Vulnerabilities refer to the software and hardware weaknesses that are inherent in the system and can expose the system to threats. System vulnerabilities can be the outcome of how it was designed, implemented, tested, or is operated. While vulnerabilities are unavoidable, proper assessment and proactive remediation techniques need to be employed to combat them.

Vulnerability in any part of the deployment can be subject to an exploit. Experienced cyberattackers are aware of potential vulnerabilities. This makes the attack surface complex and scary. In subsequent chapters, IIoT security strategies and countermeasures will deal with this topic in greater depth.

The following subsections contain a categorized list of common vulnerabilities that are applicable to any cyber-physical IoT security plan (NIST-800-82r2).