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

ID ZDI-15-654
Type zdi
Reporter B6BEB4D5E828CF0CCB47BB24AAC22515
Modified 2016-11-09T00:00:00


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 vulnerability relates to how Internet Explorer keeps track of @font-face rules in CSS stylesheets. By manipulating a document's elements an attacker can force a CFontFace object in memory to be reused after it has been freed. An attacker can leverage this vulnerability to execute code under the context of the current process.