MOICE) to safely open documents from untrusted sources on systems running Microsoft Office 2003 and 2007.
Administrators may consider enabling the File Block policy to prevent PowerPoint from opening .ppt files until an update can be applied.
Patches/Software
Microsoft customers can obtain updates directly by using the links in the MS09-017 security bulletin. These updates are also distributed by Windows automatic update features and available on the Windows Update website. Microsoft Windows Server Update Services (WSUS), Systems Management Server, and System Center Configuration Manager can assist administrators in deploying software updates.
Signatures
Cisco Systems Cisco Intrusion Prevention System (IPS) 6.0
Version 2, April 3, 2009, 4:26 PM: A variant of the Trojan.PPDropper family of trojans is actively exploiting the Microsoft Office PowerPoint arbitrary code execution vulnerability.
Version 1, April 2, 2009, 7:45 PM: Microsoft Office PowerPoint contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code with the privileges of the user. Updates are not available.
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