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Critical Authentication Flaw Exposed in Major Automaker Dealer Portal

Security researcher Eaton Zveare discovered a critical flaw in a top carmaker’s dealership portal that allowed creation of a “national admin” account. Hackers could view private customer data, track vehicles, and hijack remote control features by bypassing login—simply by tweaking browser code. The flaw was fixed within a week, but this incident highlights systemic authentication gaps in dealer systems.

Published August 10, 2025 at 09:07 PM EDT in Cybersecurity

Uncovering the Dealer Portal Flaw

Over the past year, Eaton Zveare, a security researcher at Harness, exposed a serious vulnerability in a major carmaker’s online dealership portal. By exploiting a simple flaw in the login process, Zveare was able to create a “national admin” account that granted unfettered access to thousands of dealer profiles and centralized systems.

Bypassing Authentication Controls

The root cause lay in the portal’s front-end, where authentication checks were performed in browser-loaded code. With minimal tweaks in developer tools, Zveare bypassed the login mechanism entirely. This hack allowed him to infiltrate every dealer’s account without ever needing legitimate credentials.

  • Access to over 1,000 dealers’ private and financial data
  • Real-time vehicle tracking and telematics control
  • Remote pairing of mobile accounts for unlocking cars
  • Single sign-on across dealer systems with user impersonation

Real-World Impact

In a live demonstration, Zveare used a vehicle’s visible VIN from a public parking lot to retrieve the owner’s name, address, and financial details via the portal’s national consumer lookup. He also paired a friend’s car with his own mobile account—proof that a mere attestation was enough to hijack remote unlocking features.

Broader Industry Implications

The incident highlights a worrying trend: interconnected dealership systems and single sign-on features amplify risk. Similar flaws surfaced at Toyota in 2023. As dealer portals tie CRM, finance, and telematics together, a single exploit can cascade across multiple platforms and carriers.

Key Takeaways

  • Authentication flaws are a gateway to full system compromise
  • Front-end code and API endpoints need rigorous validation

How QuarkyByte Can Help

With QuarkyByte’s automotive cybersecurity expertise, organizations can conduct targeted penetration tests, simulate admin-level breaches, and fortify API authentication. Our proactive threat modeling and continuous monitoring help safeguard customer data and vehicle control features before attackers find the loopholes.

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