The VUPEN Vulnerability Research Team discovered a critical vulnerability in Microsoft Internet Explorer. The vulnerability is caused by a use-after-free error in the "CSpliceTreeEngine::InsertSplice()" function within the MSHTML library when handling layouts, which could be exploited by remote attackers to compromise a vulnerable system by tricking a user into visiting a specially crafted web page. Versions 6 and 7 are affected.
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iDefense Security Advisory 04.12.11 - Remote exploitation of a use-after-free vulnerability in Microsoft Corp.'s Internet Explorer could allow an attacker to execute arbitrary code with the privileges of the current user. The vulnerability occurs when an object is exchanged during a call to a certain function. The object's memory is freed, however a reference to the object remains. When the reference is later used to access the object, this now invalid memory is treated as a valid object and one of the object members is used to make an indirect function call. This may result in the execution of arbitrary code. Internet Explorer versions 6 and 7 are vulnerable.
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