Secunia Research: Microsoft Excel String Parsing Integer Overflow Vulnerability

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                 Secunia Research 09/06/2009

    - Microsoft Excel String Parsing Integer Overflow  -

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Table of Contents

Affected Software…1
Severity…2
Vendor's Description of Software…3
Description of Vulnerability…4
Solution…5
Time Table…6
Credits…7
References…8
About Secunia…9
Verification…10

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1) Affected Software

• Microsoft Office Excel 2003

NOTE: Other versions may also be affected.

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2) Severity

Rating: Highly critical
Impact: System compromise
Where: Remote

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3) Vendor's Description of Software

"Microsoft Office Excel is a powerful tool you can use to create and
format spreadsheets, and analyze and share information to make more
informed decisions.".

Product Link:
http://office.microsoft.com/excel

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4) Description of Vulnerability

Secunia Research has discovered a vulnerability in Microsoft Office
Excel, which can be exploited by malicious people to compromise a
user's system.

The vulnerability is caused due to an integer overflow error when
processing the number of strings in a file and can be exploited to
cause a heap-based buffer overflow via a specially crafted Excel
file.

Successful exploitation allows execution of arbitrary code.

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5) Solution

Apply patches from MS09-021.

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6) Time Table

10/03/2009 - Vendor notified.
10/03/2009 - Vendor response.
19/05/2009 - Status update requested.
22/05/2009 - Vendor provides status update.
09/06/2009 - Public disclosure.

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7) Credits

Discovered by Carsten Eiram, Secunia Research.

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8) References

The Common Vulnerabilities and Exposures (CVE) project has assigned
CVE-2009-0561 for the vulnerability.

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9) About Secunia

Secunia offers vulnerability management solutions to corporate
customers with verified and reliable vulnerability intelligence
relevant to their specific system configuration:

http://secunia.com/advisories/business_solutions/

Secunia also provides a publicly accessible and comprehensive advisory
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http://secunia.com/advisories/mailing_lists/

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10) Verification

Please verify this advisory by visiting the Secunia website:
http://secunia.com/secunia_research/2009-12/

Complete list of vulnerability reports published by Secunia Research:
http://secunia.com/secunia_research/

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