A malicious user can create a form which is submitted by the victim (automatically using Active Scripting or manually using Social Engineering). This form can cause a non- HTTP service to echo back JavaScript commands which in turn allow the malicious user to steal the cookie for that domain. There are more uses for this attack, other than just stealing cookies.


Effects:
Internet Explorer 6 and older versions
Opera 6.0 and older versions


Severity:
Allows stealing of cookies, penetration of internal networks and other evil stuff.

Author:
Obscure^
[ obscure@eyeonsecurity.net ]

Vendor Status:
Internet Explorer - Informed secure@microsoft.com and worked with them to release a patch. Should be out soon.
Opera - Worked with the Opera team. A fix is due next release.


Web:

http://eyeonsecurity.net/papers/ - Extended HTML Form Attack


Background.

Many web browsers such as Internet Explorer allow forms to be submitted to non-HTTP services. Some non-HTTP services echo back the information sent, and the web browser renders the echo as an HTML page, regardless of the protocol behind the service.


Problem.

A malicious user can create a form which is submitted by the victim (automatically using Active Scripting or manually using Social Engineering). This form can cause a non-HTTP service to echo back JavaScript commands which in turn allow the malicious user to steal the cookie for that domain. There are more uses for this attack, other than just stealing cookies.


Exploit Example.

available at http://eyeonsecurity.net/advisories/showMyCookie.html




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