Vulnerability identifier: #VU1366

Vulnerability risk: High

CVSSv3.1: 8.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2009-0558

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Microsoft Excel
Client/Desktop applications / Office applications
Microsoft Excel for Mac
Client/Desktop applications / Office applications

Vendor: Microsoft

Description
The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The weakness exists due to array indexing error when parsing the Excel spreadsheet file format. A remote attacker can create a specially crafted Excel file containing a malformed object record, trick the victim into opening it, trigger memory corruption and execute arbitrary code on the target system with privileges of the current user.

Successful exploitation of the vulnerability results in arbitrary code execution on the vulnerable system.

Mitigation
Install update from vendor's website:

Microsoft Office Excel 2000 Service Pack 3:
https://www.microsoft.com/downloads/details.aspx?familyid=dd16e243-b8e2-4afb-86b6-4d60214598eb
http://go.microsoft.com/fwlink/?LinkID=143568
Microsoft Office for Mac 2004:
https://www.microsoft.com/downloads/details.aspx?FamilyID=5557bfb7-ebb4-4c42-8042-41e830c4e550
http://go.microsoft.com/fwlink/?LinkID=143568
Microsoft Office for Mac 2008:
https://www.microsoft.com/downloads/details.aspx?FamilyID=58326da2-eb75-4b42-b1bc-e70319defb58
http://go.microsoft.com/fwlink/?LinkID=143568
Microsoft Office Open XML File Converter for MAC:
https://www.microsoft.com/downloads/details.aspx?FamilyID=9d6d9eaa-8442-4184-8886-faab2803bde6
http://go.microsoft.com/fwlink/?LinkId=131481

Vulnerable software versions

Microsoft Excel:

Microsoft Excel for Mac: 2004 - 2008

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External links
http://technet.microsoft.com/en-us/library/security/ms09-021.aspx

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.