Topic: Microsoft Excel COLINFO Record Buffer Overflow Vulnerability

Release Date: 2006-07-12

CVE CAN ID : CVE-2006-1304

Affected system:
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-Microsoft Excel 2000
-Microsoft Excel XP
-Microsoft Excel 2003

Unaffected system:
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Impact:
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NSFocus Security Team discovered a buffer overflow vulnerability in Microsoft Excel's processing of COLINFO record, which allows remote attackers to run arbitrary via carefully crafted Excel files.

Description:
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Excel does not perform sufficient check for certain field when processing COLINFO record, which might cause a buffer overflow vulnerability in data filling operation. Attackers can run arbitrary via carefully craft data.

Attackers can craft an Excel file with malformed COLINFO record and allure users to open it via instant messaging tools, e-mail or other vectors, resulting in arbitrary code execution with the privilege of the user. If the user is the administrator, then attackers might take complete control over the system.

Workaround:
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Do not open any Excel file from untrusted sources.

Vendor Status:
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2006.03.30 Informed the vendor
2006.04.03 Vendor confirmed the vulnerability
2006.07.11 Microsoft has released a security bulletin (MS06-037) and related patches.

For more details about the security bulletin, please refer to:
http://www.microsoft.com/technet/security/bulletin/MS06-037.mspx

Additional Information:
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The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2006-1304 to this issue. This is a candidate for inclusion in the CVE list (http://cve.mitre.org), which standardizes names for security problems. Candidates may change significantly before they become official CVE entries.

Credit:
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Wen Yujie of NSFocus Security Team found the vulnerability.