Microsoft Internet Explorer CDOMTextNode Use-After-Free Remote Code Execution Vulnerability

2013-05-30T00:00:00
ID ZDI-13-103
Type zdi
Reporter Stephen Fewer of Harmony Security (www.harmonysecurity.com)
Modified 2013-11-09T00:00:00

Description

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 is due to the way mshtml handles a CDOMTextNode. When using a selection to get focusNode, the process can be made to create a CDOMTextNode and later delete this CDOMTextNode resulting in a dangling pointer. The process can be later forced to reuse this pointer resulting in a use-after-free condition. An attacker can leverage this situation to execute code under the context of the user running the browser.