OWASP IoT Security Testing Guide

The OWASP IoT Security Testing Guide (ISTG) is a comprehensive resource to help security professionals conduct IoT penetration testing on Internet of Things (IoT) devices and systems. It provides a structured methodology that encompasses various aspects of IoT security testing, from device and attacker modeling to testing methods and a catalog of test cases.

IoT Security Testing Framework

To perform an effective penetration test on IoT devices, it is important to define the test scope (what to test) and test perspective (how to test). This guide suggests a three-step approach:

• Device model: Create a generalized model of IoT devices to identify testable components.
• Attacker model: Define potential attacker types to determine the test perspective.
• Test methodology: Develop a general test methodology based on the device model and the attacker model.

Test case catalog

This section provides a detailed list of test cases tailored to the various components of an IoT device.

3.1. Processing Units (ISTG-PROC):

This defines test cases for the device's processing unit. This includes tests for vulnerabilities in software running on the processing unit, such as buffer overflows, insecure programming practices, and inadequate authorization controls.

3.2. Memory (ISTG-MEM):

This section focuses on the security of the device's memory. Testing includes checking for vulnerabilities such as insufficient access controls, the possibility of gaining unauthorized access to the memory, or storing sensitive data in unencrypted form.

3.3. Firmware (ISTG-FW):

This area focuses on the device's firmware, which controls basic functionality.

3.3.1.

Installed Firmware (ISTG-FW[INST]): This is where tests are run to check the security of the installed firmware, including searching for known vulnerabilities, insufficient authentication and authorization, and checking the integrity of the firmware.

3.3.2.

Firmware Update Mechanism (ISTG-FW[UPDT]): This part deals with the mechanism for updating the firmware. Tests include checking the security of the update process, including authentication, checking the integrity of updates and the possibility of installing fake updates.

3.4. Data Exchange Services (ISTG-DES):

This section is concerned with the services responsible for exchanging data between the device and other systems. Tests include checking the security of protocols used for data exchange, including encryption, authentication and authorization.

3.5. Internal Interfaces (ISTG-INT):

This tests the device's internal interfaces, including communication between different components within the device. Tests include checking for vulnerabilities in communication, such as inadequate access controls and the possibility of manipulating communication.

3.6. Physical Interfaces (ISTG-PHY):

This section addresses the physical interfaces of the device, such as USB ports, Ethernet ports, and serial ports. Testing includes checking for physical security risks, such as unauthorized access to interfaces, manipulation of data, and executing malicious code via physical interfaces.

3.7. Wireless Interfaces (ISTG-WRLS):

This area covers the device's wireless interfaces, such as Wi-Fi, Bluetooth, and Zigbee. Testing includes verifying the security of wireless communications, including encryption, authentication, and authorization.

3.8. User Interfaces (ISTG-UI):

This section deals with the device's user interfaces, such as web interfaces, mobile apps, and physical controls. Tests include checking for vulnerabilities in the user interfaces, such as cross-site scripting (XSS), SQL injections, and insufficient authorization controls.

Conclusion

The OWASP IoT Security Testing Guide's test catalog provides a structured method for comprehensively assessing the security of IoT devices through a pentest. By performing the tests defined in this catalog, vulnerabilities can be identified and mitigated to increase the security of IoT systems.