iDefense Security Advisory 02.12.08
http://labs.idefense.com/intelligence/vulnerabilities/ 
Feb 12, 2008

I. BACKGROUND

Internet Explorer is a graphical web browser developed by Microsoft
Corp. that has been included with Microsoft Windows since 1995. For
more information about Internet Explorer, visit following URL.

http://www.microsoft.com/ie/ 

II. DESCRIPTION

Remote exploitation of a memory corruption vulnerability in Microsoft
Corp.'s Internet Explorer web browser allows attackers to execute
arbitrary code within the context of the affected user.

When certain properties are assigned malformed values, memory can be
corrupted in a way that leads to Internet Explorer making a call to a
member function of an already released property object. If the memory
location of the released property object happens to be filled by
attacker controlled content, the attacker can execute arbitrary code.

III. ANALYSIS

Exploitation of this vulnerability would allow an attacker to execute
arbitrary code in the context of the user running Internet Explorer. In
order to be successful, a targeted user must render a maliciously
crafted web page.

On Vista, Internet Explorer 7 runs in Protected Mode, which has less
privileges than a normal user. It somewhat mitigates the impact of this
vulnerability, but does not prevent arbitrary code execution.

IV. DETECTION

iDefense testing shows that Internet Explorer 6.0 and Internet Explorer
7.0, with all available security patches as of October 22nd, 2007, are
vulnerable. Older versions of Internet Explorer may also be vulnerable.

V. WORKAROUND

Disabling active scripting for the Internet Zone can effectively
mitigate this issue.

VI. VENDOR RESPONSE

Microsoft has officially addressed this vulnerability with Security
Bulletin MS08-010. For more information, consult their bulletin at the
following URL.

http://www.microsoft.com/technet/security/Bulletin/ms08-010.mspx 

VII. CVE INFORMATION

The Common Vulnerabilities and Exposures (CVE) project has assigned the
name CVE-2008-0077 to this issue. This is a candidate for inclusion in
the CVE list (http://cve.mitre.org/), which standardizes names for 
security problems.

VIII. DISCLOSURE TIMELINE

10/24/2007  Initial vendor notification
10/24/2007  Initial vendor response
02/12/2008  Coordinated public disclosure

IX. CREDIT

This vulnerability was reported to VeriSign iDefense by hyy.

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X. LEGAL NOTICES

Copyright =A9 2008 iDefense, Inc.

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Disclaimer: The information in the advisory is believed to be accurate
at the time of publishing based on currently available information. Use
of the information constitutes acceptance for use in an AS IS condition.
 There are no warranties with regard to this information. Neither the
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