Fortinet Security Advisory: FSA-2006-09

[Fortinet Research <vulnmoniter () fortinet com>]

Fortinet Security Advisory: FSA-2006-09

Microsoft Excel Formula Size Stack Overflow

Advisory Date      : March 14, 2006                     
Reported Date      : January 24, 2006
Vendor             : Microsoft                  
Affected Products  : Microsoft Excel 2003 Chinese Version
                     Windows XP Home Edition Chinese Version and 
                     possible all versions of Microsoft Excel.
Severity           : High
Reference          : http://www.microsoft.com/technet/security/Bulletin/MS06-012.mspx
                     http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-0029
                     http://www.securityfocus.com/bid/15780
                   
Description        :  Fortinet Security Research Team (FSRT) has discovered a Improper Stack  Overflow Vulnerability in 
the Microsoft Excel software. This vulnerability is due to Microsoft Excel's manipulation of opcode 0x0218, when 
provided with a large Formula Size, it will cause a stack overflow. An remote attacker could construct a .xls file and 
put it on controlled web site. When the user opens the .xls file with Microsoft Internet Explorer, the browser will 
call Microsoft Excel to open the .xls file automatically, and this will cause Microsoft Excel to crash. If excel file 
is specially crafted, it may allow attackers to execute arbitrary code on the affected system.

Impact             : Execution of arbitrary code leading to system compromise.

Solution           : Microsoft has released a update for this vulnerability, which is available for downloading from 
Microsoft web site, see reference. 

Fortinet Protection: FortiGate series of security systems have been updated to detect exploits targeting this 
vulnerability.

Acknowledgment     : Dejun Meng of Fortinet Security Research team found this vulnerability. 

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assumes no legal responsibility for the accuracy or completeness of the information. More specific information is 
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