Zero-Trust Architecture for Automotive Diagnostic Interfaces: Preventing Malicious Dongle Exploitation

Abstract: Analyzing attack scenarios leveraging aftermarket telematics dongles and validating zero-trust gateway filtering mechanisms.

1. Aftermarket Dongle Vulnerabilities Millions of vehicles utilize aftermarket telematics dongles plugged into the OBD-II port for fleet management or insurance monitoring. Many dongles possess cellular modems with weak firmware security, providing remote attackers with an unmonitored gateway directly onto the vehicle's internal network.

2. Zero-Trust Gateway Validation By placing a secure gateway between the OBD-II connector and internal buses, diagnostic commands were restricted using strict rate limiting and service whitelisting. Even when the external dongle was fully compromised, attacks attempting to transmit steering torque overrides were blocked with zero safety impact.