IoT Penetration Testing: Why It Matters and How It’s Done

The count of IoT-connected devices worldwide is expected to reach 40.6 billion by 2034. This explosive growth in the Internet of Things (IoT) brings massive cybersecurity challenges, expanding attack surfaces, and stricter compliance requirements. 

IoT penetration testing is a crucial cybersecurity exercise that simulates attacks on IoT (Internet of Things) devices to uncover security weaknesses before attackers do. It is often used in conjunction with IoT vulnerability assessments to identify and validate risks.

What is IoT Penetration Testing?

IoT penetration testing is the process of simulating real-world cyberattacks on IoT devices, networks, and applications to uncover security vulnerabilities before threat actors exploit them.

It tests the resilience of IoT ecosystems, which include everything from smart thermostats and industrial sensors to connected cars and medical devices.

Unlike traditional pen tests, Internet of Things penetration testing spans both hardware and software layers. It involves analysis of embedded firmware, insecure interfaces, APIs, and even physical device access.

Common IoT Security Threats

Common IoT securitythreats include device hijacking, data exfiltration, unsecured networks, malware infections, and insider threats. These attacks exploit weak configurations and poor network controls to steal data, disrupt operations, or take control of connected devices.

Device Hijacking

Attackers gain unauthorized control over IoT devices to manipulate functions, disrupt operations, or cause physical harm, especially in sectors like healthcare or manufacturing.

Data Exfiltration

IoT devices continuously collect and transmit data, making them prime targets for attackers aiming to steal sensitive business or personal information.

Unsecured Networks

Many IoT devices connect over poorly secured or unsegmented networks, allowing attackers to intercept communications or move laterally across systems.

Malware Attacks

IoT malware such as Mirai can infect devices and create botnets, spread ransomware, or disable connected services.

Outdated or Unpatchable Firmware

Many IoT devices lack over-the-air (OTA) update capabilities or vendor support, leaving known vulnerabilities unpatched indefinitely.

Hardcoded Credentials and Weak Authentication

Hardcoded admin passwords, default logins, or lack of MFA are still widespread in consumer and industrial IoT, making brute-force or credential stuffing easy.

Insider Threats

Employees, contractors, or third-party vendors with legitimate access may unintentionally or maliciously compromise IoT systems.

Insecure APIs

Poorly secured interfaces can expose device controls, sensitive data, or allow attackers to pivot into cloud-connected environments.

Third-Party Risk

Compromised supply chain components—such as embedded chips, libraries, or cloud services—can expose entire device fleets to systemic risk.

Physical Tampering

IoT devices deployed in public or remote areas are often vulnerable to physical attacks like hardware resets, cloning, or malicious firmware injection.

Top Reasons to Conduct IoT Penetration Testing

Organizations conduct IoT penetration testing to proactively identify and fix security flaws that could result in data breaches, device manipulation, or service disruption.

Here are the top reasons to conduct an IoT pen test.

• Protect Customer Data: IoT devices often collect personal and health-related data, making security a privacy imperative.
• Ensure Regulatory Compliance: Sectors like healthcare and energy face strict IoT security mandates.
• Maintain Business Continuity: A compromised device can serve as an entry point into critical infrastructure.
• Preserve Brand Trust: A single breach can lead to loss of customer confidence and reputation damage.
• Enhance Product Resilience: Early use of IoT security testing tools helps manufacturers ship secure-by-design IoT solutions.

How IoT Penetration Testing Works

IoT penetration testing follows a multi-phase methodology, combining manual techniques and automated tools to simulate real threats. This includes the use of IoT pen test tools like Shodan, Wireshark, Binwalk, Firmware Analysis Toolkit (FAT), and Radare2.

1. Threat Modeling

Threat modeling is the first step in IoT pen testing. Testers identify the components of the IoT ecosystem (such as hardware, communication channels, APIs, cloud integrations) and determine the most probable attack vectors.

2. Information Gathering and Reconnaissance

During this phase, testers collect data on the device and ecosystem using IoT-specific reconnaissance tools and passive traffic monitoring. The data gathered includes device documentation and configuration files, firmware dumps, network traffic analysis, open ports and communication protocols.

3. Vulnerability Identification

Testers use automated and manual techniques to detect flaws such as insecure firmware or storage, open Telnet or SSH ports, hardcoded secrets, and weak or missing encryption. IoT vulnerabilities are often found using tools like Firmware Analysis Toolkit (FAT), Binwalk, Shodan, and Radare2.

4. Exploitation and Privilege Escalation

Once vulnerabilities are found, testers attempt to exploit them just as attackers would. For example, they may bypass authentication mechanisms, inject malicious commands into firmware, or escalate privileges from user to admin level.

5. Post-Exploitation Analysis

After successfully exploiting vulnerabilities, testers move into the post-exploitation phase to assess the potential impact of a real-world attack. They examine whether an attacker could pivot to backend servers, extract sensitive data, take control of device functionality, or maintain persistent, undetected access within the network. This phase helps determine the true extent of the security risk.

6. Reporting and Remediation

The final step involves compiling all findings into a detailed report. This includes descriptions of the discovered vulnerabilities, their severity levels, and proof-of-concept examples demonstrating how they were exploited. The report also includes risk scores, business impact analysis, and actionable remediation steps with patching recommendations to strengthen security posture.

Challenges in IoT Pen Testing

IoT pen testing presents challenges due to hardware complexity, diverse protocols, limited documentation, and physical access issues.

Here are the top challenges faced during IoT pen testing.

• Device Diversity: IoT devices use various chipsets, operating systems, and communication standards.
• Limited Testing Tools: Many tools are not suited for embedded systems security testing.
• Firmware Extraction: Requires physical teardown or JTAG/UART interfacing.
• Protocol Fuzzing: Standard pen testing tools often can’t parse proprietary protocols.
• Patch Limitations: In many cases, devices lack secure update mechanisms.