What is IoT Cybersecurity?

Billions of IoT devices and operational technology systems are now woven into daily life. From smart speakers and wearables to industrial control systems that run power plants and factories, this connected world brings huge advantages—and serious security challenges.

For IT professionals, understanding IoT cybersecurity is no longer optional. Poorly secured IoT and OT environments expand the attack surface, expose sensitive data, and can even impact physical safety.

This guide updates CompTIA’s original content to explain what IoT cybersecurity is, why it matters, common vulnerabilities and threats, and practical strategies to protect IoT devices in both consumer and industrial environments.

IoT cybersecurity: How to protect connected devices and critical systems

IoT cybersecurity (sometimes written as IoT security or cyber security for IoT) is the practice of securing:

• Internet‑connected sensors and smart devices
• Industrial control systems (ICS) and operational technology (OT)
• The networks, systems, and cloud platforms that connect them

The goal is to protect the confidentiality, integrity, and availability of data, services, and physical processes against cyber threats, cyberattacks, and misuse.

Because IoT devices often sit at the edge of a network, outside traditional data centers, they’re exposed to unique risks:

• Limited processing power and memory
• Infrequent firmware updates
• Hard‑coded passwords or default credentials
• Insecure communications and management protocols

Effective IoT cybersecurity must account for these constraints while still delivering strong defense.

Why IoT cybersecurity matters

There are more than 24 billion active IoT and OT devices today, with billions more coming online. Each device is a potential entry point into your network and critical infrastructure.

For individuals

• Compromised smart home devices (cameras, door locks, baby monitors) can expose private spaces.
• Wearables and health sensors may leak sensitive medical information.
• Hijacked consumer devices can be conscripted into botnets that fuel global cyberattacks.

For businesses and organizations

• Industrial IoT devices can directly affect safety by controlling machinery, pipelines, or medical equipment.
• Attackers can compromise IoT gateways to pivot into enterprise systems and cloud workloads.
• A single incident can disrupt operations, violate compliance requirements, and damage brand trust.

Because of this, IoT cybersecurity is now a core part of any cybersecurity strategy, alongside traditional computers, servers, and mobile devices.

Understanding IoT, OT, and Industrial Control Systems

You’ll often see “IoT,” “OT” and “ICS” discussed together.

• IoT (Internet of Things) – Consumer and enterprise connected devices such as cameras, thermostats, wearables, smart TVs, and building systems.
• OT (Operational Technology) – Industrial hardware and systems that monitor or control physical processes (e.g., factory robots, turbines, water pumps).
• Industrial control systems (ICS) – The technology and networks that coordinate OT devices: SCADA systems, PLCs, sensors, and actuators.

When an IoT device can alter a physical process—such as opening a valve or changing voltage—it’s typically considered an OT device. OT security focuses on these industrial environments, where safety and uptime are paramount.

IoT cybersecurity must consider both sets of requirements: classic IT security and the unique needs of OT and ICS.

What makes IoT devices vulnerable?

Most IoT devices follow a similar pattern, whether they’re consumer gadgets or industrial sensors. Inside a typical unit, you’ll find:

• Firmware – Embedded code that controls the hardware and core security functions.
• Microcontroller – A small processor that runs the software.
• Connectivity stack – Modules and protocols providing Wi‑Fi, Bluetooth, Zigbee, cellular or other network access.
• Authentication services – Optional features for validating users and other devices.
• Memory and storage – For configuration, logs, and local data.
• Sensors – To capture motion, temperature, location, and other inputs.

Each element introduces potential vulnerabilities. Common weaknesses include:

• Inadequate default settings – Factory passwords that cannot be changed, overly permissive access controls.
• Non‑existent upgrade paths – No ability to patch firmware or software, leaving known flaws unaddressed.
• Inappropriate technology choices – Full operating systems where a lightweight stack would do, giving attackers more tools when the device is compromised.
• Insecure communications – Lack of encryption or authentication for network traffic.

These issues create risk not just for a single product but for entire networks of connected devices.

Best practices for IoT device security

To protect modern environments, IT and cybersecurity teams should implement layered IoT security controls across devices, networks, and systems.

1. Strengthen device identity and access

• Change default passwords immediately and use strong, unique credentials.
• Where possible, require multi‑factor authentication for administrative access.
• Use certificate‑based authentication for IoT devices connecting to cloud platforms.
• Disable unused accounts and services to reduce the attack surface.

2. Keep firmware and software updated

• Choose manufacturers and developers that offer a clear update policy and signed firmware releases.
• Automate updates where appropriate, especially for “headless” devices without user interfaces.
• Decommission or isolate devices that can no longer be patched—permanently vulnerable hardware is a long‑term risk.

3. Encrypt communications and data

• Use TLS or VPNs to protect data‑in‑transit between IoT devices, gateways, and cloud or on‑prem systems.
• Encrypt sensitive data at rest on the device and in the back‑end infrastructure.
• Ensure protocols and cipher suites meet current security best practices.

4. Segment networks and limit blast radius

• Separate IoT devices from core enterprise systems using VLANs, firewalls, or micro‑segmentation.
• Apply least‑privilege routing: only allow the communications each device truly needs.
• Use dedicated management networks for industrial control systems and OT environments.

5. Enhance monitoring, detection, and response

• Deploy IDS/IPS and behavioral monitoring tuned for IoT traffic patterns.
• Centralize logs in a SIEM to correlate events across systems, networks, and devices.
• Use threat‑intelligence feeds to stay ahead of emerging cyber threats targeting IoT devices.

These practices help ensure that even when a device is compromised, the network and critical systems remain resilient.

Addressing IoT security challenges

Securing IoT and OT is complex for several reasons.

Diverse devices and manufacturers

• Thousands of manufacturers ship connected devices with different software stacks and life‑cycle policies.
• Some prioritize time‑to‑market and cost over robust security and safeguards.

Mitigation:

• Include IoT security requirements in procurement processes and vendor contracts.
• Favor vendors that follow recognized protocols, standards, and NIST recommendations for IoT devices.
• Maintain an accurate inventory of all devices and their firmware status.

Limited processing power and resources

• Many IoT devices are resource‑constrained, making traditional security tools harder to deploy.

Mitigation:

• Offload heavy detection and analytics to gateways or cloud services.
• Use lightweight agents and protocols designed for constrained environments.
• Rely on strong network controls and defense‑in‑depth around fragile endpoints.

Blurred lines between IT and OT security

• Traditional IT security teams and OT engineers may have different priorities and vocabularies.
• OT uptime and safety concerns can make patching and maintenance more difficult.

Mitigation:

• Align IT and OT teams under a shared strategy that treats OT security as part of enterprise cybersecurity.
• Conduct joint risk assessments and tabletop exercises around industrial threats.
• Establish clear incident‑response processes for IoT and ICS events.

Policies and protocols for secure IoT networks

Technology alone isn’t enough. Effective IoT cybersecurity also relies on strong governance.

• Define policies for device onboarding, configuration baselines, and decommissioning.
• Require security reviews for new IoT devices, including third‑party risk assessments.
• Document approved protocols, encryption standards, and remote‑access methods.
• Ensure that contracts with solution providers cover security IoT devices requirements, updates, logging, and incident reporting.
• Align IoT security controls with frameworks such as NIST’s Cybersecurity for IoT Program and sector‑specific regulations for critical infrastructure.

Clear policies and processes help organizations consistently manage risk as their fleets of connected devices grow.

Future trends in IoT cybersecurity

As technology evolves, so do cyber threats. Expect to see:

• AI‑driven attacks and defense – Adversaries will use automation to probe systems; defenders will counter with ML‑based anomaly detection.
• 5G and edge computing – Ultra‑low‑latency networks and edge analytics will increase the number of IoT devices outside traditional perimeters.
• Stronger OT security regulations – Governments will continue to issue requirements for critical industrial environments.
• Secure‑by‑design initiatives – More manufacturers and developers will adopt secure coding standards and hardware roots of trust.

IT professionals who understand IoT cybersecurity and can bridge the gap between IT and OT will be in high demand.

Building your IoT cybersecurity career with CompTIA

Securing IoT devices, industrial control systems, and mixed IT/OT environments requires a broad set of cybersecurity skills:

• Fundamentals of network and cloud security
• Hands‑on experience with intrusion detection, incident response, and defense‑in‑depth
• Familiarity with OT security concepts and critical‑infrastructure systems

CompTIA’s vendor‑neutral certifications help you build and validate these capabilities:

• CompTIA Security+ – Establishes core cybersecurity knowledge, including threats, vulnerabilities, risk management, and secure network design.
• CompTIA CySA+ – Focuses on monitoring, detection, and responding to cyber threats across complex systems, including IoT devices and cloud workloads.
• CompTIA PenTest+ – Develops offensive skills for testing IoT and OT systems against real‑world cyberattacks.

If you’re ready to turn interest in IoT cybersecurity into a practical, job‑ready skill set, start by earning CompTIA Security+. Security+ gives you the baseline security knowledge employers expect when they trust you to protect IoT devices, systems, and critical infrastructure from modern threats.

Learn more about the CompTIA Security+ certification and download the exam objectives today.