IoT Device Security: Change Defaults, Stay Protected

About 8 min read

Smart speakers, network cameras, smart locks, wearable devices - IoT (Internet of Things) devices are rapidly becoming part of our daily lives. According to research, the number of IoT devices worldwide reached approximately 39 billion in 2024, with further growth expected in 2025. However, many of these devices are operated with weak default passwords and receive insufficient security updates. This article explains the risks lurking in IoT devices and the concrete defensive measures you can implement at home and in the office.

What Should You Do First?

Improve your IoT security in the following order of priority. Beginners should first change the default passwords on all IoT devices to strong passwords generated with Passtsuku.com. Next, use your router's guest network feature to isolate IoT devices on a separate network from PCs and smartphones. Intermediate and advanced users should also strengthen the router admin password, switch to WPA3, and disable UPnP.

Why IoT Devices Are Targeted

Unchanged Default Passwords

Many IoT devices ship with factory-set passwords like "admin", "password", or "123456". Users very often never change these defaults, and attackers know this well. The Mirai botnet used 61 known default passwords to automatically log into IoT devices, causing a massive DDoS attack in 2016. In that attack, DNS provider Dyn was targeted, temporarily making major services like Twitter, Netflix, and Reddit inaccessible. Understanding DNS security helps appreciate the scale of such infrastructure-level attacks. Mirai variants continue to operate today, and observations by NICT (Japan's National Institute of Information and Communications Technology) show that cyberattacks targeting IoT devices account for approximately 30% of all attack traffic.

Limited Update Mechanisms

Unlike PCs and smartphones, many IoT devices lack automatic update capabilities. Firmware updates must be performed manually, and the process can be complex. Furthermore, it is not uncommon for manufacturers to stop providing security patches after just a few years, leaving a large number of devices in use with known vulnerabilities unpatched. A key concern is that end-of-support announcements often fail to reach users adequately - they are typically posted inconspicuously on the manufacturer's website, with no notification sent to the device itself.

Inadequate Encryption

Some IoT devices transmit communication data without encryption, or use deprecated encryption protocols such as SSL 3.0 or TLS 1.0. If an attacker on the same network intercepts the traffic, they can easily obtain sensitive data such as camera footage, audio data, and sensor information. Network cameras in particular sometimes transmit video data in plaintext, and in 2020, approximately 2,000 cameras in Japan were reported to have their footage accessible to third parties. Understanding encryption fundamentals can help you make informed decisions when selecting devices.

To systematically learn IoT security fundamentals, IoT vulnerability assessment guides (Amazon) are helpful.

Practical Security Measures

Change Default Passwords Immediately

The first thing to do after purchasing an IoT device is to change its password. Use Passtsuku.com to generate a unique, strong password for each device. Since IoT device passwords require less frequent manual entry, we recommend setting long passwords of 20 characters or more. A 20-character password containing uppercase letters, lowercase letters, and numbers provides approximately 119 bits of entropy, offering sufficient resistance against brute-force attacks. If the device supports special characters, add those as well to further increase strength.

Create a Dedicated IoT Network

Connecting IoT devices to the same network as PCs and smartphones means that if one IoT device is compromised, the entire network is at risk. Many home routers have a guest network feature, so connect IoT devices to the guest network to isolate them from the main network. In enterprise environments, we recommend using VLANs (Virtual LANs) to isolate IoT devices in independent network segments. A common misconception is that guest networks are slower, but without bandwidth restrictions, they can communicate at the same speed as the main network.

Keep Firmware Updated

Regularly check your IoT device firmware and apply updates promptly when available. For devices without automatic update capabilities, we recommend making it a habit to check the manufacturer's support page once a month. Firmware updates often include security patches and are an important means of fixing known vulnerabilities. Cutting power during an update can cause device failure, so keep the power stable during updates and wait for completion.

Disable Unnecessary Features

Actively disable features you don't use. Remote access, UPnP (Universal Plug and Play), voice assistant integration - every enabled feature is a potential attack target. UPnP in particular is a feature that allows devices to automatically open ports on the router, which can become an entry point for unauthorized external access. Keeping only necessary features enabled and minimizing the attack surface is a fundamental security principle. Don't overlook physical access control for IoT devices either - software measures alone are insufficient when someone can physically reach the device.

Securing Your Router

Your router is the gateway to all IoT devices on your network. If the router's security is weak, every connected device is at risk.

• Change the router admin password to a strong password generated with Passtsuku.com
• Set Wi-Fi encryption to WPA3 (or WPA2 if WPA3 is not supported)
• Disable WPS (Wi-Fi Protected Setup) due to its known vulnerabilities
• Keep the router firmware up to date
• Change the default SSID to a name that doesn't reveal the router model

When considering a router upgrade, WPA3-compatible Wi-Fi 6E routers (Amazon) support the latest security standards. Network segmentation also helps contain ransomware spread if an IoT device is compromised.

How to Choose Secure IoT Devices

When purchasing IoT devices, include security as an important selection criterion. Check whether the manufacturer provides regular security updates, supports strong authentication methods (such as two-factor authentication), has a clear privacy policy, and implements data encryption. For IoT devices that handle biometric data, such as smartwatches and health monitors, medical data protection considerations are especially important. Products from cheap, unknown manufacturers often have insufficient security measures, so choosing products from reputable manufacturers leads to better long-term security. Since 2024, the EU has enforced the Cyber Resilience Act, mandating that IoT products comply with security requirements. Choosing products with the CE mark can also serve as an indicator of security quality. By setting unique passwords for each device using Passtsuku.com and regularly updating them, you can significantly improve the security of your entire IoT environment.

Take Action Now

1. List all IoT devices in your home (cameras, speakers, routers, etc.) and check if any are still using default passwords
2. Generate passwords of 20+ characters with Passtsuku.com and change passwords on all IoT devices individually
3. Enable the guest network feature on your router and connect IoT devices to a separate network from PCs and smartphones
4. Strengthen the router admin password with Passtsuku.com and set Wi-Fi encryption to WPA3 (or WPA2)
5. Check firmware updates for each IoT device and update to the latest version

Frequently Asked Questions

What damage can occur if an IoT device is attacked?

Privacy violations (camera/microphone eavesdropping), recruitment into botnets for DDoS attacks, and use as a stepping stone to infiltrate your entire home network.

Do I need to change the default password on IoT devices?

Absolutely. Factory default passwords are publicly available online, and malware like Mirai automatically takes over devices using default credentials.

What is the first thing to do for IoT device security?

Prioritize three things: change default passwords, update firmware, and isolate IoT devices on a separate network (VLAN or guest Wi-Fi).