Protecting Your IoT Infrastructure: Essential MQTT Security Practices

The Internet of Things (IoT) has connected the world like never before. Yet, with great power comes a greater risk of cyber-attacks and data breaches. In fact, IoT attacks topped over 10.54 million worldwide in December 2022 alone. With that said, prioritizing MQTT security, as one of the most widely used IoT messaging protocols, is critical.

If you aim for reliable MQTT-based IoT deployments, keep reading this post. We’ll dwell on MQTT security best practices like authentication, encryption, and access control and guide you through implementing these measures. Having used MQTT in our IoT projects, WebbyLab specialists have profound experience safeguarding businesses against cybersecurity threats and are ready to share practical insights.

IoT Security Vulnerabilities: Overlooking Critical Risks in Device Deployments

Common IoT security vulnerabilities

Before diving into security measures, look at the MQTT security vulnerabilities more closely, as that can expose your system to potential cyber security threats. These vulnerabilities often stem from choosing unsuitable technology or a simple oversight. However, the consequences can be dire. Let’s explore the most common factors that can put your IoT devices at risk:

• Weak Authentication

Many IoT devices come with default usernames and passwords, which are easily guessable or widely known. While their users forget to set up unique credentials, attackers can leverage this vulnerability to access the device, control it remotely, and ultimately steal sensitive data.

• Poor Encryption

Without proper encryption, attackers can intercept and modify the data transmitted between devices. It leaves your IoT ecosystem vulnerable to cyber-attacks, so you should take care of MQTT security to provide a robust channel for IoT data in transit and at rest.

• Insufficient Access Controls

Weak access controls are another significant vulnerability in MQTT security IoT. Attackers can exploit it to gain unauthorized access to devices or networks.

• Poorly Configured Devices

Similarly to default passwords and usernames, IoT devices come pre-configured out of the box. Users frequently forget to adjust these devices for their specific deployment environment, leaving their IoT systems vulnerable to attacks.

• Lack of Security Updates

Another vulnerability that puts IoT devices at risk is neglecting regular firmware updates. It also applies to overlooking using the latest security patches.

As an IoT system owner or enthusiast, consider the above vulnerabilities before MQTT deployment to protect against cyber threats and maintain a secure environment.

Three MQTT Security Principles: Elevating Your IoT Security Strategy

Knowing the fundamentals of securing MQTT systems is essential for deploying a reliable IoT network. Here are the three principles you should follow to reinforce MQTT protection:

• Encryption

MQTT operates on a transmission control protocol (TCP), which does not use encryption by default. It poses the risks associated with the confidentiality and integrity of data transmitted between IoT devices. Thus, it’s critical to provide encryption by leveraging Transport Layer Security (TLS) or Secure Sockets Layer (SSL) certificates.

• Application-Layer Authentication

Application-layer authentication is another MQTT security principle ensuring that only authorized devices and clients can communicate. MQTT supports a range of authentication mechanisms, including username and password authentication at the application level, client certificate authentication (X.509 certificate), or a centralized authentication mechanism (OAuth 2.0).

• Authorization

An MQTT client can publish messages or subscribe to topics after successfully authenticating at an MQTT broker. That’s when the third security principle comes in. Authorization helps to ensure that only authorized users or devices are granted access to specific resources or data. An MQTT protocol supports such authorization mechanisms as access control lists (ACLs) and role-based access control (RBAC).

By following these fundamental principles, MQTT-based systems can create a layered security mechanism that provides comprehensive protection against cyber threats.

MQTT Security IoT Best Practices to Follow

Now that you know the fundamental principles of MQTT protocol security, it’s time to dive into how to implement those and other critical measures to protect your IoT system. Here are some essential and actionable MQTT security best practices to consider:

• Use a Unique Username and Password

One of the most basic security practices involves using a unique username and password for authentication when connecting to the MQTT. This way, only authorized device users with the correct credentials can connect to the broker.

• Leverage an Access Control List (ACL) File for Access Control

An ACL is a security algorithm that defines which devices or users can access specific MQTT topics or actions. Using it, you can set up permissions for each client ID, allowing only authorized users to access data.

Providing the MQTT server security.

• Use Strict Access Permissions

When setting up access permissions, ensure you grant only the necessary permissions to each device or user. Don’t hesitate to implement the strictest measures, as it minimizes the risk of unauthorized access to sensitive data or actions.

• Stop Using Wildcards in Topic Names

Wildcards can be used in MQTT topic names to subscribe to multiple topics simultaneously. However, using them can lead to unintentional data leakage or access to data that should be restricted. You can ensure the best device access by avoiding them and being specific about the topics.

• Leverage Unique Client IDs

Each IoT device connected to the MQTT broker must have a unique client ID. That ensures that every device in the ecosystem is correctly identified and prevents unauthorized clients from accessing the broker.

• Establish a Bridge for Remote Connections

If your IoT devices need to connect to an MQTT server via the internet, you better not do this by opening a port on the firewall. The best solution involves a bridge, an intermediary between the remote devices and the MQTT broker. It enables secure connection and prevents unauthorized access and data breaches.

• Throttle MQTT Clients

Throttling MQTT clients involves setting up rate limits to restrict the number of messages a client can send or receive per unit of time. This strategy is critical because a high volume of messages can impact network performance, potentially leading to DoS/DDoS attacks. You can implement throttling by configuring the MQTT broker to set a maximum rate limit for a client based on its IP address or client ID.

• Monitor MQTT Broker Logs

Monitoring your broker logs is a critical MQTT security IoT best practice that helps detect and respond to suspicious activities. By regularly reviewing logs, you can identify any unusual patterns of behavior or attempts to access unauthorized topics. Owing to that, you can also take appropriate measures to prevent potential security breaches.

• Use a VPN

Finally, you can use a VPN to protect the MQTT communication between devices and brokers. A virtual private network creates an encrypted tunnel between two points, allowing secure data transmission over the internet. Owing to this strategy, you can also hide the IP addresses of devices, making it more difficult for attackers to target them.

You can leverage the above IoT applications tips to secure your IoT system and ensure safe device-to-device communication.

Maksym Lesnikov

Chief Technology Officer

Helped dozens of startups create effective digital products.

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MQTT Security IoT Best Practices: WebbyLab Experience

WebbyLab experts use an MQTT automation protocol in most IoT projects and recognize the importance of quality IoT system protection. We leverage the MQTT security Internet of Things best practices described above and even more: everything to prevent data breaches and mitigate cyber threats. Here are our process and tips for delivering MQTT security:

• Implementing MQTTS

We use MQTTS, which suggests encrypted communication between the broker and all clients using TLS/SSL. It requires that both devices use an encrypted connection and clients, i.e., system services, user web applications, mobile apps, etc.

Besides, to implement the MQTTS application protocol, you should remember that certificates may expire. That is why WebbyLab provides devices with over-the-air tools to update the firmware, within the framework of which they also update TLS/SSL.

• Using Proxy

Another way to improve IoT security our team leverages is proxy. It allows us to close the MQTT broker from the outside world, meaning that all clients don’t connect directly to the broker but to a proxy server like NGINX. NGINX, in turn, proxies traffic via TCP or even custom TLS to the broker. Thus, the MQTT remains within the private network.

• Leveraging a Firewall

A firewall allows WebbyLab to control and restrict connections to an MQTT broker for a specific user, IP address, or client ID. We also fine-tune the firewall to deny access to specific clients following particular parameters and protect against brute force.

• Implementing Authorization

The WebbyLab team leverages authorization to grant or deny access to particular users. In addition to the username and password, we use such authorization options as a client ID, digital certificates, JWT tokens, and OAuth.

• Using ACLs

Access control lists provide a way to limit the range of topics and actions to a specific client, and they apply to both devices and clients in MQTT.

We use ACLs to allocate a specific action scope for a device. For example, we grant IoT devices access only to their topics, so they cannot control or hack other connected devices.

At the user level, we use ACLs to configure the scope of access for a particular user, limiting access only to their own devices or certain parts of their gadgets. For example, if an administrator needs full access to an IoT device, but a user requires permission to separate sensors, we configure this through ACLs.

On top of that, our team configures rights within access control lists. For example, we may provide the client with access to subscribe or publish data for specific topics or groups.

• Setting Up the MQTT Broker Properly

Another way to build a secure IoT system involves setting up the MQTT broker properly. Here are a few considerations:

• Set the size of the payload so that huge messages do not clutter the data
• Set the size of topics to prevent the data from cluttering
• Set a rate limit to restrict the number of messages from one device per unit of time

Each MQTT broker has its own settings with which WebbyLab specialists fine-tune the limits according to our client’s business case and requirements.

• Conducting Regular Monitoring

After we set up the broker, it still does not make MQTT secure. Additionally, our experts regularly monitor the logs of the proxy, firewall, and the broker itself to catch new cases of hacking attempts or attacks.

These are our IoT core best practices for securing communication between devices. We leverage them to prevent problems and cyber threats and provide top-notch data security in MQTT.

Protect Your IoT Devices with WebbyLab’s MQTT Security Best Practices

MQTT is a messaging protocol widely adopted across various industries, including machine learning and industrial automation. But the Internet of Things is where it finds the most use. With its ability to provide efficient, reliable, and secure communication between connected devices and systems, MQTT has become an essential tool in the rapidly expanding world of IoT.

Yet, with all this protocol’s advantages, it requires proper data protection measures to mitigate MQTT security issues and vulnerabilities. You can implement the strategies we discussed today to ensure secure communication between devices and the MQTT server and fully rip this protocol’s benefits for your IoT systems.

If you need someone to help you with MQTT security, you can always reach out for expert advice from WebbyLab experts. We have extensive experience implementing MQTT security measures and are ready to deploy your reliable IoT system. Contact us to learn more about how we can assist you in safeguarding your IoT devices.