The OTA firmware update mechanism in Netun Solutions HelpFlash IoT (firmware v18_178_221102_ASCII_PRO_1R5_50) uses hard-coded WiFi credentials identical across all devices and does not authenticate update servers or validate firmware signatures. An attacker with brief physical access can activate OTA mode (8-second button press), create a malicious WiFi AP using the known credentials, and serve malicious firmware via unauthenticated HTTP to achieve arbitrary code execution on this safety-critical emergency signaling device.