##
# 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::Auxiliary
	include Msf::Exploit::Remote::HttpClient
	include Msf::Auxiliary::Scanner

	def initialize(info = {})
		super(update_info(info,
			'Name' => 'Wordpress Pingback Locator',
			'Description' => %q{
					This module will scan for wordpress sites with the Pingback
					API enabled. By interfacing with the API an attacker can cause
					the wordpress site to port scan an external target and return
					results. Refer to the wordpress_pingback_portscanner module.
				},
			'Author' =>
				[
					'Thomas McCarthy "smilingraccoon" <smilingraccoon[at]gmail.com>',
					'Brandon McCann "zeknox" <bmccann[at]accuvant.com>' ,
					'Christian Mehlmauer "FireFart" <FireFart[at]gmail.com>' # Original PoC
				],
			'License' => MSF_LICENSE,
			'References'  =>
				[
					[ 'URL', 'http://www.securityfocus.com/archive/1/525045/30/30/threaded'],
					[ 'URL', 'http://www.ethicalhack3r.co.uk/security/introduction-to-the-wordpress-xml-rpc-api/'],
					[ 'URL', 'https://github.com/FireFart/WordpressPingbackPortScanner']
				]
			))

			register_options(
				[
					OptString.new('TARGETURI', [ true, 'The path to wordpress installation (e.g. /wordpress/)', '/'])
				], self.class)

			register_advanced_options(
				[
					OptInt.new('NUM_REDIRECTS', [ true, "Number of HTTP redirects to follow", 10])
				], self.class)
	end

	def setup()
		# Check if database is active
		if db()
			@db_active = true
		else
			@db_active = false
		end
	end

	def get_xml_rpc_url(ip)
		# code to find the xmlrpc url when passed in IP
		vprint_status("#{ip} - Enumerating XML-RPC URI...")

		begin

			uri = target_uri.path
			uri << '/' if uri[-1,1] != '/'

			res = send_request_cgi(
			{
					'method'	=> 'HEAD',
					'uri'		=> "#{uri}"
			})
			# Check if X-Pingback exists and return value
			if res
				if res['X-Pingback']
					return res['X-Pingback']
				else
					vprint_status("#{ip} - X-Pingback header not found")
					return nil
				end
			else
				return nil
			end
		rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
			vprint_error("#{ip} - Unable to connect")
			return nil
		rescue ::Timeout::Error, ::Errno::EPIPE
			vprint_error("#{ip} - Unable to connect")
			return nil
		end
	end

	# Creates the XML data to be sent
	def generate_pingback_xml(target, valid_blog_post)
		xml = "<?xml version=\"1.0\" encoding=\"iso-8859-1\"?>"
		xml << "<methodCall>"
		xml << "<methodName>pingback.ping</methodName>"
		xml << "<params>"
		xml << "<param><value><string>#{target}</string></value></param>"
		xml << "<param><value><string>#{valid_blog_post}</string></value></param>"
		xml << "</params>"
		xml << "</methodCall>"
		return xml
	end

	def get_blog_posts(xml_rpc, ip)
		# find all blog posts within IP and determine if pingback is enabled
		vprint_status("#{ip} - Enumerating Blog posts on...")
		blog_posts = nil

		uri = target_uri.path
		uri << '/' if uri[-1,1] != '/'

		# make http request to feed url
		begin
			vprint_status("#{ip} - Resolving #{uri}?feed=rss2 to locate wordpress feed...")
			res = send_request_cgi({
				'uri'    => "#{uri}?feed=rss2",
				'method' => 'GET'
				})

			count = datastore['NUM_REDIRECTS']

			# Follow redirects
			while (res.code == 301 || res.code == 302) and res.headers['Location'] and count != 0
				vprint_status("#{ip} - Web server returned a #{res.code}...following to #{res.headers['Location']}")

				uri = res.headers['Location'].sub(/(http|https):\/\/.*?\//, "/")
				res = send_request_cgi({
					'uri'    => "#{uri}",
					'method' => 'GET'
					})

				if res.code == 200
					vprint_status("#{ip} - Feed located at #{uri}")
				else
					vprint_status("#{ip} - Returned a #{res.code}...")
				end
				count = count - 1
			end
		rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
			vprint_error("#{ip} - Unable to connect")
			return nil
		rescue ::Timeout::Error, ::Errno::EPIPE
			vprint_error("#{ip} - Unable to connect")
			return nil
		end

		if res.nil? or res.code != 200
			vprint_status("#{ip} - Did not recieve HTTP response from #{ip}")
			return blog_posts
		end

		# parse out links and place in array
		links = res.body.scan(/<link>([^<]+)<\/link>/i)

		if links.nil? or links.empty?
			vprint_status("#{ip} - Feed at #{ip} did not have any links present")
			return blog_posts
		end

		links.each do |link|
			blog_post = link[0]
			pingback_response = get_pingback_request(xml_rpc, 'http://127.0.0.1', blog_post)
			if pingback_response
				pingback_disabled_match = pingback_response.body.match(/<value><int>33<\/int><\/value>/i)
				if pingback_response.code == 200 and pingback_disabled_match.nil?
					print_good("#{ip} - Pingback enabled: #{link.join}")
					blog_posts = link.join
					return blog_posts
				else
					vprint_status("#{ip} - Pingback disabled: #{link.join}")
				end
			end
		end
		return blog_posts
	end

	# method to send xml-rpc requests
	def get_pingback_request(xml_rpc, target, blog_post)
		uri = xml_rpc.sub(/.*?#{target}/,"")
		# create xml pingback request
		pingback_xml = generate_pingback_xml(target, blog_post)

		# Send post request with crafted XML as data
		begin
			res = send_request_cgi({
				'uri'    => "#{uri}",
				'method' => 'POST',
				'data'	 => "#{pingback_xml}"
				})
		rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
			vprint_error("Unable to connect to #{uri}")
			return nil
		rescue ::Timeout::Error, ::Errno::EPIPE
			vprint_error("Unable to connect to #{uri}")
			return nil
		end
		return res
	end

	# Save data to vuln table
	def store_vuln(ip, blog)
		report_vuln(
			:host		=> ip,
			:proto		=> 'tcp',
			:port		=> datastore['RPORT'],
			:name		=> self.name,
			:info		=> "Module #{self.fullname} found pingback at #{blog}",
			:sname		=> datastore['SSL'] ? "https" : "http"
		)
	end

	# main control method
	def run_host(ip)
		# call method to get xmlrpc url
		xmlrpc = get_xml_rpc_url(ip)

		# once xmlrpc url is found, get_blog_posts
		if xmlrpc.nil?
			vprint_error("#{ip} - It doesn't appear to be vulnerable")
		else
			hash = get_blog_posts(xmlrpc, ip)

			if hash
				store_vuln(ip, hash) if @db_active
			else
				vprint_status("#{ip} - X-Pingback enabled but no vulnerable blogs found")
			end
		end
	end
end