Hardware
The physical machine.
What It Is
The hardware is the physical machine, with its processors, memory, disks and network cards. Every other layer, from the firmware to the application, runs on it in the end. That is true in the cloud as well, where the hardware sits in the provider's data centre.
Hardware flaws are rare but deep. Meltdown and Spectre showed that a processor's own design could let one program read memory that belongs to another, beneath the operating system's protections.
Hardware cannot be patched like software. Fixes arrive as firmware and microcode updates, as operating system changes that work around the flaw, or as new hardware.
- App
- Framework
- Web Server
- Runtime
- Containers
- OS
- Hypervisor
- Firmware
- Hardware
- Data
On This Layer
These are the technologies on the Hardware layer that this topic covers. Open one to see what it runs on, how to spot it and what a flaw in it reaches.
How Far a Flaw Reaches
A flaw in the processor or the board sits beneath every other layer, so it can undermine the firmware, the hypervisor and every operating system and virtual machine above it. Physical access to the machine reaches all of it too.