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Advisory:
Microsoft Internet Explorer DoS in Rendering Malicious PNG Files.

Version Affected:
IE 7 (7.0.5730)/ IE 8 (8.0.6001) BETA

Release Date:
17 September 2008

Background:
Mshtml.dll is a standard library which is responsible for rendering objects in web pages in Internet Explorer.

Description:
The internet explorer unable to render and load the malicious png image.On further discussion ,Microsoft team stated that CDwnTaskExec::ThreadExec enters an infinite loop that that keeps grabbing task and runs them synchronously.This results in failure in completion of task.When a task never completes,or timeouts all subsequent task will be blocked. IE will fail to load all subsequent image after an attempt to load the malicious PNG file.

Credit:
Aditya K Sood
Team Lead, www.EvilFingers.com
http://www.secniche.org

Disclaimer:
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There is no representation or warranties, either express or implied by or with respect to anything in this document, and shall not be liable for a ny implied warranties of merchantability or fitness for a particular purpose or for any indirect special or consequential damages.

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