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Microsoft Internet Explorer 11 Garbage Collector Attribute Type Confusion Vulnerability



Internet Explorer is a graphical web browser developed by Microsoft Corp. For more information about Internet Explorer, please the visit following website:


Remote exploitation of a Type Confusion vulnerability in Microsoft Corp.'s Internet Explorer (IE) 11 could allow an attacker to execute arbitrary code with the privileges of the current user. A type confusion vulnerability exists within IE. This vulnerability can be triggered by manipulating the HTML elements within a website using javascript. Specifically, the error occurs in the 'way Javascript's Garbage Collector confuses an object of a certain type to be of another type and erroneously accesses beyond its size in memory. This condition can cause memory corruption, leading to the execution of arbitrary code.


EExploitation of this vulnerability results in the execution of arbitrary code with the privileges of the current user. To exploit this vulnerability, an attacker must entice a targeted user to visit a specially crafted Web page. An attacker typically accomplishes this via social engineering or injecting content into compromised, trusted sites. After a user visits the malicious Web page, no further user interaction is needed. An attacker can exploit this vulnerability by manipulating the heap layout of the browser and triggering the vulnerability. To exploit this vulnerability, an attacker must control the memory that has been freed prior to triggering a call to free that memory again. Heap spraying can be used to obtain control of the necessary memory. If successful, the attacker would be able to execute arbitrary code with the privileges of the current user.iDefense recommends configuring the affected application to use the exploitation mitigation methods that Microsoft's Enhanced Mitigation Experience Toolkit (EMET) tool provides. The EMET will not prevent exploitation but is effective against most known exploitation methods and will make exploitation more complex. iDefense considers this vulnerability to be of HIGH severity due to the possibility of arbitrary code execution with minimal user interaction.


The following vendors include susceptible software within their respective software distributions:

  • Microsoft microsoft: internet_explorer 11, 9, 10, 11


iDefense is unaware of any workaroundfor this vulnerability.


Microsoft has released a fix which addresses this issue. For more information, consult their advisory at the following URL:


The Common Vulnerabilities and Exposures (CVE) project has assigned the name CVE-2016-0199 to this issue. This is a candidate for inclusion in the CVE list (, which standardizes names for security problems.


01/20/2016 Initial Vendor Notification
02/25/2016 Initial Vendor Reply
06/14/2016 Coordinated Public Disclosure


This vulnerability was reported to iDefense by Skylined

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Copyright © 2016 Verisign, Inc.

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