Why do IoT devices increase risk even when each device seems low value?

Why This Matters for Security Teams

IoT risk is rarely caused by a single “important” device. The real problem is fleet scale: every sensor, camera, controller, badge reader, or gateway becomes another trust path, another place where secrets can live, and another endpoint that may be reachable from internal systems. NIST’s NIST Cybersecurity Framework 2.0 treats asset visibility and access governance as core security outcomes for a reason. Once devices are deployed broadly, weak authentication, stale firmware, and inconsistent provisioning create cumulative exposure that is far larger than any single device suggests.

That pattern shows up repeatedly in NHI research as well. The Ultimate Guide to NHIs — Why NHI Security Matters Now notes that NHIs outnumber human identities by 25x to 50x in modern enterprises, and 97% carry excessive privileges. IoT fleets often inherit the same failure mode: many identities, poor rotation, and little visibility. In practice, many security teams encounter IoT risk only after a forgotten device or shared credential has already been used to move laterally across the environment, rather than through intentional fleet governance.

How It Works in Practice

IoT devices increase risk because they multiply the number of things that must be authenticated, updated, monitored, and eventually retired. A device may look low value on its own, but at fleet level it can become a durable foothold if it uses hard-coded secrets, default passwords, or over-permissive API access. The security model should therefore focus on identity, lifecycle, and communication paths, not just device cost or function.

Operationally, that means treating IoT as a non-human identity problem. The most useful controls are familiar: unique device identities, per-device secrets, short-lived credentials where possible, strong network segmentation, and disciplined offboarding. NHIMG research in the Top 10 NHI Issues highlights why this matters: only 5.7% of organisations report full visibility into service accounts, and 96% store secrets outside secrets managers in vulnerable locations. The same governance gaps appear in IoT when certificates are reused, keys are embedded in firmware, or field devices are never rotated.

• Inventory every device type, owner, firmware version, and credential source.
• Issue unique identities per device or per device class, never shared passwords.
• Use network allowlists and segmented zones so devices can reach only required services.
• Rotate secrets and certificates on a schedule, and revoke them on decommission.
• Monitor for anomalous device-to-service behavior, not just malware signatures.

Where vendors support it, align device identity with workload identity patterns and certificate-based trust, because that makes revocation and auditability much stronger than static shared credentials. These controls tend to break down when legacy IoT fleets cannot support unique identity, secure update channels, or certificate rotation because operational constraints force shared credentials and exceptions.

Common Variations and Edge Cases

Tighter device controls often increase operational overhead, requiring organisations to balance resilience against deployment speed, maintenance effort, and field reliability. That tradeoff is most visible in legacy environments, remote facilities, and safety-critical systems where patching windows are narrow and replacement cycles are long.

Current guidance suggests several variations need special handling. Consumer IoT is often easiest to over-trust because it looks harmless, but it may still provide a path into corporate Wi-Fi, SaaS integrations, or physical spaces. Industrial IoT may have stronger segmentation, yet weaker patchability and longer lifetimes, which makes revocation and firmware governance harder. In mixed environments, a low-value device can still matter if it reaches privileged management planes or acts as a bridge between zones. The Ultimate Guide to NHIs — Key Challenges and Risks emphasizes how often secrets are mismanaged and how frequently organisations lack offboarding discipline; those same weaknesses apply when devices are replaced, reassigned, or returned to stock.

Best practice is evolving around whether every IoT device must have a unique cryptographic identity or whether some classes can safely share a managed identity. There is no universal standard for this yet, but the direction is clear: organisations should minimize shared credentials, shorten credential lifetimes, and treat device retirement as a security event, not an inventory update.

Related resources from NHI Mgmt Group

• Why do open USB ports increase insider threat risk on managed devices?
• Why do machine credentials in repositories increase lateral movement risk?
• Why do public IP addresses create security risk even without a breach?
• Why does DNS spoofing create identity risk even when login controls are strong?