Minecraft Launcher:     https://minecraft.net
Version:                1.6.61
By Ross Marks:          http://www.rossmarks.co.uk
Exploit-db:             https://www.exploit-db.com/author/?a=8724
Category:               Local
Tested on:              Windows 10 x86/x64
 
1) Insecure File Permissions Local Privilege Escalation
 
Minecraft's launcher (minecraftLauncher.exe) suffers from an elevation of privileges 
vulnerability which can be used by a simple user that can change the executable file 
with a binary of choice. The vulnerability exist due to the improper permissions,
with the 'F' flag (Full) for 'Users' group, making the entire directory 
'Minecraft' and its files and sub-dirs world-writable.

This would allow an attacker the ability to inject code or replace the MinecraftLauncher 
executable and have it run in the context of the system.
 
PoC:
 
C:\Program Files (x86)\Minecraft>icacls MinecraftLauncher.exe
MinecraftLauncher.exe BUILTIN\Users:(I)(F)
                      NT AUTHORITY\SYSTEM:(I)(F)
                      BUILTIN\Administrators:(I)(F)
                      PENTEST\ross.marks:(I)(F)
                      APPLICATION PACKAGE AUTHORITY\ALL APPLICATION PACKAGES:(I)(RX)
                      APPLICATION PACKAGE AUTHORITY\ALL RESTRICTED APP PACKAGES:(I)(RX)

Successfully processed 1 files; Failed processing 0 files