RE: MS02-023 does not patch actual issue!

From: David McKenzie (DMcKenzieat_private)
Date: Thu May 16 2002 - 10:54:07 PDT

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    In addition - this patch introduces a lack of functionality in one of out
    apps:
    
    Scenario:
    
    Non-administrative user with a SSL session runs a JavaScript popup.
    When the popup window is closed, the user must reauthenticate.
    
    Behavior introduced within one of the patches in the security rollup
    
    Tested Windows 2000 IE6 and IE 5.5.
    
    PHOOEY
    
    -----Original Message-----
    From: GreyMagic Software [mailto:securityat_private]
    Sent: Thursday, May 16, 2002 3:56 AM
    To: NTBugtraq; Bugtraq; secureat_private
    Subject: MS02-023 does not patch actual issue!
    
    
    Hello,
    
    Microsoft released a cumulative patch yesterday, which, among other issues,
    allegedly patches the dialogArguments vulnerability
    (http://jscript.dk/adv/TL002/).
    
    In their bulletin Microsoft makes several severe errors:
    
    1. "A cross-site scripting vulnerability in a Local HTML Resource..."
    
    No, Microsoft, the problem is not plain cross site scripting, the problem is
    that dialogArguments' security restrictions are bypassed and it is passed to
    the dialog even though it shouldn't. Please re-read the advisories.
    
    2. "A successful attack requires that a user first click on a hyperlink.
    There
    is no way to automate an attack using this vulnerability."
    
    This is simply wrong, the user doesn't have to click anything for this issue
    to
    be exploited, it can run automatically.
    
    3. Microsoft also claims that this issue only exists in IE6.
    
    Microsoft obviously doesn't follow Bugtraq. This issue also exists in IE5
    and
    IE5.5, as we demonstrated in our GM#001-AX advisory.
    
    
    In conclusion, Microsoft did not understand the problem. They only patched a
    symptom of this vulnerability, not its root cause.
    
    As a result of that incomplete "patch" IE5 and IE5.5 are still very much
    vulnerable to this attack in other resources. For a demonstration see
    http://sec.greymagic.com/adv/gm001-ax/.
    
    We hope that Microsoft fixes the actual issue this time, and not just the
    resource file.
    
    Regards,
    	- GMS.
    



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