CVE-2025-40939

#!/bin/bash # CVE-2025-40939 PoC - SIMATIC CN 4100 USB DoS Trigger # Description: Physical access to USB port can trigger device reboot causing DoS # Note: This PoC simulates the attack concept for educational purposes only # Check if running on appropriate system with USB access if [ ! -d "/dev/bus/usb" ]; then echo "[-] USB bus not accessible" exit 1 fi # Target device identification TARGET_VENDOR="Siemens" TARGET_PRODUCT="SIMATIC CN 4100" # USB device enumeration USB_DEVICES=$(ls -la /dev/bus/usb/ 2>/dev/null) echo "[*] Enumerating USB devices..." echo "$USB_DEVICES" # Note: Actual exploitation requires physical access to the device # and specific knowledge of the USB protocol used by SIMATIC CN 4100 # Simulated attack sequence echo "[*] CVE-2025-40939 Attack Simulation" echo "[*] Target: $TARGET_PRODUCT" echo "[*] Attack Vector: Physical USB Access" echo "[*] Impact: Device Reboot -> Denial of Service" # Attack would involve: # 1. Physical connection to USB port # 2. Sending malicious USB commands to trigger reboot # 3. Device enters DoS state echo "[!] This is a simulated PoC for CVE-2025-40939" echo "[!] Physical access to target device is required" echo "[!] Use only in authorized testing environments"

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