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ZDI-11-290 : Microsoft Internet Explorer SetExpandedClipRect Remote
Code Execution Vulnerability
http://www.zerodayinitiative.com/advisories/ZDI-11-290
October 15, 2011

- -- CVE ID:
CVE-2011-2001

- -- CVSS:
7.5, AV:N/AC:L/Au:N/C:P/I:P/A:P

- -- Affected Vendors:

Microsoft



- -- Affected Products:

Microsoft Internet Explorer



- -- TippingPoint(TM) IPS Customer Protection:
TippingPoint IPS customers have been protected against this
vulnerability by Digital Vaccine protection filter ID 11740.
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 Internet Explorer. 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 mshtml.dll and is a logic bug in the way
it handles the 'extra size index' in certain CDispNode classes within
the SetExpandedClipRect function. When the 'extra size index' is zero,
the code fails to correctly adjust the class instance pointer before and
uses the vftable pointer as a flag field. This corrupts the vftable
pointer and can lead to remote code execution under the context of the
current user. This issue is closely related to CVE-2009-3672.

- -- Vendor Response:

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

http://technet.microsoft.com/en-us/security/bulletin/ms11-081



- -- Disclosure Timeline:
2011-07-21 - Vulnerability reported to vendor
2011-10-15 - Coordinated public release of advisory

- -- Credit:
This vulnerability was discovered by:

* Anonymous



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