internet explorer local file reading

From: jelmer (jelmerat_private)
Date: Mon Feb 03 2003 - 06:25:10 PST

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     We allready knew pressing the back button on IE is dangerous
    (http://online.securityfocus.com/archive/1/267561)  So it wont come as a
    total shock
    that so is clicking a link :)
    The problem lies in the dragdrop method that was added as a method on
    nearly all HTML elements in ie5.5 This method makes any element act like its
    being dragged.
    
    It is possible to abuse this behaviour to drop text in a html upload control
    thus
    allowing you to read any file from an unsuspecting users harddisk. In order
    for it to
    be succesfull the name of the file must be known
    
    basicly drag and dropping text takes a couple of steps
    
    - select text
    - press mouse
    - move mouse over over an element that can accept it
    - release mouse.
    
    It is possible to mimic all the above steps but the pressing of the button
    by using
    javascript
    
    a demo is provided at
    
    http://kuperus.xs4all.nl/security/ie/xfiles.htm
    
    it isn't very elegant but seems to work most of the time (ie acts a little
    flakey at times),
    there  are probably better ways to do it  if you know of any let me know ;)
    
    
    it was tested on ie 6 sp1 + all patches
    
    Microsoft was notified a couple of days back, haven't recieved anything back
    yet
    
    If you want to protect yourself against this disable active scripting
    
    
    references:
    
    http://webreference.com/programming/javascript/dragdropie/3.html
    http://msdn.microsoft.com/workshop/author/dhtml/reference/methods/dragdrop.a
    sp
    



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