IoT devices are vulnerable because they’re built with minimal computing power, rarely receive security updates, and often ship with default passwords and unencrypted communications. These aren’t occasional oversights. They’re structural problems baked into how IoT products are designed, manufactured, and sold. The scale of the problem is enormous: in 2025, IoT devices face an average of 820,000 hacking attempts per day, a 46% jump from the year before.
Understanding why these devices are so exposed requires looking at several layers, from the hardware itself to the business decisions behind it.
Most Devices Ship With Weak Defaults
The single biggest reason IoT devices get compromised is the simplest one: default credentials. Manufacturers ship cameras, routers, smart home hubs, and sensors with factory-set usernames and passwords like “admin/admin” or “root/root.” Most buyers never change them.
The Mirai botnet, one of the most destructive cyberattacks in history, exploited exactly this weakness. Mirai’s code scanned the entire internet for devices with open remote-access ports, then tried to log in using roughly 60 commonly used default username and password combinations. It picked ten at random for each device and brute-forced its way in. That was enough to hijack hundreds of thousands of cameras, routers, and DVRs, then use them to launch massive attacks that temporarily knocked major websites offline. The whole operation relied on nothing more sophisticated than the fact that most people never change factory passwords.
Limited Hardware Means Limited Security
A smartphone has a powerful processor, gigabytes of memory, and a full operating system capable of running antivirus software and encryption. A temperature sensor on an industrial machine or a smart light bulb has a fraction of that computing power. Many IoT devices are built around tiny, low-cost chips designed to do one thing efficiently while consuming almost no energy.
That leaves very little room for security features. Strong encryption, real-time threat monitoring, and secure boot processes all require processing power and memory that these constrained devices simply don’t have. Manufacturers face a genuine engineering trade-off: adding security features can slow performance, increase power consumption, and raise costs on products that often sell for under $50.
Updates Are Rare or Nonexistent
Your phone gets security patches every month. Most IoT devices don’t. Many lack any reliable mechanism for receiving software updates after they leave the factory. Some have no update capability at all.
Several factors make IoT updates uniquely difficult. These devices are often deployed in hard-to-reach locations, like sensors embedded in walls, vehicles, or industrial equipment, where they run continuously without human interaction. They’re frequently engaged in real-time measurement or control loops that can’t tolerate interruption or errors introduced by a bad update. And because many run stripped-down operating systems with minimal storage, there’s often no space to download and stage an update safely.
Even when updates are technically possible, manufacturers may stop supporting a product within a year or two of release. A smart thermostat or connected baby monitor might stay in your home for a decade, but the company that made it has already moved on to newer models. That leaves known vulnerabilities permanently unpatched on millions of devices still connected to the internet.
Unencrypted Communication
Roughly 70% of IoT devices don’t use any encryption for their communications. That means data traveling between a device and its cloud server, or between devices on a local network, can be intercepted and read by anyone positioned to monitor the traffic.
IoT devices commonly use lightweight messaging protocols designed for low-bandwidth, low-power environments. These protocols prioritize efficiency over security. In one documented case, a smart home bridge device transmitted data to its messaging server without encryption, using default credentials. An attacker exploited both weaknesses to take control of the device. This kind of vulnerability isn’t rare. About 60% of IoT devices contain vulnerable interfaces and firmware, making them easy targets for network-based attacks.
The Supply Chain Problem
Many IoT devices from different brands actually run the same underlying software. Manufacturers commonly build products using shared third-party components: networking libraries, operating system kernels, drivers, and firmware packages sourced from a handful of suppliers. A vulnerability in any one of these shared components can ripple across millions of devices from dozens of different companies.
A clear example came in 2020, when researchers discovered 19 vulnerabilities in a low-level networking library developed by a single company called Treck. These flaws, collectively named “Ripple20,” affected millions of devices across industries, including printers, medical infusion pumps, and industrial control systems. Because the vulnerable library was embedded deep in the supply chain, it was extremely difficult to even identify which products were affected, let alone patch them all.
Making this worse, manufacturers routinely incorporate third-party components without maintaining a list of what’s inside their products. When a new vulnerability surfaces in a shared library, there’s often no easy way to determine how many products from the same vendor are affected, or how many devices across different vendors and manufacturers carry the same flaw. Firmware frequently includes deprecated libraries with known vulnerabilities that were never removed or updated.
Physical Ports Left Exposed
Software isn’t the only attack surface. Many IoT devices have physical debugging ports on their circuit boards that were used during development and testing but never disabled before shipping. Two common ones, known as JTAG and UART, give anyone with physical access a direct line into the device’s brain.
Through these ports, an attacker can connect a computer directly to the board, read the contents of memory, extract stored passwords and encryption keys, pause running programs, and redirect the device’s behavior. Security researchers have consistently found these ports active on commercial routers, cameras, and other connected devices. For any IoT product deployed in a publicly accessible location, like a security camera in a hallway or a sensor in a parking garage, these exposed ports are an open invitation.
Economics Work Against Security
IoT is a high-volume, low-margin business. Many connected devices are commodity products competing primarily on price. A manufacturer adding robust security features, ongoing update infrastructure, and long-term software support is adding costs that competitors skip. The result is predictable: security becomes an afterthought.
Consumers typically can’t evaluate the security of a smart plug or connected camera before buying it. There’s no visible difference on a store shelf between a device with strong encryption and regular patches and one with hardcoded passwords and no update mechanism. This information gap means the market doesn’t reward manufacturers who invest in security or punish those who don’t.
Regulation Is Starting to Catch Up
Governments are beginning to address the gap. The U.S. Federal Communications Commission launched the Cyber Trust Mark program, a voluntary labeling system for wireless consumer IoT products based on standards from the National Institute of Standards and Technology. Products that earn the label carry a QR code you can scan to see specific security details: how to change the default password, whether updates are automatic, how to configure the device securely, and the manufacturer’s minimum support period. If a device is no longer supported, the label must say so.
The program is a step toward making security visible at the point of purchase, but it’s voluntary and currently limited to consumer wireless products. Industrial IoT, medical devices, and many other categories remain largely unregulated on the security front. Until security becomes a standard expectation rather than a premium feature, IoT devices will continue to be among the easiest targets on any network.