How should vehicle manufacturers balance right to repair with cybersecurity controls in connected vehicles?

Preserving repair access without turning it into an attack path

connected vehicle need repairability, but repair access should be designed around the minimum capability required for diagnostics, calibration, and maintenance. The practical goal is to separate legitimate service functions from broader software trust, so that repair workflows do not become a route to code injection, unauthorized reprogramming, or unsafe configuration changes.

That usually means limiting what the repair surface can do, rather than trying to block repair entirely. A manufacturer can preserve access to fault codes, service telemetry, and authorized diagnostics while still requiring signed firmware, controlled tooling, and validated update channels for anything that changes vehicle behavior.

Repairability also becomes safer when the software supply path is treated as part of the vehicle security boundary. If a workshop or owner can fetch diagnostic utilities, ECU images, or calibration files from untrusted sources, the repair process can be subverted before the vehicle is even serviced. Manufacturer-controlled provenance is therefore as important as access itself.

Where the security boundary should sit

The cleanest boundary is usually between read-only support and state-changing actions. Reading diagnostics, viewing logs, and checking component health are lower risk than reflashing controllers, resetting safety logic, or pairing new modules. A good design allows the former broadly and constrains the latter with strong authentication, authorization, and integrity checks.

This is where software provenance matters most. Repair tools should verify signatures, firmware should be authenticated, and update packages should fail closed if integrity cannot be proven. The same logic applies to calibration data, because a seemingly minor configuration change can affect braking, steering assist, emissions behaviour, or battery management.

Manufacturers also need to think about privilege scope across the repair ecosystem. A technician, dealer, aftermarket shop, and independent owner may all need different levels of access, and those levels should not be interchangeable. The safest pattern is role- and task-based access that grants the narrowest practical function for the shortest practical time.

For connected vehicles, secure-by-design guidance such as CISA Secure by Design is a useful reference point because it reinforces default-safe product decisions, while ISO/IEC 27002:2022 Information Security Controls supports the control discipline behind access restriction, change control, and cryptographic protection.

Right to repair works best when trust is layered

Right to repair does not require unrestricted trust in every person or tool that touches the vehicle. The better model is layered trust: authenticated tools, signed artifacts, scoped permissions, auditability, and the ability to revoke access when a tool or supplier proves unsafe. That approach preserves repair economics without assuming every maintenance path is benign.

Connected vehicles also need lifecycle controls, because repair access today can become an abuse path tomorrow if credentials, certificates, or service tooling are reused indefinitely. Long-lived access tokens, shared vendor accounts, and undocumented bypass paths create the same sort of exposure in vehicles that they do in other cyber-physical systems: they outlive the original repair use case and widen the blast radius of compromise.

Good governance therefore treats repair access as something to inventory, review, and retire. The manufacturer should know which tools can authenticate, which firmware images can be installed, which modules can be reprogrammed, and which third parties can delegate service capability. If any of those elements cannot be explained and verified, the repair programme is carrying hidden security debt.

That lifecycle perspective aligns well with the control intent in NIST SP 800-53 Rev 5 Security and Privacy Controls, especially where access control, authentication, audit, and configuration management intersect, and with CIS Controls v8 for account management, secure configuration, and vulnerability management discipline.

Risk and Threat Considerations

Connected-vehicle repair surfaces are attractive to attackers because they combine physical access, software update paths, and high-trust maintenance assumptions. If a malicious actor can impersonate a technician, replace a tool, or tamper with a firmware package, the repair channel can become a way to persist inside the vehicle or influence safety-critical behaviour.

Failure mechanism: The control breaks when repair access is broader than the task, or when software and tooling provenance is not enforced. In that case, attackers can abuse diagnostic channels, malicious updates, or stolen service credentials to move from maintenance access to unauthorized code execution or unsafe reconfiguration.

Impact: The result can be vehicle compromise, degraded safety functions, customer data exposure, or large-scale abuse if a common repair toolchain is reused across many models or service networks.

Practitioner Guidance

What to prioritise: Protect the update and reflashing path first. If a repair action can change firmware or safety behaviour, require signed artifacts, explicit authorization, and revocation-capable access before expanding convenience features.

What to verify: Confirm that independent repair paths cannot bypass software provenance checks, that service tools authenticate to the vehicle in a controlled way, and that logging is sufficient to attribute who performed the change, when, and with what toolchain.

Common mistake: Treating the right-to-repair requirement as a binary open-or-closed decision. The better decision is to separate diagnostic openness from write-level control, then measure whether each repair action can be justified by its security impact.

Practitioner takeaway: The right balance is not “more access” or “more lock-down”, it is a repair model where legitimate maintenance stays usable while every code-changing path remains provable, revocable, and tightly bounded.

Related resources from NHI Mgmt Group

• How should manufacturers prioritize cybersecurity controls as smart factories become more connected?
• Why do connected vehicle cybersecurity controls need to be tied to regulatory requirements from the start?
• How should manufacturers govern cybersecurity across the full lifecycle of connected vehicles and industrial devices?
• How should security teams adapt IT cybersecurity controls for connected vehicles and fleets?