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CERT Coordination Center

Microsoft Internet Explorer 8 use-after-free vulnerability

Vulnerability Note VU#427980

Original Release Date: 2011-01-06 | Last Revised: 2011-01-10


Microsoft Internet Explorer 8 is susceptible to a use-after-free vulnerability in the mshtml.dll library.


The use-after-free vulnerability is triggered when handling circular memory references. Full details of the crash can be found at Michal Zalewski's website. Additional details about the fuzzer used to find this vulnerability can be found at Michal Zalewski's blog.


An attacker can cause the browser to crash and may be able to execute arbitrary code as the user.


We are currently unaware of a practical solution to this problem.

Internet Explorer users should take advantage of the mitigations provided in Microsoft's Enhanced Mitigation Experience Toolkit.

Vendor Information

Affected   Unknown   Unaffected

Microsoft Corporation

Updated:  January 06, 2011



Vendor Statement

No statement is currently available from the vendor regarding this vulnerability.

Vendor Information

We are not aware of further vendor information regarding this vulnerability.

CVSS Metrics

Group Score Vector
Base N/A N/A
Temporal N/A N/A
Environmental N/A



This vulnerability was reported to the public by Michal Zalewski.

This document was written by Jared Allar.

Other Information

CVE IDs: CVE-2011-0346
Severity Metric: 1.11
Date Public: 2011-01-01
Date First Published: 2011-01-06
Date Last Updated: 2011-01-10 12:28 UTC
Document Revision: 13

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