ZDI-11-121: Microsoft Office XP Data Validation Record Parsing Remote Code Execution Vulnerability

http://www.zerodayinitiative.com/advisories/ZDI-11-121

April 12, 2011

-- CVE ID:
CVE-2011-0105

-- CVSS:
10, (AV:N/AC:L/Au:N/C:C/I:C/A:C)

-- Affected Vendors:
Microsoft

-- Affected Products:
Microsoft Office Excel

-- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 11033. 
For further product information on the TippingPoint IPS, visit:

    http://www.tippingpoint.com

-- Vulnerability Details:
This vulnerability allows remote attackers to execute arbitrary code on
vulnerable installations of Microsoft Office Excel. User interaction is
required to exploit this vulnerability in that the target must visit a
malicious page or open a malicious file.

The specific flaw exists within the application's parsing of a
particular record within a Microsoft Excel Compound Document. When
specifying a particular value, the application will fail to initialize a
variable that is used as the length of a memcpy operation. Due to the
usage of the uninitialized value, with proper control of the program
flow an attacker can force a length of their own choosing for the memcpy
operation. This will cause a buffer overflow and can lead to code
execution under the context of the application.

-- Vendor Response:
Microsoft has issued an update to correct this vulnerability. More
details can be found at:

http://www.microsoft.com/technet/security/bulletin/ms11-021.mspx

-- Disclosure Timeline:
2010-10-18 - Vulnerability reported to vendor
2011-04-12 - Coordinated public release of advisory

-- Credit:
This vulnerability was discovered by:
    * Aniway (Aniway.Anyway AT gmail DOT com)

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