Module: Msf::Exploit::Remote::FtpServer

Includes:
TcpServer
Defined in:
lib/msf/core/exploit/remote/ftp_server.rb

Overview

This module exposes methods that may be useful to exploits that deal with clients that speak the File Transfer Protocol (FTP).

Instance Attribute Summary

Attributes included from SocketServer

#service

Instance Method Summary collapse

Methods included from TcpServer

#ssl, #ssl_cert, #ssl_cipher, #ssl_compression, #ssl_version, #start_service

Methods included from SocketServer

#_determine_server_comm, #bindhost, #bindport, #cleanup, #cleanup_service, #exploit, #primer, #regenerate_payload, #srvhost, #srvport, #start_service, #via_string

Instance Method Details

#active_data_port_for_client(c, port) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 189

def active_data_port_for_client(c,port)
  @state[c][:mode] = :active

  connector = Proc.new {
    host = c.peerhost.dup
    sock = Rex::Socket::Tcp.create(
      'PeerHost' => host,
      'PeerPort' => port,
      'Context'   => { 'Msf' => framework, 'MsfExploit' => self }
    )
    add_socket(sock)
    sock
  }

  @state[c][:active_connector] = connector
  @state[c][:active_port]      = port
end

#establish_data_connection(c) ⇒ Socket?

Create a socket for the protocol data, either PASV or PORT, depending on the client.

Parameters:

  • c (Socket) —

    Control connection socket

Returns:

  • (Socket) —

    A connected socket for the data connection

  • (nil) —

    on failure

See Also:



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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 217

def establish_data_connection(c)
  begin
  Timeout.timeout(20) do
    if(@state[c][:mode] == :active)
      return @state[c][:active_connector].call()
    end
    if(@state[c][:mode] == :passive)
      c = @state[c][:passive_sock].accept
      add_socket(c)
      return c
    end
  end

  rescue ::Exception => e
    print_error("Failed to establish data connection: #{e.class} #{e}")
  end

  nil
end

#initialize(info = {}) ⇒ Object

Creates an instance of an FTP exploit module.



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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 18

def initialize(info = {})
  super

  # Register the options that all FTP exploits may make use of.
  register_options(
    [
      OptPort.new('SRVPORT',    [ true, "The local port to listen on.", 21 ]),
      OptPort.new('PASVPORT',   [ false, "The local PASV data port to listen on (0 is random)", 0 ])
    ], Msf::Exploit::Remote::FtpServer)
end

#on_client_close(c) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 165

def on_client_close(c)
  @state.delete(c)
end

#on_client_connect(c) ⇒ Object

Called when a client connects.



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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 36

def on_client_connect(c)
  @state[c] = {
    :name => "#{c.peerhost}:#{c.peerport}",
    :ip   => c.peerhost,
    :port => c.peerport,
    :user => nil,
    :pass => nil,
    :cwd  => '/'
  }

  active_data_port_for_client(c, 20)

  c.put "220 FTP Server Ready\r\n"
end

#on_client_data(c) ⇒ Object

Dispatches client requests to command handlers.

Handlers should be named on_client_command_*, ending with a downcased FTP verb, e.g. on_client_command_user. If no handler exists for the given command, returns a generic default response.

Examples:

Handle SYST requests

class MetasploitModule < Msf::Exploit
  include Msf::Exploit::Remote::FtpServer
  ...
  def on_client_command_syst(cmd_conn, arg)
    print_status("Responding to SYST request")
    buf = build_exploit_buffer(cmd_conn)
    cmd_conn.put("215 Unix Type: #{buf}\r\n")
  end
end


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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 70

def on_client_data(c)
  data = c.get_once
  return if not data

  cmd,arg = data.strip.split(/\s+/, 2)
  arg ||= ""

  return if not cmd

  # Allow per-command overrides
  if self.respond_to?("on_client_command_#{cmd.downcase}", true)
    return self.send("on_client_command_#{cmd.downcase}", c, arg)
  end

  case cmd.upcase
  when 'USER'
    @state[c][:user] = arg
    c.put "331 User name okay, need password...\r\n"
    return

  when 'PASS'
    @state[c][:pass] = arg
    print_status("#{@state[c][:name]} LOGIN #{@state[c][:user]} / #{@state[c][:pass]}")
    c.put "230 Login OK\r\n"
    return

  when 'QUIT'
    c.put "221 Logout\r\n"
    return

  when 'SYST'
    c.put "215 UNIX Type: L8\r\n"
    return

  when 'TYPE'
    c.put "200 Type is set\r\n"
    return

  when 'CWD'
    c.put "250 CWD command successful.\r\n"
    return

  when 'PWD'
    c.put "257 \"#{@state[c][:cwd]}\" is current directory.\r\n"
    return

  when 'SIZE'
    c.put "213 1\r\n"
    return

  when 'MDTM'
    c.put "213 #{Time.now.strftime("%Y%m%d%H%M%S")}\r\n"
    return

  when 'PORT'
    port = arg.split(',')[4,2]
    if(not port and port.length == 2)
      c.put("500 Illegal PORT command.\r\n")
      return
    end

    port = port.map{|x| x.to_i}.pack('C*').unpack('n')[0]
    active_data_port_for_client(c, port)

    c.put "200 PORT command successful.\r\n"
    return

  when 'PASV'
    daddr = Rex::Socket.source_address(c.peerhost)
    dport = passive_data_port_for_client(c)
    @state[c][:daddr] = daddr
    @state[c][:dport] = dport
    pasv  = (daddr.split('.') + [dport].pack('n').unpack('CC')).join(',')
    c.put "227 Entering Passive Mode (#{pasv})\r\n"
    return

  when /^(STOR|MKD|REM|DEL|RMD)$/
    c.put "500 Access denied\r\n"
    return

  else
    # Allow per-command overrides
    if(self.respond_to?("on_client_unknown_command"))
      return self.send("on_client_unknown_command", c, cmd.upcase, arg)
    end

    print_status("#{@state[c][:name]} UNKNOWN '#{cmd} #{arg}'")
    c.put("500 '#{cmd} #{arg}': command not understood.\r\n")
    return
  end

  return

end

#passive_data_port_for_client(c) ⇒ Object 



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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 169

def passive_data_port_for_client(c)
  @state[c][:mode] = :passive

  if(not @state[c][:passive_sock])
    s = Rex::Socket::TcpServer.create(
      'LocalHost' => '0.0.0.0',
      'LocalPort' => datastore['PASVPORT'].to_i,
      'Context'   => { 'Msf' => framework, 'MsfExploit' => self }
    )

    dport = s.getsockname[2]

    @state[c][:passive_sock] = s
    @state[c][:passive_port] = dport
    add_socket(s)
  end

  @state[c][:passive_port]
end

#setup ⇒ Object

Prepares the module for exploitation, initializes any state, and starts the payload handler.



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# File 'lib/msf/core/exploit/remote/ftp_server.rb', line 30

def setup
  super
  @state = {}
end