Hello list!

I want to warn you about Denial of Service vulnerabilities in Internet
Explorer. I've found these DoS holes in IE7 already in August 2010.

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Affected products:
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Vulnerable are Internet Explorer 7 (7.00.5730.13) and other versions of IE7.
IE6 and IE8 are not affected.

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Details:
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DoS:

When a redirector with response 301, 302 or 303 and data: URI in Location
header included into a tag frame or iframe, the browser crashes (the attack
doesn't work with other 30x statuses). It happens due to access violation
(aka segmentation fault) in iexplore.exe.

Exploit:

http://websecurity.com.ua/uploads/2012/IE7%20DoS.txt

This is 302 redirector on Perl. You can make similar redirectors with 301,
302 or 303 statuses.

As 301 redirector you can use my example with data: URI at TinyURL:

http://tinyurl.com/fj4hm

The attack works from the second attempt. So it's needed to go to redirector
twice (to set URL twice in address bar, or after appearing of error page to
return to previous page in the browser).

Example of attack with this redirector via vulnerability
(http://websecurity.com.ua/4526/) at United Nations' site (they haven't
fixed it since 29.04.2010, when I've found this hole and informed UN, so you
can use it for checking purposes):

http://www.un.org/zh/documents/view_doc.asp?url=http://tinyurl.com/fj4hm

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Timeline:
------------ 

2012.11.28 - announced at my site in another publication.
2012.12.01 - disclosed at my site (http://websecurity.com.ua/6198/).

Best wishes & regards,
MustLive
Administrator of Websecurity web site
http://websecurity.com.ua