lib/msf/core/exploit/remote/ftp.rb
# -*- coding: binary -*-
module Msf
###
#
# This module exposes methods that may be useful to exploits that deal with
# servers that speak the File Transfer Protocol (FTP).
#
###
module Exploit::Remote::Ftp
include Exploit::Remote::Tcp
#
# Creates an instance of an FTP exploit module.
#
def initialize(info = {})
super
# Register the options that all FTP exploits may make use of.
register_options(
[
Opt::RHOST,
Opt::RPORT(21),
OptString.new('FTPUSER', [ false, 'The username to authenticate as', 'anonymous'], fallbacks: ['USERNAME']),
OptString.new('FTPPASS', [ false, 'The password for the specified username', 'mozilla@example.com'], fallbacks: ['PASSWORD']),
], Msf::Exploit::Remote::Ftp)
register_advanced_options(
[
OptInt.new('FTPTimeout', [ true, 'The number of seconds to wait for a reply from an FTP command', 16]),
OptBool.new('FTPDEBUG', [ false, 'Whether or not to print verbose debug statements', false ]),
OptBool.new('PassiveMode', [ false, 'Set true for extended passive (EPSV) ftp mode.', false])
], Msf::Exploit::Remote::Ftp)
register_autofilter_ports([ 21, 2121])
register_autofilter_services(%W{ ftp })
@ftpbuff = ""
end
#
# This method establishes an FTP connection to host and port specified by
# the 'rhost' and 'rport' methods. After connecting, the banner
# message is read in and stored in the 'banner' attribute.
#
def connect(global = true, verbose = nil)
verbose ||= datastore['FTPDEBUG']
verbose ||= datastore['VERBOSE']
print_status("Connecting to FTP server #{rhost}:#{rport}...") if verbose
fd = super(global)
# Wait for a banner to arrive...
self.banner = recv_ftp_resp(fd)
print_status("Connected to target FTP server.") if verbose
# Return the file descriptor to the caller
fd
end
#
# This method handles establishing datasocket for data channel
#
def data_connect(mode = nil, nsock = self.sock)
pass_mode = datastore['PassiveMode']
if mode
res = send_cmd([ 'TYPE' , mode ], true, nsock)
return nil if not res =~ /^200/
end
# force datasocket to renegotiate
self.datasocket.shutdown if self.datasocket != nil
# Need to be able to do both extended and normal
# passive modes. normal passive mode is default
# details of EPSV are in RFC2428
# pass_mode = true is EPSV; false is PASV
if pass_mode
res = send_cmd(['EPSV'], true, nsock)
return nil if not res =~ /^229/
# 229 Entering Passive Mode (|||port|)
if res =~ /\(\|\|\|(\d+)\|\)/
# convert port to FTP syntax
datahost = "#{rhost}"
dataport = $1.to_i
self.datasocket = Rex::Socket::Tcp.create(
'PeerHost' => datahost,
'PeerPort' => dataport,
'Context' => { 'Msf' => framework, 'MsfExploit' => self }
)
end
else
res = send_cmd(['PASV'], true, nsock)
return nil if not res =~ /^227/
# 227 Entering Passive Mode (127,0,0,1,196,5)
if res =~ /\((\d+)\,(\d+),(\d+),(\d+),(\d+),(\d+)/
# convert port to FTP syntax
datahost = "#{$1}.#{$2}.#{$3}.#{$4}"
dataport = ($5.to_i * 256) + $6.to_i
self.datasocket = Rex::Socket::Tcp.create(
'PeerHost' => datahost,
'PeerPort' => dataport,
'Context' => { 'Msf' => framework, 'MsfExploit' => self }
)
end
end
self.datasocket
end
#
# This method handles disconnecting our data channel
#
def data_disconnect
begin
if datasocket
datasocket.shutdown
datasocket.close
end
rescue IOError
end
datasocket = nil if datasocket
end
#
# Connect and login to the remote FTP server using the credentials
# that have been supplied in the exploit options.
#
def connect_login(global = true, verbose = nil)
verbose ||= datastore['FTPDEBUG']
verbose ||= datastore['VERBOSE']
ftpsock = ftp_connect(global, verbose)
if !(user and pass)
print_error("No username and password were supplied, unable to login")
return false
end
print_status("Authenticating as #{user} with password #{pass}...") if verbose
res = send_user(user, ftpsock)
if (res !~ /^(331|2)/)
print_error("The server rejected our username") if verbose
return false
end
if (pass)
print_status("Sending password...") if verbose
res = send_pass(pass, ftpsock)
if (res !~ /^2/)
print_error("The server rejected our password") if verbose
return false
end
end
return true
end
#
# This method logs in as the supplied user by transmitting the FTP
# 'USER <user>' command.
#
def send_user(user, nsock = self.sock)
raw_send("USER #{user}\r\n", nsock)
recv_ftp_resp(nsock)
end
#
# This method completes user authentication by sending the supplied
# password using the FTP 'PASS <pass>' command.
#
def send_pass(pass, nsock = self.sock)
raw_send("PASS #{pass}\r\n", nsock)
recv_ftp_resp(nsock)
end
#
# This method sends a QUIT command.
#
def send_quit(nsock = self.sock)
raw_send("QUIT\r\n", nsock)
recv_ftp_resp(nsock)
end
#
# This method sends one command with zero or more parameters
#
def send_cmd(args, recv = true, nsock = self.sock)
cmd = args.join(" ") + "\r\n"
ret = raw_send(cmd, nsock)
if (recv)
return recv_ftp_resp(nsock)
end
return ret
end
#
# This method transmits the command in args and receives / uploads DATA via data channel
# For commands not needing data, it will fall through to the original send_cmd
#
# For commands that send data only, the return will be the server response.
# For commands returning both data and a server response, an array will be returned.
#
# NOTE: This function always waits for a response from the server.
#
def send_cmd_data(args, data, mode = 'a', nsock = self.sock)
type = nil
# implement some aliases for various commands
if (args[0] =~ /^DIR$/i || args[0] =~ /^LS$/i)
# TODO || args[0] =~ /^MDIR$/i || args[0] =~ /^MLS$/i
args[0] = "LIST"
type = "get"
elsif (args[0] =~ /^GET$/i)
args[0] = "RETR"
type = "get"
elsif (args[0] =~ /^PUT$/i)
args[0] = "STOR"
type = "put"
end
# fall back if it's not a supported data command
if not type
return send_cmd(args, true, nsock)
end
# Set the transfer mode and connect to the remove server
return nil if not data_connect(mode)
# Our pending command should have got a connection now.
res = send_cmd(args, true, nsock)
# make sure could open port
return nil unless res =~ /^(150|125) /
# dispatch to the proper method
if (type == "get")
# failed listings just disconnect..
begin
data = datasocket.get(ftp_timeout, ftp_data_timeout)
rescue ::EOFError
data = nil
end
else
sent = self.datasocket.put(data)
end
# close data channel so command channel updates
data_disconnect
# get status of transfer
ret = nil
if (type == "get")
ret = recv_ftp_resp(nsock)
ret = [ ret, data ]
else
ret = recv_ftp_resp(nsock)
end
ret
end
#
# This method transmits a FTP command and waits for a response. If one is
# received, it is returned to the caller.
#
def raw_send_recv(cmd, nsock = self.sock)
nsock.put(cmd)
nsock.get_once(-1, ftp_timeout)
end
#
# This method reads an FTP response based on FTP continuation stuff
#
def recv_ftp_resp(nsock = self.sock)
found_end = false
resp = ""
left = ""
if !@ftpbuff.empty?
left << @ftpbuff
@ftpbuff = ""
end
while true
data = nsock.get_once(-1, ftp_timeout)
if not data
@ftpbuff << resp
@ftpbuff << left
return data
end
got = left + data
left = ""
# handle the end w/o newline case
enlidx = got.rindex(0x0a.chr)
if enlidx != (got.length-1)
if not enlidx
left << got
next
else
left << got.slice!((enlidx+1)..got.length)
end
end
# split into lines
rarr = got.split(/\r?\n/)
rarr.each do |ln|
if not found_end
resp << ln
resp << "\r\n"
if ln.length > 3 and ln[3,1] == ' '
found_end = true
end
else
left << ln
left << "\r\n"
end
end
if found_end
@ftpbuff << left
print_status("FTP recv: #{resp.inspect}") if datastore['FTPDEBUG']
return resp
end
end
end
#
# This method transmits a FTP command and does not wait for a response
#
def raw_send(cmd, nsock = self.sock)
print_status("FTP send: #{cmd.inspect}") if datastore['FTPDEBUG']
nsock.put(cmd)
end
##
#
# Wrappers for getters
#
##
#
# Returns the user string from the 'FTPUSER' option.
#
def user
datastore['FTPUSER']
end
#
# Returns the user string from the 'FTPPASS' option.
#
def pass
datastore['FTPPASS']
end
#
# Returns the number of seconds to wait for a FTP reply
#
def ftp_timeout
(datastore['FTPTimeout'] || 10).to_i
end
#
# Returns the number of seconds to wait to get more FTP data
#
def ftp_data_timeout
(datastore['FTPDataTimeout'] || 1).to_i
end
alias ftp_connect connect
protected
#
# This attribute holds the banner that was read in after a successful call
# to connect or connect_login.
#
attr_accessor :banner, :datasocket
end
end