Which of the following is NOT a common concern related to hardware vendor supply chains?

The question focuses on identifying concerns related to hardware vendor supply chains. Selecting firmware updates as the answer implies understanding what constitutes a typical concern within the supply chain context.

Firmware updates themselves typically do not present a fundamental risk associated with the supply chain; instead, they are a necessary part of maintaining and securing hardware. While the process of updating firmware can have security implications, such as vulnerabilities exploited during the update process or improper implementation leading to security gaps, the updates themselves are a standard practice for ensuring hardware functions optimally and remains secure against known vulnerabilities.

In contrast, third-party hardware modifications, malware on components, and supply chain disruptions are direct concerns. Third-party modifications can introduce unknown risks and vulnerabilities into hardware systems. Malware on components can compromise the integrity and security of devices before they even reach the end-user. Supply chain disruptions can affect availability and lead to rushed production, increasing the chance of vulnerabilities. Thus, the other options reflect recognized risks in the global supply chain environment, making firmware updates the least relevant concern among them.