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Hardening - BIOS Password

The BIOS is the foundational firmware that initializes hardware and loads the operating system, and securing it with a password prevents unauthorized changes to critical settings like boot order that could be used to bypass system security.

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About this video

The Basic Input/Output System, or BIOS, is the firmware embedded in a computer that runs before the operating system loads. When a system powers on, the BIOS is the first code executed — it initializes hardware components, then locates and loads the operating system from storage into RAM so the CPU can process it. Without the BIOS, the system has no instructions for how to begin functioning. Because the BIOS governs settings like boot order, it represents a significant security boundary. An attacker with physical access to a machine can enter the BIOS configuration, change the boot sequence to prioritize a USB drive, and use that to boot into an external environment that bypasses operating system-level authentication and security controls entirely. This kind of attack requires no software exploit — just unprotected access to the firmware settings. Setting a BIOS password is one of the most direct ways to mitigate this risk. When a password is configured, accessing the BIOS setup requires authentication, preventing unauthorized users from modifying boot order or other sensitive parameters. This is a standard practice in endpoint hardening and is especially important in environments where devices may be physically accessible to untrusted individuals.

What you'll learn

What's covered

BIOS Security & Basics

Key terms

Basic Input/Output System
BIOS
Firmware stored on a motherboard chip that initializes hardware during startup and provides runtime services for the operating system via the Power-On Self-Test (POST) process. BIOS has largely been replaced by UEFI on modern systems.
Boot Order
The sequence in which a computer's BIOS or UEFI firmware attempts to load an operating system from available storage devices and interfaces.
BIOS Password
A password configured in BIOS settings to prevent unauthorized users from accessing or modifying system firmware configurations.
Vulnerability
A weakness in a system, application, or process that can be exploited by a threat actor.
Access Control
A security mechanism that restricts access to resources based on policies, roles, or identity.

Topics

Bios Firmware Security System Hardening Boot Security Endpoint Security Access Control

Transcript

Why We Lock Down the BIOS

One of the threats to our systems would be if somebody got into the BIOS and started making changes to the settings on the BIOS. So one thing we'll want to do is lock down that BIOS. We would set up some sort of BIOS password to lock that down.

What the BIOS Does

The BIOS stands for basic input output system, and what it is is it will do some initial configurations of the computer.

The operating system is on some sort of storage, and that operating system needs to be loaded onto the RAM and processed by the CPU. But where does it find this operating system? How does it access the operating system? How does it start knowing even that basic how to access it? Well, one of the answers to that is the BIOS. The BIOS gets an initial set of instructions that tells the computer how to start up and how to start working. What happens is it gets loaded into RAM first, and then that gets processed by the CPU, and then it loads in the operating system from storage. So that is the basic input output system.

Settings and the Boot Order

The BIOS has a lot of different settings, settings like your boot order and what it should use to boot up. Some of these settings can be sensitive. For instance, with the boot order, if I wanted to change the boot order and make it so that way I can boot to USB and bypass all the security measures, I could do that by just getting into the BIOS, changing the boot order, and then booting up to that USB.

Setting the BIOS Password

So what I want to do is lock down these BIOS settings. The way to do that is that there is a BIOS password. The BIOS password is something that, if you boot up into BIOS and then you go through the configurations of it, one of the configurations is a password. So then what you would do is you would set the password on BIOS, so no one could boot into those BIOS settings.

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