Platform firmware is the core low-level software built into a device to initialize hardware, start the operating system, and support recovery if startup fails. It includes code such as BIOS/UEFI on PCs and similar startup logic on servers and embedded systems. Because it runs before the OS, it sits below many endpoint security tools and is often harder to inspect or patch.
This matters because a flaw in platform firmware can affect the entire machine, not just one application. Attackers may target it to gain persistence, survive reinstalls, or interfere with boot integrity. Defenders treat it as security-critical by monitoring firmware versions, applying vendor updates carefully, verifying boot measurements, and planning recovery paths such as secure restore media or remote management. In risk triage, firmware issues are often prioritized based on exposure, exploitability, and whether the device can be safely updated without disrupting operations.