Hardcoded credentials create the same access pattern across many devices, which means one leak or one reverse-engineered secret can expose repeated functions across a fleet. If those credentials also unlock updates or maintenance actions, the risk compounds. The result is identity debt built into firmware, with very limited room for containment once the secret is known.
Why hardcoded credentials become a fleet-wide problem
Hardcoded credentials are dangerous in connected products because they create a shared access path that repeats across devices, builds, and model years. In EV charging and infotainment, that can mean one exposed secret grants the same level of access everywhere it was embedded, turning a single compromise into a fleet issue rather than an isolated device problem.
That risk is not only about confidentiality. If the credential also authorises maintenance, updates, telemetry, or administrative functions, it can become an entry point for control-plane abuse. A secret that lives in firmware is difficult to revoke cleanly, so the exposure tends to persist long after the original leak.
Why EV charging and infotainment are especially sensitive
These systems sit close to functions that operators expect to be reliable, persistent, and remotely manageable. EV charging components often need service access, vendor support, firmware updates, and integration with back-end platforms; infotainment systems often maintain account links, paired devices, cloud services, and diagnostic channels. When one hardcoded credential bridges those functions, the blast radius can span multiple trust boundaries.
That matters because these environments are usually deployed at scale and updated unevenly. A credential embedded in firmware, a shared service image, or a vendor diagnostic path can outlive individual owners, survive device resale, and remain present across fielded units even after the original engineering team has moved on.
Why this weakens containment, recovery, and trust
Once a hardcoded secret is discovered, defenders usually cannot treat each affected device as independently compromised. The same value may be present in every unit, every region, or every supplier build that reused the same codebase. That makes containment slower, because the real question is not just whether one device is compromised, but how broadly the same credential was copied and where it still unlocks access.
It also weakens recovery. Rotating the secret may require firmware changes, dealer intervention, backend coordination, or a compatibility window for older devices. If the credential was used for remote management or update signing, the recovery effort can become a product lifecycle issue rather than a routine credential reset.
Risk and Threat Considerations
Hardcoded credentials create a predictable attack surface because they are the same across many deployments and are often recoverable through reverse engineering, exposed images, or leaked source artifacts. In connected vehicle and charging environments, that predictability can let one disclosure scale into repeated unauthorised access, privileged maintenance abuse, or persistent fleet-wide exposure.
Failure mechanism: A fixed secret is copied into firmware or software images, then reused by many devices and service paths, so one leak, one extracted binary, or one shared vendor account reveals a reusable access path across the fleet.
Impact: Attackers can reuse the same credential to reach repeated functions, expand access beyond a single device, and undermine the organisation's ability to contain or selectively revoke access.
Standards & Framework Alignment
This section maps relevant standards and security frameworks to the operational risks and controls described in this guidance.
OWASP Non-Human Identity Top 10 addresses the attack and risk surface, while NIST SP 800-53 Rev 5 sets the governance and control requirements practitioners need to meet.
| Framework | Control / Reference | Relevance |
|---|---|---|
| OWASP Non-Human Identity Top 10 | NHI-02 — Secret Leakage | Hardcoded credentials are leaked secrets that enable repeated access across devices. |
| NHI-07 — Long-Lived Secrets | Static firmware credentials persist far longer than the access they should grant. | |
| NHI-05 — Overprivileged NHI | Hardcoded credentials often unlock more access than the device or service needs. | |
| Recommendation — Eliminate embedded secrets and rotate any exposed credentials immediately. Replace long-lived secrets with short-lived, revocable credentials. Reduce privilege to the minimum required for each device function. | ||
| NIST SP 800-53 Rev 5 | IA-5 — Authenticator Management | The issue is credential lifecycle, rotation, and revocation across a fleet. |
| IA-9 — Service Identification and Authentication | EV charging and infotainment often use machine-to-machine authentication that must not rely on shared static secrets. | |
| AC-6 — Least Privilege | If the credential is compromised, limiting its rights reduces fleet-wide impact. | |
| Recommendation — Manage authenticators so embedded credentials can be changed or revoked safely. Use distinct service authenticator controls instead of shared embedded secrets. Scope each credential to the minimum permissions needed for its function. | ||
Practitioner Guidance
What to verify: Determine whether the credential unlocks only low-risk telemetry or whether it reaches update, diagnostic, pairing, or administrative functions. If it can alter software, change configuration, or expose customer data, treat it as a high-impact secret and map every place it is embedded.
Decision rule: If a secret is compiled into firmware or distributed to many devices, plan for replacement by design rather than by incident response. If you cannot revoke it without breaking deployed units, you have a lifecycle problem that needs a migration path, not just a patch.
What practitioners underestimate: The hardest part is often not finding the secret, but proving where else it was reused. The same credential may exist in supplier tooling, service portals, mobile apps, test environments, and update infrastructure, so remediation needs inventory and ownership before rotation.
Practitioner takeaway: Hardcoded credentials become dangerous when they are reusable, difficult to revoke, and tied to privileged product functions. In EV charging and infotainment, the key judgement is whether the secret creates fleet-wide trust, because that determines the blast radius and the recovery path.
Related resources from NHI Mgmt Group
- Guide: Guide to the Secret Sprawl Challenge
- What is the main risk when automation systems store ServiceNow credentials?
- How should teams reduce the risk of exposed AI credentials being abused?
- Why do generative AI credentials increase the blast radius of a leak?
- Why do reusable credentials increase supply chain risk in build systems?
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Reviewed and updated by the NHIMG editorial team on October 22, 2026.
NHI Mgmt Group — the #1 independent authority on Non-Human Identity, IAM, and Agentic AI security. nhimg.org