Microsoft Internet Explorer textNode Use-After-Free

[Scott Bell <scott.bell () security-assessment com>]

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        presents..


Microsoft Internet Explorer textNode Use-After-Free

PDF: http://security-assessment.com/files/documents/advisory/ms13_037_ie_textnode_uaf.pdf
Metasploit: http://www.security-assessment.com/files/documents/advisory/ms13_037_ie_textnode_uaf.rb

+-----------+
|Description|
+-----------+

A Use-after-free memory corruption vulnerability was identified in Microsoft Internet Explorer 8. This allows a 
malicious user to remotely execute arbitrary code on a vulnerable user’s machine, in the context of the current user. 
The memory corruption happens when the application of a style sheet performs style computations on the DOM. A DOM 
textNode pointer becomes corrupted after the style computation. This pointer is then overwritten when the innerHTML 
property on the parent object is set.


+------------+
|Exploitation|
+------------+

Exploitation of this vulnerability requires a user to visit a page containing specially crafted JavaScript. Users can 
generally be lured to visit web pages via email, instant message or links on the internet. Vulnerabilities like this 
are often hosted on legitimate websites which have been compromised by other means. Exploitation of this vulnerability 
is relatively simple. Under correct conditions, setting the innerHTML of the object results in an attacker controlled 
direct pointer overwrite. The only obstacle is having to perform heap manipulation before a ROP chain can be used.


+--------+
|Solution|
+--------+

Microsoft validated this security issue in Internet Explorer 8 and issued a patch (MS13-037) to remedy it. 
Security-Assessment.com recommends applying the patch which has been made available via Windows Update.


+-----------------------------+
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