Microsoft Office Excel contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code with the privileges of the user. Updates are available.
Description
Microsoft Office Excel contains a vulnerability that could allow an unauthenticated, remote attacker to execute arbitrary code.
The vulnerability exists due to improper validation of malformed records within Excel documents. An unauthenticated, remote attacker could exploit the vulnerability by convincing a user to view a malicious document. If the user views the file, 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.
Warning Indicators
Microsoft Office Excel 2002 SP3 and prior is vulnerable.
IntelliShield Analysis
Attackers cannot directly exploit this vulnerability and instead must rely upon user interaction to accomplish an exploit. The attacker may provide a document to a user as an attachment to an e-mail message or provide links to the user within e-mail or instant messages that direct the user to a document posted on a website. The attacker may use social engineering techniques in an attempt to convince the user to view a provided document, possibly by making the document seem to originate from a trusted source.
If the user opens the document, the attacker could trigger the execution of arbitrary code with the privileges of the user. Systems that limit user privileges likely have a reduced impact in the event of an exploit, as any code execution would occur in a restricted security context. However, on systems where users run applications with elevated privileges, an exploit could result in a complete compromise.
The Cisco Applied Intelligence team has created an Applied Mitigation Bulletin to address vulnerabilities that Microsoft disclosed in the March 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 March 2010
Vendor Announcements
Microsoft has released a security bulletin at the following link: MS10-017
Impact
An unauthenticated, remote attacker could exploit this vulnerability to execute arbitrary code with the privileges of the user. If that user holds elevated privileges, the attacker could execute code resulting in a complete system compromise.
Technical Information
The vulnerability exists due to improper validation of malformed records within Excel documents. An unauthenticated, remote attacker could exploit this vulnerability by convincing a user to open a malicious document within Excel. When opened, the document could trigger an error that the attacker could leverage to execute arbitrary code with the privileges of the user.
Safeguards
Administrators are advised to apply the available software updates.
Users are advised not to open unsolicited e-mail attachments. Users should verify that attachments are safe before opening them.
Users are advised to run applications with the least privileges possible.
Administrators may consider using the Microsoft Baseline Security Analyzer (MBSA) scan tool to identify common security misconfigurations and missing security updates on system endpoints.
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
Associated Products:
Microsoft, Inc.
Office
XP (2002) Base, SP1, SP2, SP3
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