Re: Cross site scripting in almost every mayor website

From: Berend-Jan Wever (skylinedat_private)
Date: Sun Apr 21 2002 - 03:49:44 PDT

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     ('binary' encoding is not supported, stored as-is)
    Been there, done that.
    
    I have successfully created a worm and tested it 
    before trying to report this to McAfee, they do the 
    vrus scanning for hotmail. I got a "you are not a 
    registered user" auto-reply and they ignored my 
    messages because I wasn't in their files ;( too bad 
    for them.
    You do have full access to the DOM of Hotmail 
    when you can find a way to cross-site script, thus 
    allowing you full access to the inbox, address 
    book etc...
    
    BJ
    ----- Original Message ----- 
    From: FozZy 
    To: bugtraqat_private 
    Cc: skylinedat_private ; vuln-
    devat_private 
    Sent: Sunday, April 21, 2002 3:53
    Subject: Re: Cross site scripting in almost every 
    mayor website
    
    
    To webmail developpers : there is something 
    interesting for you hidden in this post. The 
    Hotmail problem was a "evil html filtering" problem 
    in incoming e-mails. It was possible to bypass the 
    filter by injecting javascript with XML, when 
    parsed with IE.  See :
    http://spoor12.edup.tudelft.nl/SkyLined/docs/ie.hot
    mail.howto.css.html
    
    *** I guess that many other webmails are 
    vulnerable to this attack. ***
    
    I verified that Yahoo is vulnerable with IE 5.5 (but 
    they have other bugs and they don't care, see 
    http://online.securityfocus.com/archive/1/265464). 
    I did not checked other webmails, but I am sure 
    almost every one can be cracked this way.
    
    > The fix: as far as I could find out they now 
    replace 
    > the properties 'dataFld', 'dataFormatAs' 
    > and 'dataSrc' of any HTML tag 
    > with 'xdataFld', 'xdataFormatAs' and 'xdataSrc' 
    to 
    > prevent XML generation of HTML alltogether.
    
    The implication of executing javascript is that an 
    incoming email can control the mailbox of the 
    user.  It is also possible to send the session 
    cookie to a cgi script and read remotely all the e-
    mails. (BTW, it is still possible to do that on 
    Hotmail and on almost every webmail, since they 
    don't check the IP address, even without this XML 
    trick cause their filters are sooo bad) 
    I fear that a cross-platform and cross-site webmail 
    worm deleting all the emails and spreading could 
    appear in the near future. Please Hotmail Yahoo 
    & co, do something before it comes true... 
    
    FozZy
    
    Hackademy / Hackerz Voice
    http://www.dmpfrance.com/inted.html
    



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