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  3. Microsoft Excel Opcode Handling Unspecified Remote Code Execution Vulnerability

Microsoft Excel Opcode Handling Unspecified Remote Code Execution Vulnerability

Risk

High

Date Discovered

January 9, 2007

Description

Microsoft Excel is reportedly prone to an unspecified remote code-execution vulnerability. Successfully exploiting this issue allows attackers to execute arbitrary code in the context of targeted users. Note that Microsoft Office applications include functionality to embed Office files as objects contained in other Office files. As an example, Microsoft Word files may contain embedded malicious Microsoft Excel files, making Word and other Office documents another possible attack vector. Insufficient details are currently available to elaborate further.

Technologies Affected

  • Microsoft Excel 2000
  • Microsoft Excel 2002
  • Microsoft Excel 2002 SP3
  • Microsoft Excel 2003
  • Microsoft Excel Viewer 2003
  • Microsoft Office 2000
  • Microsoft Office 2000 SP1
  • Microsoft Office 2000 SP2
  • Microsoft Office 2000 SP3
  • Microsoft Office 2003
  • Microsoft Office 2003 SP1
  • Microsoft Office 2003 SP2
  • Microsoft Office 2004 for Mac
  • Microsoft Office XP
  • Microsoft Office XP SP1
  • Microsoft Office XP SP2
  • Microsoft Office XP SP3
  • Microsoft Office v. X
  • Microsoft Works Suite 2004
  • Microsoft Works Suite 2005
  • Microsoft Works Suite 2006

Recommendations

Run all software as a nonprivileged user with minimal access rights.

All non-administrative tasks should be performed as an unprivileged user with minimal access rights.

Deploy network intrusion detection systems to monitor network traffic for malicious activity.

Deploy NIDS to monitor network traffic for signs of suspicious or anomalous activity. This may help detect malicious actions that an attacker may take after successfully exploiting vulnerabilities in applications. Review all applicable logs regularly.

Do not accept or execute files from untrusted or unknown sources.

Users should never accept files from untrusted or unknown sources, because they may be malicious in nature. Avoid opening email attachments from unknown or questionable sources.

Do not follow links provided by unknown or untrusted sources.

Users should avoid websites of questionable integrity. Never follow links supplied by unknown or untrusted sources.

Implement multiple redundant layers of security.

Since this issue may be leveraged to execute code, we recommend memory-protection schemes, such as non-executable stack/heap configurations and randomly mapped memory segments. This tactic may complicate exploits of memory-corruption vulnerabilities.
Microsoft has released fixes to address this issue. Please see the references section for more information. Update: Microsoft has re-released MS07-002 to resolve a regression with the original Excel 2000 fixes when dealing with files created when in Korean, Chinese, or Japanese executable modes. Please see the knowledge base article (KB931183) for further information.

Credits

Jie Ma discovered this vulnerability.
Copyright © Symantec Corporation.
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from secure@symantec.com.

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.
Symantec, Symantec products, Symantec Security Response, and secure@symantec.com are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.

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