Microsoft Office Excel contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code. Updates are available.
Description
Microsoft Office Excel contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code.
This vulnerability exists due to errors in processing string variables within Microsoft Excel files. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to view a malicious Excel file. If successful, the attacker could execute arbitrary code with the privileges of the user.
Microsoft has confirmed this vulnerability in a security bulletin and released software updates that correct it.
Warning Indicators
Microsoft Office Excel 2002 SP3 and prior and Office 2004 for Mac are vulnerable.
IntelliShield Analysis
To exploit this vulnerability, an attacker must convince a user to view a malicious Excel document. The attacker may include documents as attachments to e-mail messages sent directly to users, or include links within e-mail or instant messages. Attackers will also likely use social engineering techniques in an attempt to convince users to open provided documents. If the user opens the file, the vulnerability may be triggered, allowing the attacker to execute arbitrary code.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the June 2010 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 June 2010
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS10-038
Impact
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code with the privileges of the user. If that user holds Administrator privileges, the attacker could execute code resulting in a complete compromise.
Technical Information
This vulnerability exists due to errors in processing string variables within Microsoft Excel files. An unauthenticated, remote attacker could exploit this vulnerability by creating a malicious document and convincing a user to view it. When opened, the document could trigger memory corruption, which the attacker could leverage to execute arbitrary code with the privileges of the user.
Safeguards
Administrators are advised to apply the appropriate updates.
Users are advised not to open e-mail messages from suspicious or unrecognized sources. If users cannot verify that links or attachments included in e-mail messages are safe, they are advised not to open them.
Users are advised to run applications with the least necessary privileges.
Users may consider applying the Microsoft Office Isolated Conversion Environment (MOICE) to safely open Word, Excel, and PowerPoint files from suspicious or unrecognized sources on systems that are running Microsoft Office 2003 or Office 2007.
Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.
Administrators are advised to monitor critical systems.
Patches/Software
Microsoft customers can obtain updates directly by using the links in the 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
The security vulnerability applies to the following combinations of products.
Primary Products:
Microsoft, Inc.
Excel
2002 (XP) Base, SP1, SP2, SP3
Microsoft, Inc.
Office for Mac
2004 Base
Associated Products:
Microsoft, Inc.
Office
XP (2002) Base, SP1, SP2, SP3
Alerts and bulletins on the Cisco Security Intelligence Operations Portal are highlighted by analysts in the
Cisco Threat Operations Center and represent a subset of the comprehensive content that is available through Cisco Security IntelliShield Alert Manager Service.
This customizable threat and vulnerability alert service provides security staff with access to timely, accurate, and credible information about threats and vulnerabilities that may affect their environment. Cisco is pleased to offer a free trial of the service.
To register for full access, please visit the IntelliShield trial registration page.
LEGAL DISCLAIMER The urgency and severity ratings of this alert are not tailored to individual users; users may value alerts differently based upon their network configurations and circumstances. THE ALERT, AND INFORMATION CONTAINED THEREIN, ARE PROVIDED ON AN "AS IS" BASIS AND DO NOT IMPLY ANY KIND OF GUARANTEE OR WARRANTY, INCLUDING THE WARRANTIES OF MERCHANTABILITY OR FITNESS FOR A PARTICULAR USE. YOUR USE OF THE ALERT, AND INFORMATION CONTAINED THEREIN, OR MATERIALS LINKED FROM THE ALERT, IS AT YOUR OWN RISK. INFORMATION IN THIS ALERT AND ANY RELATED COMMUNICATIONS IS BASED ON OUR KNOWLEDGE AT THE TIME OF PUBLICATION AND IS SUBJECT TO CHANGE WITHOUT NOTICE. CISCO RESERVES THE RIGHT TO CHANGE OR UPDATE ALERTS AT ANY TIME.
