Your License Plate is a Remote Key: The 2024 Kia API Hack Case Study

[Note: This Write-up has been written under guidance of Rey Patel, Amish Patel, Hacker4help]

Introduction

Modern vehicles are no longer just mechanical machines; they are highly connected smart devices. Today’s cars are seamlessly controlled by smartphones and complex software ecosystems. However, these advanced features bring unprecedented cybersecurity risks — especially if the backend web servers powering them are not properly secured.

In 2024, a team of security researchers led by Sam Curry publicly disclosed a critical vulnerability affecting millions of Kia vehicles. They demonstrated how an attacker could gain remote, unauthorized access to a vehicle and control its core features using only publicly available information and a severe flaw in the web application’s authorization process.

Through this exploit, an attacker could silently extract the owner’s personal data, including their name, phone number, email address, and VIN (Vehicle Identification Number). More alarmingly, this allowed the attacker to add themselves as an invisible secondary user on the victim’s vehicle — granting them full access without the primary owner ever knowing.

To prove the severity of the flaw, the research team built a custom proof-of-concept tool. By simply entering a vehicle’s license plate number into this tool, an attacker could gain full remote access to the car in just 30 seconds. Fortunately, this tool was never officially published or used for malicious activity, but it served as a massive wake-up call for the automotive industry.

Vulnerability Overview

Kia relies on cloud infrastructure for smart features like remote unlock and engine start. However, this system had a critical weak link: the Kia Dealer Portal.

The portal’s registration page was loosely secured, allowing anyone to create a rogue “dealer” account and access highly privileged backend APIs. With this elevated access, an attacker only needed a vehicle’s VIN (easily found via a license plate lookup) to completely hijack the car.

The Attack Chain

(Reference the sequence diagram below for the technical flow)

Here is the fast breakdown of how the exploit worked:

1. Generate Token: The attacker registers a fake dealer account to receive a privileged API access token.
2. Extract Data: Using the target’s VIN, the attacker queries the backend to silently pull the legitimate owner’s email and phone number.
3. Hijack Ownership: The API allows the attacker to demote the real owner and assign themselves as the Primary Owner.
4. Total Control: Authenticated as the new owner, the attacker can now execute any remote command to the car.

Attack Chain Analysis: What Went Wrong?

This exploit wasn’t the result of a complex, sophisticated cyberweapon. Instead, it succeeded because of a chain of simple, overlooked web vulnerabilities:

• Broken Authentication: The dealer portal trusted anyone who hit the registration URL. It failed to verify if the person creating an account was an actual, authorized Kia dealer.
• Broken Object Level Authorization (BOLA): Once inside, the API didn’t check permissions. It allowed a brand-new “dealer” token to modify any VIN in the global database without verifying if that dealer actually owned or managed that specific car.
• Mass Assignment Vulnerability: The backend allowed sensitive account variables (like the primary owner’s email and phone number) to be overwritten through a standard API request without requiring multi-factor authentication (MFA) or owner approval.

Security Impact

While this vulnerability did not compromise safety-critical systems like steering or braking, it completely exposed the vehicle’s cloud-connected features. Once an attacker was registered as the primary owner, they could silently track the car’s real-time location, unlock the doors, and execute any supported Kia Connect function.

This case proves that a modern vehicle is only as secure as its backend APIs. To enhance security and prevent similar authorization flaws, companies are strongly advised to implement the Principle of Least Privilege (PoLP) across their cloud infrastructure. By ensuring that every user, token, and system process is granted only the absolute minimum access required to perform its specific task, organizations can effectively contain threats and safeguard user privacy from cloud-based attacks.

Conclusion

Fortunately, this story has a safe ending. The research team responsibly disclosed the flaw, and Kia fully patched the system by August 2024 before any real-world attacks occurred.

However, this incident is a massive wake-up call for the entire automotive industry. Today’s cars are essentially data centers on wheels. When a simple web API flaw can turn a license plate into a master key, it proves that securing the cloud is no longer just an IT issue — it is a fundamental requirement for driver safety and privacy. Going forward, automakers must treat software security with the exact same rigor as physical crash testing.

References & Further Reading

• Sam Curry’s Official Technical Write-up: Hacking Kia: How a License Plate Gained Full Remote Control of Millions of Vehicles
• Kaspersky Embedded Systems Security Blog: Vulnerability in Kia Car Remote Control Systems Explained