True Attack Surface of a Modern Car

Where vehicles are most vulnerable?

When people think about automotive hacking, they often imagine a single dramatic moment: a hacker taking over a car from a laptop. Reality is less cinematic and far more structural.

The real attack surface of a modern vehicle is not one component, one ECU, or one wireless interface. It is an interconnected system spanning in-vehicle networks, telematics devices, cloud platforms, mobile apps, and third-party services.

Over the past decade, real-world incidents have shown – repeatedly -that attackers do not need full control of a vehicle to cause serious damage. They only need access to one weak layer.

1. In-Vehicle Networks: Designed for Trust, Not Defense

Modern vehicles rely on internal networks such as CAN, LIN, and increasingly Automotive Ethernet. These networks were designed for reliability and real-time performance—not security.

Jeep Cherokee Hack (2015): CAN as an Attack Vector

In 2015, security researchers Charlie Miller and Chris Valasek remotely compromised a Jeep Cherokee by exploiting the Uconnect infotainment system and pivoting into the CAN bus.
They were able to manipulate steering, brakes, and engine functions under controlled conditions.

Lesson:
 Once an attacker reaches the in-vehicle network, trust assumptions collapse quickly.

2. Telematics Layer: The Always-On Entry Point

Telematics systems—TCUs or OBD-based devices—are designed to be continuously connected. That makes them operationally valuable, but also persistent targets.

Nissan LEAF API Exposure (2016)

Researchers demonstrated that Nissan LEAF vehicles could be accessed remotely using only the VIN, allowing attackers to control climate systems and retrieve driving data.

  • BBC coverage:
    https://www.bbc.com/news/technology-35642749

While this did not affect driving controls, it showed how weak authentication in telematics APIs can expose vehicle functions and user data at scale.

Lesson:
 Telematics is not just a data pipe. It is part of the vehicle’s security perimeter.

3. Mobile Apps and Cloud APIs: The Fastest-Growing Risk Area

As vehicles become software-defined, control increasingly moves into cloud backends and mobile applications.

Tesla Third-Party App Vulnerabilities (2022)

Security researchers disclosed vulnerabilities in third-party Tesla apps that exposed access tokens, allowing attackers to unlock cars, access location data, and control certain features remotely.

  • TechCrunch coverage:
    https://techcrunch.com/2022/01/24/teslamate-bug-teslas-exposed-remote/

Tesla patched affected APIs, but the incident highlighted a growing issue: vehicle security now depends on software practices far beyond the vehicle itself.

Lesson:
 The attack surface extends to every API, SDK, and integration partner.

4. Keyless Entry and Short-Range Wireless Exploits

Not all attacks are remote. Some are simple, scalable, and highly effective.

Honda “Rolling-PWN” Replay Attack (2022)

Researchers demonstrated a replay attack that allowed unlocking Honda vehicles by capturing and replaying key fob signals.

  • KeySignt report:
    https://www.keysight.com/blogs/en/tech/nwvs/2022/08/29/security-highlight-rolling-pwn-automotive-attack
  • CVE reference:
    https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-46145

Although proximity was required, the attack was repeatable and automated.

Lesson:
 Short-range interfaces can still be mass-exploitable when cryptographic protections are weak.

5. Supply Chain and Backend Systems: The Invisible Exposure

Vehicles increasingly depend on suppliers, cloud platforms, and data services. Attacks on these systems often bypass vehicle defenses entirely.

Toyota Cloud Data Exposure (2023)

Toyota disclosed that misconfigured cloud systems exposed location and vehicle data for over 2 million customers for nearly a decade.

  • Reuters coverage:
    https://www.reuters.com/business/autos-transportation/toyota-flags-possible-leak-more-than-2-mln-users-vehicle-data-japan-2023-05-12/

This was not a vehicle-level exploit, but its impact was widespread.

Lesson:
 A vehicle’s security is only as strong as the weakest cloud or supplier configuration.

6. Physical Access Still Matters

Despite advances in connectivity, physical access remains a major vector—especially in regions with mixed fleet ages.

Kia and Hyundai Theft Crisis (2021–2023)

Certain Kia and Hyundai models lacked electronic immobilizers, allowing theft using basic tools. The issue became widespread after social media demonstrations.

  • Associated Press report:
    https://apnews.com/article/hyundai-kia-tiktok-theft-stolen-8e0a353d24be0e7bce36e34c5e4dac51

Insurers responded by raising premiums or refusing coverage in some cities.

Lesson:
 Cybersecurity and physical security failures often intersect—and scale rapidly.

7. What These Incidents Have in Common

Across very different attack types, several patterns emerge:

  1. Attackers target the easiest layer, not the most critical one
  2. Connectivity multiplies impact – a single flaw can affect millions of vehicles
  3. Security assumptions age poorly – systems designed without threat models become liabilities
  4. Vehicle security is no longer self-contained – it spans vehicles, cloud, apps, and partners

This is why modern regulations (such as UNR 155) emphasize continuous monitoring, not one-time certification.

8. Why Telematics Is Central to the Attack Surface

Telematics sits at the intersection of:

  • vehicle networks
  • cloud systems
  • mobile applications
  • operational analytics

That makes it both a high-value sensor and a high-risk gateway.

Well-designed telematics can:

  • detect abnormal behavior early
  • identify compromised components
  • support incident response

Poorly designed telematics can:

  • expose vehicle networks
  • leak sensitive data
  • amplify attacks across fleets

The difference is architectural, not cosmetic.

Conclusion

The true attack surface of a modern car is not defined by a single exploit. It is defined by how many systems are connected, how well they are monitored, and how quickly anomalies are detected.

Real incidents – from Jeep to Tesla to Toyota – have already answered the question of whether this matters.

The remaining question for the industry is simpler and harder:

Will vehicles be monitored and secured as continuously as the systems they now resemble?

That answer will define the next decade of connected mobility.

By x18 Editorial