What Is IoT Security?

The Internet of Things (IoT) has transformed how businesses operate, with over 30 billion connected devices (or four devices per person) in 2025. However, this exponential growth introduces critical vulnerabilities—from unsecured smart sensors to legacy industrial systems—creating entry points for cyber-attacks targeting corporate networks.

IoT security has become an integral component of enterprise cybersecurity strategies, focusing on safeguarding interconnected ecosystems against data breaches, ransomware, and operational disruptions while enabling innovation in supply chain management, healthcare, and smart infrastructure.

IoT security refers to the practices, technologies, and policies designed to protect internet-connected devices—from sensors and cameras to industrial control systems—and their networks. Unlike traditional cybersecurity, IoT security addresses unique challenges like device heterogeneity, limited computational power, and the convergence of physical and digital risks. Its goals extend beyond safeguarding data to ensure operational continuity, preventing unauthorised access to critical infrastructure, and mitigating threats like ransomware that exploit vulnerable smart devices.

Take the healthcare industry, for example, where IoT devices (e.g., patient monitors and MRI machines) lack encryption and are prone to medical device ransomware. In turn, reports indicate that 43% of healthcare organisations in the U.S. have experienced a ransomware attack, and 76% of those experienced an average of three or more. Fifty-five percent of organisations in that report indicate experiencing at least one cyber-attack in the last two years that involved an IoT or IoMT device.

With a vast majority of cyber-attacks and breaches linked to unpatched firmware and default credentials, organisations now prioritise strategies like network segmentation, zero-trust frameworks, and AI-driven threat detection to secure IoT deployments without stifling innovation.

IoT devices encompass any device that connect to the cloud and collect data, with the notable exception of mobile phones, which are typically classified separately due to their complex functionalities and widespread personal usage. It could be locks, garage door openers, temperature monitors (such as Google Nest), refrigerators, security cameras, ovens, televisions, or any other gadget that connects to the cloud. Notice that these devices are not mobile devices, which have a standard operating system and their own cybersecurity standards. IoT devices typically run lightweight, embedded operating systems (e.g., Linux variants) with limited resources for built-in protections.

IoT Security Demands Unique Cybersecurity Protocols

Because IoT devices work differently than standard mobile devices, they require their own set of cybersecurity rules unique to how they operate. They don’t have the advantage of security rules inherent with a mobile device such as iOS and Android. When IoT first became popular, several attacks were launched against these devices that caused disastrous data breaches. Even today, IoT security is still a challenge for many developers and manufacturers. The lack of standardised security protocols across manufacturers further complicates efforts to secure these devices.

IoT security protects data moving from the local device to the cloud and safeguards the device itself from compromise. A malware called Mirai has become a significant threat because users rarely change the default password for IoT devices. Mirai targets IoT devices that run Linux with active default passwords and makes the device a part of a botnet. This botnet is then used to launch a distributed denial-of-service (DDoS) against a target. Simply changing the default password and blocking Telnet services can mitigate Mirai’s brute-force attack on IoT devices.

Securing IoT Data Transfer and Data Storage

Because IoT devices communicate with the cloud, security must also involve protecting transferred data and the location where it’s stored. The cloud stores a myriad of data points that could be used for identity theft or intrusion of the user’s privacy if an attacker can compromise the user’s account. Although many website owners work with SSL/TLS on data transfers, some IoT device manufacturers have transferred sensitive information without encryption, leaving data vulnerable to interception by attackers.

Encryption and Authentication are Vital

Authentication issues have also plagued IoT security. For example, weak or missing authentication in industrial sensors or consumer-grade devices has allowed attackers to gain unauthorised access to sensitive operational data or user accounts. Better authentication tools and protection from brute-force password attacks stop attackers from obtaining this information.

There is no one way IoT security works. Still, it’s been a goal for cybersecurity professionals to educate developers and manufacturers on the proper methods of coding with security and placing better protections on cloud activity. IoT security includes encrypting data travelling in the cloud, better password controls, and coding IoT actions that defend against attacker-controlled scanners and tools. With no accepted standards, securing IoT ecosystems falls largely on manufacturers and end-users, who must work together to mitigate risks while enabling innovation.

Securing IoT devices is a complex task that requires addressing vulnerabilities at every stage—from manufacturing to user interaction. Below are some of the most pressing challenges in IoT security:

• Default passwords and user awareness: Many IoT devices ship with default passwords, which users often fail to change due to a lack of awareness or convenience. This creates a significant security risk, as malware like Mirai exploits these default credentials to hijack devices for botnet attacks.
• Lack of firmware updates: Even when manufacturers release updates to address vulnerabilities, users often neglect to install them. Without regular firmware updates, IoT devices remain exposed to known exploits for months. Many users are unaware of update availability or do not prioritise checking for them, leaving devices vulnerable to attacks.
• Absence of standardised security protocols: Unlike mobile devices or web applications, IoT security lacks universally accepted standards. This “wild, wild west” approach forces developers to create their own security frameworks, often falling short of addressing advanced threats. The inconsistency across manufacturers leaves gaps in protection and increases the attack surface.
• Insecure development practices: Developers and manufacturers frequently underestimate the risk of IoT devices, leading to insecure coding practices and insufficient testing. Many IoT products are released without thorough penetration testing or vulnerability assessments, leaving critical flaws unaddressed.
• Limited device resources: IoT devices often have limited processing power and memory, making it difficult to implement robust security measures like encryption or intrusion detection systems. These resource constraints force manufacturers to prioritise functionality over security, leaving devices more susceptible to attacks.
• Cloud and data security risks: IoT devices frequently communicate with cloud platforms to store and process data. If cloud connections are not encrypted or properly secured, attackers can intercept sensitive information or compromise user accounts. The lack of consistent encryption practices among manufacturers exacerbates this issue.
• Supply chain vulnerabilities: Many IoT devices rely on third-party components or software libraries, which may introduce hidden vulnerabilities. Manufacturers often have limited visibility into the security of these components, making it harder to ensure end-to-end protection for their products.

Addressing these challenges requires collaboration between manufacturers, developers, and users—focusing on education, proactive development practices, and the adoption of emerging regulatory standards for IoT security.

“As more and more devices are activated and begin accessing personal and corporate data and systems, it’s important to understand the implications of installing and using these products,” warns Gretel Egan, Proofpoint Security Awareness Training Strategist.

These devices often prioritise functionality over security, creating entry points for cyber-attacks that threaten both privacy and operational continuity.

Common IoT Security Risks

The following vulnerabilities are frequently exploited in IoT ecosystems due to inherent design flaws and oversight:

• Unauthorised access via weak authentication: Default or reused passwords plague IoT ecosystems, with breaches commonly tied to unchanged credentials. Devices like security cameras or smart thermostats often lack multifactor authentication (MFA), allowing attackers to hijack accounts or infiltrate networks.
• Interception of unencrypted data: Many IoT devices transmit sensitive data (e.g., health metrics, GPS locations) without encryption, leaving records vulnerable to eavesdropping or manipulation.
• Firmware vulnerabilities: Outdated firmware leaves devices open to exploits, as manufacturers often delay critical patches, giving attackers time to deploy ransomware or spyware.
• Insecure communication channels: IoT protocols like MQTT or CoAP, if unsecured, allow attackers to inject malicious commands, such as triggering equipment damage in smart grids.
• Physical tampering: Poorly secured edge devices (e.g., environmental sensors in remote locations) are vulnerable to physical manipulation, enabling attackers to bypass digital safeguards.

Impact of IoT Security Breaches

Compromised IoT devices can trigger domino effects across personal, corporate, and even societal infrastructure:

• Data theft: Compromised devices leak personally identifiable information (PII), trade secrets, or operational data. A breach involving 2.7 billion IoT grow light records exposed Wi-Fi credentials and device IDs, enabling corporate espionage.
• Operational disruption: Attacks on industrial IoT systems can halt production lines or disable critical infrastructure.
• Botnet recruitment: Hijacked devices—like IP cameras or routers—are weaponised for DDoS attacks, as seen in the Mirai botnet, which disrupted major platforms.
• Lateral network attacks: A single compromised IoT thermostat or HVAC system can be a gateway to infiltrate corporate databases.

By addressing these risks proactively, organisations can harness IoT innovation while safeguarding against escalating cyber threats. As regulations tighten, a blend of technical safeguards and user education will define IoT security success.

Securing IoT devices requires a combination of user actions, manufacturer best practices, and advanced security tools. While user education is critical in mitigating risks, manufacturers and organisations can adopt specific tools and strategies to strengthen IoT security. Below are some effective approaches:

Network Access Control (NAC) Systems

NAC solutions enforce policies that control which devices can access a network, ensuring only authenticated and authorised devices are allowed. By profiling IoT devices based on their type and compliance status, NAC can quarantine non-compliant devices or restrict their access to sensitive resources. This is particularly useful for managing the growing number of IoT endpoints in industries like healthcare and manufacturing, where unauthorised access can lead to significant breaches.

Segmented Network Designs

Network segmentation divides a network into smaller, isolated segments with specific security rules for each. This approach limits the movement of threats within a network if an IoT device is compromised. For example, critical systems like databases or production equipment can be separated from less secure IoT devices, reducing the risk of lateral movement attacks. Micro-segmentation takes this further by applying fine-grained policies to individual devices or workloads, enhancing containment capabilities.

Strong Authentication Mechanisms

Replacing default passwords with strong, unique credentials is crucial for securing IoT devices. MFA adds an additional layer of protection by requiring users to verify their identity through multiple methods. In industrial IoT (IIoT) environments, using certificates or digital signatures ensures device authenticity and prevents unauthorised access.

Regular Firmware Updates

Keeping device firmware up to date is essential for addressing vulnerabilities as they are discovered. Automated update mechanisms can help users apply patches promptly without requiring manual intervention. Organisations should also monitor for available updates regularly to minimise exposure to known exploits.

Data Encryption

Encrypting data both in transit and at rest protects sensitive information from interception or tampering. Many IoT devices transmit data to cloud platforms, making robust encryption protocols like TLS/SSL critical for securing communication channels and preventing adversary-in-the-middle attacks.

Blocking Unnecessary Ports

Attackers often scan networks for open ports that can be exploited to access IoT devices. Closing unused ports—such as Telnet—and restricting access to essential services reduces the attack surface and prevents unauthorised entry points into the network.

Continuous Monitoring and Threat Detection

Implementing tools that monitor device behaviour in real time can help detect anomalies or unauthorised activity early. AI-driven monitoring solutions can identify unusual patterns, such as unexpected data spikes or unauthorised access attempts, enabling swift responses to potential threats.

Aaron Jentzen, Senior Programme Content Writer at Proofpoint Security Awareness Training, highlights in a post about IoT purchases and security risks, “While unconcerned consumers might benefit most from security awareness training and information about IoT security, everyone should have an understanding of the security concerns related to these devices—and a healthy degree of caution.”

To that end, “Proofpoint created a helpful Q&A and checklist to help people better understand IoT devices and the steps they should take to improve IoT security,” Jentzen adds.

To safeguard connected ecosystems, businesses must align with evolving regulatory mandates and adopt technical safeguards tailored to IoT’s unique risks. Below are essential requirements to address:

• Regulatory compliance: Adhere to region-specific regulations like the EU’s Cyber Resilience Act (mandating vulnerability disclosures) and the U.S. Cyber Trust Mark (certifying device security).
• Password policies: Eliminate universal default passwords, as required by the UK’s Product Security Regime and EU’s ETSI EN 303 645 standard.
• Unique credentials: Assign cryptographic identities (e.g., X.509 certificates) and use hardware security modules (HSMs) to store credentials.
• Firmware updates: Automate patch management to address vulnerabilities promptly, minimising exposure to exploits.
• Network segmentation: Isolate IoT devices from critical systems to contain breaches and limit lateral movement.
• Zero-trust architecture: Continuously verify device and user identities, treating all connections as untrusted by default.
• AI-driven threat detection: Deploy tools to identify anomalies (e.g., abnormal sensor activity) in real time.
• Regular audits: Conduct penetration testing and third-party vendor assessments to ensure compliance with standards like ISO 27001.

Failure to meet these requirements risks penalties, operational disruptions, and reputational damage. By integrating security into IoT design and operations, businesses can balance innovation with resilience in a hyperconnected world.

Proofpoint empowers organisations to secure IoT ecosystems by addressing vulnerabilities at both the device and human layers. With Proofpoint Data Security Posture Management, businesses gain visibility into misconfigured IoT devices and overprivileged accounts, enforcing zero-trust principles to isolate devices from critical systems and eliminate weak authentication practices. This solution automates compliance checks and reduces attack paths linked to unsecured cloud-connected sensors or industrial controllers.

Complementing this, Proofpoint Adaptive AI Email Security blocks phishing attacks that target employees managing IoT infrastructure, preventing credential theft or malware delivery. By neutralising malicious links and spoofed firmware updates in real time, Proofpoint ensures human error doesn’t escalate into IoT breaches. Together, these solutions provide a layered defence against botnet recruitment, data leaks, and lateral network attacks, enabling enterprises to harness IoT innovation securely. Contact Proofpoint to learn more.