Re: XSS question.

From: VAM (thebigbadwolfat_private)
Date: Thu Dec 05 2002 - 13:17:42 PST

  • Next message: zeno: "Re: XSS question."

    Thanks Zeno,
    
    On Thu, 5 Dec 2002 14:23:36 -0500 (EST), "zeno" <bugtraqat_private>
    said:
    > If the server escapes everything (example <b>hi</b> becomes
    > \<b\>hi\<\\b\>) 
    > then you can't xss with the script method.
    
    This server (Webster web server) does not escapes like you mention above,
    but converts all '/'s into '\'.. so </script> becomes useless.
    
    > As far as the browser leaving %20
    > no it won't execute. using + instead of %20 also will not work.
    
    Right.. 
    
    > If you
    > can manage
    > to get the xss hole between a <script>  
    > 
    > example
    > 
    > <script>
    > $variable-vuln-to-xss
    > </script> 
    > 
    > then it would be possible.
    
    In this case, </script> isn't helping.. Mozilla/IE do not seem to honor
    <\script> in the response. When the same response is changed to
    </script>, the script does get executed.
    
    > Obviously script isn't the only method to call
    > javascript.
    
    I am looking for ways other than <script>...</script> and <img
    src=javascript:...> to run javascripts. Any ideas on that?
    
    > When
    > you encode the entire string does it leave it or attempt any type of
    > translation back?
    > 
    > (aka does it simply not translate %20 or does it do this to every
    > character?)
    > 
    
    All %xx s are left as they are in the response.. so they become pretty
    much useless..
    
    > 
    > - zenoat_private
    > 
    
    Thanks,
    VAM.
    
    > 
    > 
    > > 
    > > Hey I am trying to figure out a way to exploit a webserver that is
    > > supposedly vulnerable to XSS. The issues are:
    > > 1. </SCRIPT> gets converted into <\SCRIPT> in the server response.. for
    > > ScrIPT, etc too..
    > > 2. img%20src remains img%20src in the response.. (the server does no
    > > decoding)
    > > 
    > > so, I am not able to make IE/others execute the javascript embedded in
    > > there. Is there any other way/ways of invoking javascript in the HTML
    > > response from the server.. e.g. any other single-worded HTML tag etc that
    > > can do something like what <img src=javascript:alert("hello")> does.. ?
    > > 
    > > Thanks!
    > > 
    > 
    > 
    



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