Smart plugs, lights, sensors, and cameras — our homes are packed with connected devices. But how secure are they, really? In response to growing cybersecurity risks, the European Union is launching mandatory EU IoT security labels for smart devices starting in 2025.
This new rule won’t just affect big manufacturers. If you’re into flashing ESP32 boards, setting up DIY smart homes, or sharing your own creations, you might be part of the picture too.
Here’s what these new rules mean — especially if you like to tinker.
What Are EU IoT Security Labels?
The EU’s upcoming security label is part of a broader effort to make smart devices safer and more transparent. Two main legal frameworks are driving this:
- The Cyber Resilience Act (CRA)
- The updated Radio Equipment Directive (RED)
The labels will be mandatory for all smart devices sold in the EU — including Wi-Fi sensors, smart plugs, hubs, and more.
Each EU IoT security label will include:
- Confirmation of compliance with EN 303 645, a widely adopted IoT security standard
- Information about software update policies
- Details on data protection and secure communication practices
Think of it like a nutrition label for IoT — giving users a clear view of how secure (or not) a device really is.
Why It Matters for DIY Builders
At first glance, these regulations seem aimed at big brands — the Amazons, Xiaomis, and TP-Links of the world. But if you’re building your own ESP32-based gadgets, or even flashing commercial devices with custom firmware, you’re not entirely outside the scope.
Here’s why DIY tinkerers should care.
You Might Be a “Manufacturer” Without Realizing It
According to EU rules, anyone who places a product on the market — even in small quantities — can be considered a manufacturer. That means if you:
- Sell custom-made IoT devices
- Distribute flashed smart plugs with Tasmota
- Install DIY sensors for clients or even friends
…you may fall under these compliance requirements.
Modifying Firmware Can Void Compliance
If you take a compliant product (like a Shelly device) and flash it with custom firmware (like ESPHome or Tasmota), you might inadvertently remove its official security certification. That’s fine for personal use, but things get murky if you share it.
Open-Source Doesn’t Automatically Mean Secure
Many open-source projects prioritize features over hardening. If your device doesn’t support secure updates, strong password policies, or encrypted communication, it likely wouldn’t pass the new EU IoT security label requirements.
4 Ways This Impacts Your IoT Projects
Even if you’re building devices just for personal use today, it’s worth knowing how these rules shape the future of DIY and open-source hardware. Here are four specific ways your projects might be affected.
1. Custom Firmware Might Void Compliance
Flashing firmware like ESPHome, Tasmota, or even your own Arduino sketches can give you full control over your device — but doing so will likely break the original compliance that the device had when shipped. If the original firmware met EU standards, your version might not.
This is especially relevant for popular projects like:
- Flashing Tuya-based devices to remove cloud dependence
- Modifying off-the-shelf sensors for custom data formats
- Using OTA updates with custom-built firmware
Related read: ESP-NOW with a Wi-Fi Gateway – Go Cloudless with ESP32
2. Default Passwords Are a No-Go
Devices must not use hardcoded or default credentials like admin/admin. EU rules require either:
- Automatic generation of strong unique passwords, or
- A mandatory prompt during setup to create one
This could impact projects where you:
- Reuse templates without login protection
- Expose MQTT brokers or web interfaces
- Assume your LAN is “secure enough”
3. OTA Updates Might Be Required
The EU mandates that compliant devices provide secure, user-accessible software updates — including for known vulnerabilities.
In the DIY world, this means:
- You should implement OTA firmware updates (like those offered by ESPHome or ArduinoOTA)
- Or provide clear, manual update instructions (e.g., via serial or SD card)
Without update paths, your device could be flagged as insecure under the new system.
4. Documentation Is Now a Security Feature
Security labels don’t just rate the hardware — they also reflect how well users are informed and protected.
If you release open-source projects, think about including:
- Clear setup steps
- Warnings about default settings or exposed ports
- Update procedures
- Basic hardening advice
What used to be “nice-to-have” is quickly becoming “must-have.”
How to Future-Proof Your Builds
You don’t need to stop tinkering — but it’s smart to start designing with security in mind, especially if your DIY projects might someday leave your home lab.
Use Trusted Components and Firmware
Stick to components and modules with transparent documentation and a strong track record in the open-source community. Avoid cloud-tied or locked platforms like Tuya unless you plan to reflash them immediately.
For microcontrollers and firmware, consider:
- ESPHome
- Tasmota
- WLED
- OpenMQTTGateway
These options support local control, secure updates, and often include built-in protection mechanisms.
Design for OTA (Over-the-Air) Updates
Secure firmware updates are one of the key requirements under the new EU standards. Most ESP32 platforms support OTA — implement it early, especially for sensors in hard-to-reach places.
Devices that can be updated in the field are not only more secure but also more compliant with the EU IoT security labels framework.
Avoid Black-Box Dependencies
If a module comes with no documentation or requires a proprietary app just to function, it’s probably not security compliant. Black-box hardware makes it nearly impossible to guarantee data handling or secure communication.
Choose devices and modules where you can inspect, modify, and verify both firmware and communication protocols.
Harden Your Default Configurations
Security should be the default, not an afterthought. As you design your IoT project:
- Avoid using default or hardcoded credentials
- Disable unused services like Telnet, captive portals, or exposed APIs
- Use encryption where possible (e.g., TLS for MQTT)
- Limit what ports are open and log any unusual access
These small steps go a long way in making your devices resilient — even without formal certification.
Share With Security in Mind
If you’re publishing your DIY builds online or sharing code, include a short section on how your project handles security. For example:
“This firmware enables OTA updates via
/update. The web interface uses a randomized password, generated on first boot. MQTT access requires authentication.”
Providing this kind of documentation aligns with the EU’s push for transparency — and builds trust within the maker community.
Closing Thoughts
The EU’s new IoT security labels might seem like just another regulation — but for makers, it’s actually a chance to level up. Whether you’re building ESP32-based sensors for your home or sharing DIY firmware with the community, security is no longer optional.
This shift doesn’t mean the end of open-source tinkering. On the contrary, it’s a call to build smarter, more resilient, and more transparent devices. If your project can stand up to the same scrutiny as commercial hardware, that’s a win not just for compliance — but for your users, your data, and the open-source movement itself.
As the 2025 deadline approaches, expect more updates across open-source platforms like ESPHome and Tasmota, making it easier to stay secure without sacrificing flexibility. For now, the best thing you can do is stay informed and start building with these principles in mind.
If you’re already thinking about long-range, local, and cloud-free IoT, check out our article on how we used ESP32 and LoRa to monitor a vineyard off-grid. It’s a great example of designing with independence and security from the start.