Multiples Nexon Games - Unquoted Path Privilege Escalation

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# Exploit Title: Multiples Nexon Games - Privilege Escalation Unquoted path vulnerabilities
# Date: 13/05/2016
# Exploit Author : Cyril Vallicari
# Vendor Homepage: http://www.nexon.net/
# Softwares Links: http://dirtybomb.nexon.net/ (DirtyBomb)
#                               http://store.steampowered.com/app/273110/ (CSNZ)
# Versions: Dirty Bomb r56825 USA_EU / CSNZ : 0.0.18845.1
# Tested on: Windows 7 x64 SP1 (but it should works on all windows version)

Description : Multiples Nexon Game, including but not limited to Dirty Bomb
and Counter-Strike Nexon : Zombies,  are Prone to unquoted path
vulnerability. They fail to quote correctly the command that call for
BlackXcht.aes, which is a part of the anti-cheat system (Nexon  Game
Security). Probably all Nexon games calling this file are affected.

This could potentially allow an authorized but non-privileged local user to
execute arbitrary code with elevated privileges on the system.

POC :

Put a software named Program.exe in C:

Launch the game via steam

When BlackXcht.aes is called, Program.exe is executed with same rights as
steam

POC video : https://www.youtube.com/watch?v=wcn62GGwtcQ

Patch :

Patch for Dirty bomb - Upgrade to r57457 USA_EU
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