One of the most common questions I hear from manufacturers is: How often should we do a penetration test?
It’s a fair question. Pen tests aren’t one-size-fits-all, and the right cadence depends on the product, its risk profile, and its regulatory environment. But before we get into that, it’s important to understand why IoT pen testing is different from testing traditional IT systems.
What Makes IoT Pen Testing Different
Unlike traditional IT, IoT requires testing across every layer: firmware, hardware, RF, APIs, mobile apps, and cloud. When I test a connected device, I have to be prepared to:
- Reverse engineer firmware and analyze binaries.
- Probe hardware interfaces like JTAG and UART.
- Assess mobile apps and cloud APIs for weak authentication.
- Monitor RF protocols such as Bluetooth or Zigbee.
- Evaluate physical security and debug access.
It’s a full-stack challenge, where the hardware, software, cloud, and even the physical product itself need to be tested as a single ecosystem. That’s what makes IoT pen testing so critical: the risk isn’t confined to one layer; it’s spread across all of them.
Why It Matters
IoT devices are hybrids. They’re not just small computers; they’re radios, cloud clients, web servers, and physical products all rolled into one. A single weakness in any of those layers can compromise the entire system.
I’ve seen devices with excellent encryption and hardened firmware undone by a debug port left wide open. I’ve also uncovered plain-text keys stored directly in firmware images. These aren’t rare mistakes; they’re the kinds of oversights that attackers actively look for.
That’s why pen testing isn’t a box to check. It’s the only way to validate how all of those components interact in the real world, under pressure from someone thinking like an adversary.
How Often to Test
So how often should you test? At a minimum, every major product release should be pen tested — new hardware revisions, significant firmware updates, or the introduction of third-party components. If the attack surface changes, the testing should change too.
Beyond that, annual testing is a smart baseline. Threats evolve, and a fresh look often reveals new risks in old code.
Industry and Risk Considerations
Not all devices are created equal. In critical industries like healthcare, automotive, and industrial control systems, the risk of failure is measured in human lives and large-scale disruptions. In those cases, pen testing needs to be more frequent and more rigorous, and regulators are reinforcing this.
The EU CRA, FDA 524B, UNECE WP.29, and the Cyber Trust Mark all call for ongoing vulnerability management and independent validation. For many organizations, that means regular testing will soon be a compliance requirement, not just a best practice.
“Annual testing is quickly becoming the minimum standard, not the best practice.”
Why Frequency Matters
The point of penetration testing isn’t to check a box. The goal is to find weaknesses before attackers do. The cadence should reflect that reality. Waiting too long between tests is like leaving the door to your house and hoping no one tries to open it.
But frequency isn’t the whole story. What matters just as much is that the testing is designed for IoT, covering the full ecosystem, from the physical device to the cloud. Anything less leaves blind spots that attackers are all too happy to exploit.
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