254 lines
7.9 KiB
Ruby
254 lines
7.9 KiB
Ruby
# -*- coding: binary -*-
|
|
|
|
module Msf
|
|
|
|
require 'msf/core/exploit/tcp'
|
|
|
|
###
|
|
#
|
|
# This module exposes methods that may be useful to exploits that deal with
|
|
# servers that speak the telnet protocol.
|
|
#
|
|
###
|
|
module Exploit::Remote::Telnet
|
|
|
|
include Exploit::Remote::Tcp
|
|
include Auxiliary::Login
|
|
|
|
# Borrowing constants from Ruby's Net::Telnet class (ruby license)
|
|
IAC = 255.chr # "\377" # "\xff" # interpret as command
|
|
DONT = 254.chr # "\376" # "\xfe" # you are not to use option
|
|
DO = 253.chr # "\375" # "\xfd" # please, you use option
|
|
WONT = 252.chr # "\374" # "\xfc" # I won't use option
|
|
WILL = 251.chr # "\373" # "\xfb" # I will use option
|
|
SB = 250.chr # "\372" # "\xfa" # interpret as subnegotiation
|
|
GA = 249.chr # "\371" # "\xf9" # you may reverse the line
|
|
EL = 248.chr # "\370" # "\xf8" # erase the current line
|
|
EC = 247.chr # "\367" # "\xf7" # erase the current character
|
|
AYT = 246.chr # "\366" # "\xf6" # are you there
|
|
AO = 245.chr # "\365" # "\xf5" # abort output--but let prog finish
|
|
IP = 244.chr # "\364" # "\xf4" # interrupt process--permanently
|
|
BREAK = 243.chr # "\363" # "\xf3" # break
|
|
DM = 242.chr # "\362" # "\xf2" # data mark--for connect. cleaning
|
|
NOP = 241.chr # "\361" # "\xf1" # nop
|
|
SE = 240.chr # "\360" # "\xf0" # end sub negotiation
|
|
EOR = 239.chr # "\357" # "\xef" # end of record (transparent mode)
|
|
ABORT = 238.chr # "\356" # "\xee" # Abort process
|
|
SUSP = 237.chr # "\355" # "\xed" # Suspend process
|
|
EOF = 236.chr # "\354" # "\xec" # End of file
|
|
SYNCH = 242.chr # "\362" # "\xf2" # for telfunc calls
|
|
|
|
OPT_BINARY = 0.chr # "\000" # "\x00" # Binary Transmission
|
|
OPT_ECHO = 1.chr # "\001" # "\x01" # Echo
|
|
OPT_RCP = 2.chr # "\002" # "\x02" # Reconnection
|
|
OPT_SGA = 3.chr # "\003" # "\x03" # Suppress Go Ahead
|
|
OPT_NAMS = 4.chr # "\004" # "\x04" # Approx Message Size Negotiation
|
|
OPT_STATUS = 5.chr # "\005" # "\x05" # Status
|
|
OPT_TM = 6.chr # "\006" # "\x06" # Timing Mark
|
|
OPT_RCTE = 7.chr # "\a" # "\x07" # Remote Controlled Trans and Echo
|
|
OPT_NAOL = 8.chr # "\010" # "\x08" # Output Line Width
|
|
OPT_NAOP = 9.chr # "\t" # "\x09" # Output Page Size
|
|
OPT_NAOCRD = 10.chr # "\n" # "\x0a" # Output Carriage-Return Disposition
|
|
OPT_NAOHTS = 11.chr # "\v" # "\x0b" # Output Horizontal Tab Stops
|
|
OPT_NAOHTD = 12.chr # "\f" # "\x0c" # Output Horizontal Tab Disposition
|
|
OPT_NAOFFD = 13.chr # "\r" # "\x0d" # Output Formfeed Disposition
|
|
OPT_NAOVTS = 14.chr # "\016" # "\x0e" # Output Vertical Tabstops
|
|
OPT_NAOVTD = 15.chr # "\017" # "\x0f" # Output Vertical Tab Disposition
|
|
OPT_NAOLFD = 16.chr # "\020" # "\x10" # Output Linefeed Disposition
|
|
OPT_XASCII = 17.chr # "\021" # "\x11" # Extended ASCII
|
|
OPT_LOGOUT = 18.chr # "\022" # "\x12" # Logout
|
|
OPT_BM = 19.chr # "\023" # "\x13" # Byte Macro
|
|
OPT_DET = 20.chr # "\024" # "\x14" # Data Entry Terminal
|
|
OPT_SUPDUP = 21.chr # "\025" # "\x15" # SUPDUP
|
|
OPT_SUPDUPOUTPUT = 22.chr # "\026" # "\x16" # SUPDUP Output
|
|
OPT_SNDLOC = 23.chr # "\027" # "\x17" # Send Location
|
|
OPT_TTYPE = 24.chr # "\030" # "\x18" # Terminal Type
|
|
OPT_EOR = 25.chr # "\031" # "\x19" # End of Record
|
|
OPT_TUID = 26.chr # "\032" # "\x1a" # TACACS User Identification
|
|
OPT_OUTMRK = 27.chr # "\e" # "\x1b" # Output Marking
|
|
OPT_TTYLOC = 28.chr # "\034" # "\x1c" # Terminal Location Number
|
|
OPT_3270REGIME = 29.chr # "\035" # "\x1d" # Telnet 3270 Regime
|
|
OPT_X3PAD = 30.chr # "\036" # "\x1e" # X.3 PAD
|
|
OPT_NAWS = 31.chr # "\037" # "\x1f" # Negotiate About Window Size
|
|
OPT_TSPEED = 32.chr # " " # "\x20" # Terminal Speed
|
|
OPT_LFLOW = 33.chr # "!" # "\x21" # Remote Flow Control
|
|
OPT_LINEMODE = 34.chr # "\"" # "\x22" # Linemode
|
|
OPT_XDISPLOC = 35.chr # "#" # "\x23" # X Display Location
|
|
OPT_OLD_ENVIRON = 36.chr # "$" # "\x24" # Environment Option
|
|
OPT_AUTHENTICATION = 37.chr # "%" # "\x25" # Authentication Option
|
|
OPT_ENCRYPT = 38.chr # "&" # "\x26" # Encryption Option
|
|
OPT_NEW_ENVIRON = 39.chr # "'" # "\x27" # New Environment Option
|
|
OPT_EXOPL = 255.chr # "\377" # "\xff" # Extended-Options-List
|
|
|
|
|
|
#
|
|
# Creates an instance of a Telnet exploit module.
|
|
#
|
|
def initialize(info = {})
|
|
super
|
|
|
|
# Register the options that all Telnet exploits may make use of.
|
|
register_options(
|
|
[
|
|
Opt::RHOST,
|
|
Opt::RPORT(23),
|
|
OptString.new('USERNAME', [ false, 'The username to authenticate as' ]),
|
|
OptString.new('PASSWORD', [ false, 'The password for the specified username' ])
|
|
], Msf::Exploit::Remote::Telnet)
|
|
|
|
register_advanced_options(
|
|
[
|
|
OptInt.new('TelnetTimeout', [ true, 'The number of seconds to wait for a reply from a Telnet command', 10]),
|
|
OptInt.new('TelnetBannerTimeout', [ true, 'The number of seconds to wait for the initial banner', 25])
|
|
], Msf::Exploit::Remote::Telnet)
|
|
|
|
register_autofilter_ports([ 23 ])
|
|
register_autofilter_services(%W{ telnet })
|
|
end
|
|
|
|
#
|
|
# This method establishes an Telnet connection to host and port specified by
|
|
# the RHOST and RPORT options, respectively. After connecting, the banner
|
|
# message is read in and stored in the 'banner' attribute. This method has the
|
|
# benefit of handling telnet option negotiation.
|
|
#
|
|
def connect(global = true, verbose = true)
|
|
@trace = ''
|
|
@recvd = ''
|
|
fd = super(global)
|
|
banner_timeout = (datastore['TelnetBannerTimeout'] || 25).to_i
|
|
|
|
self.banner = ''
|
|
# Wait for a banner to arrive...
|
|
begin
|
|
Timeout.timeout(banner_timeout) do
|
|
while(true)
|
|
buff = recv(fd)
|
|
self.banner << buff if buff
|
|
if(self.banner =~ @login_regex or self.banner =~ @password_regex)
|
|
break
|
|
elsif self.banner =~ @busy_regex
|
|
# It's about to drop connection anyway -- seen on HP JetDirect telnet server
|
|
break
|
|
end
|
|
end
|
|
end
|
|
rescue ::Timeout::Error
|
|
end
|
|
|
|
self.banner.strip!
|
|
|
|
# Return the file descriptor to the caller
|
|
fd
|
|
end
|
|
|
|
|
|
def recv(fd=self.sock, timeout=datastore['TelnetTimeout'])
|
|
recv_telnet(fd, timeout.to_f)
|
|
end
|
|
|
|
#
|
|
# Handle telnet option negotiation
|
|
#
|
|
# Appends to the @recvd buffer which is used to tell us whether we're at a
|
|
# login prompt, a password prompt, or a working shell.
|
|
#
|
|
def recv_telnet(fd, timeout)
|
|
|
|
data = ''
|
|
|
|
begin
|
|
data = fd.get_once(-1, timeout)
|
|
return nil if not data or data.length == 0
|
|
|
|
# combine CR+NULL into CR
|
|
data.gsub!(/#{CR}#{NULL}/no, CR)
|
|
|
|
# combine EOL into "\n"
|
|
data.gsub!(/#{EOL}/no, "\n")
|
|
|
|
data.gsub!(/#{IAC}(
|
|
[#{IAC}#{AO}#{AYT}#{DM}#{IP}#{NOP}]|[#{DO}#{DONT}#{WILL}#{WONT}]
|
|
[#{OPT_BINARY}-#{OPT_NEW_ENVIRON}#{OPT_EXOPL}]|#{SB}[^#{IAC}]*#{IAC}#{SE}
|
|
)/xno) do
|
|
m = $1
|
|
|
|
if m == IAC
|
|
IAC
|
|
elsif m == AYT
|
|
fd.write("YES" + EOL)
|
|
''
|
|
elsif m[0,1] == DO
|
|
if(m[1,1] == OPT_BINARY)
|
|
fd.write(IAC + WILL + OPT_BINARY)
|
|
else
|
|
fd.write(IAC + WONT + m[1,1])
|
|
end
|
|
''
|
|
elsif m[0,1] == DONT
|
|
fd.write(IAC + WONT + m[1,1])
|
|
''
|
|
elsif m[0,1] == WILL
|
|
if m[1,1] == OPT_BINARY
|
|
fd.write(IAC + DO + OPT_BINARY)
|
|
# Disable Echo
|
|
elsif m[1,1] == OPT_ECHO
|
|
fd.write(IAC + DONT + OPT_ECHO)
|
|
elsif m[1,1] == OPT_SGA
|
|
fd.write(IAC + DO + OPT_SGA)
|
|
else
|
|
fd.write(IAC + DONT + m[1,1])
|
|
end
|
|
''
|
|
elsif m[0,1] == WONT
|
|
fd.write(IAC + DONT + m[1,1])
|
|
''
|
|
else
|
|
''
|
|
end
|
|
end
|
|
|
|
@trace << data
|
|
@recvd << data
|
|
fd.flush
|
|
|
|
rescue ::EOFError, ::Errno::EPIPE
|
|
end
|
|
|
|
data
|
|
end
|
|
|
|
def user
|
|
datastore["USERNAME"]
|
|
end
|
|
|
|
def pass
|
|
datastore["PASSWORD"]
|
|
end
|
|
|
|
##
|
|
#
|
|
# Wrappers for getters
|
|
#
|
|
##
|
|
|
|
#
|
|
# Returns the number of seconds to wait for a telnet reply
|
|
#
|
|
def tel_timeout
|
|
(datastore['TelnetTimeout'] || 10).to_i
|
|
end
|
|
|
|
protected
|
|
|
|
#
|
|
# This attribute holds the banner that was read in after a successful call
|
|
# to connect or connect_login.
|
|
#
|
|
attr_accessor :banner
|
|
|
|
end
|
|
|
|
end
|
|
|