SBOMs: What’s Inside Your Software Is A Big Deal

Last time, we broke down why Zero Trust isn’t something you just buy off a shelf. This time, I want to cover something a little less conceptual and a lot more literal, knowing what’s inside the software you’re running.

That’s what a Software Bill of Materials (SBOM) is for, and if you haven’t come across the term yet, I’m sure you will soon. In many software supply chains, it’s evolved from a niche compliance detail to a genuine requirement.

What It Is

An SBOM is a complete, structured inventory of every component that makes up a piece of software, down to the individual libraries and dependencies. Think of it like an ingredients list. It’s not just this application performs x, y, z, but a literal list, such as the specific library and the specific version used by a specific dependency.

Why This Matters

Here’s an uncomfortable truth about modern software, almost nothing is built entirely from scratch anymore. A typical application might consist of predominately open-source and third-party components glued together with a relatively small amount of code a team wrote themselves.

The problem is that when a vulnerability gets disclosed in an open-source library, most organizations have no reliable way to answer a simple question, “is that library running anywhere in our system?” This question can take days or weeks to answer, if at all. Cyber teams will scramble, pinging their engineering team hoping someone remembered what dependencies they’d pulled in months ago. Unfortunately, attackers can move a lot faster than a scramble.

A handful of major supply chain incidents have made this gap impossible to ignore. When a widely-used component turns out to have a serious vulnerability, organizations that have an accurate SBOM can answer “are we affected” within minutes. The ones that don’t will be attempting to figure out what they are running while the vulnerability is already being exploited.

What’s Inside

For every component, a proper SBOM typically includes:

· What it is — The specific library, package or module.

· What version — The exact version number in use.

· Where it came from — The supplier or source of the component.

· What it depends on — The dependencies, which have their own dependencies.

· Licensing information — The terms that govern the use of the component.

Multiply that across every dependency, and the dependency-of-a-dependency chains, and a single application can have an SBOM listing hundreds or even thousands of components.

Why This Isn’t Just a Cyber Issue

SBOMs exist at an interesting intersection. Cyber teams need them to respond quickly to vulnerabilities, legal and compliance teams want them to manage license risk, and increasingly regulators and customers require them as a condition of doing business at all.

You can’t quickly assess a vulnerability or an incident if you don’t already know what’s running in your environment. SBOMs are increasingly becoming a standard part of software procurement; you can’t manage a supply chain risk you can’t see.

Where It Gets Hard

Generating an SBOM once isn’t the hard part, there are various tools that can scan a codebase and create one. The challenge is maintaining its accuracy. Software can change; new dependencies get added, versions get bumped and older components remain hidden when teams forget to remove them.

An SBOM that’s accurate on the day it’s generated and stale a month later isn’t much better than not having one, it just creates false confidence. The organizations getting real value out of this are the ones treating SBOM generation as a continuous part of their build pipeline, not a one-time compliance artifact.

Beyond Compliance

Even outside of a regulatory mandate, the underlying discipline is to know what’s running in your environment, down to the dependency level, and be able to answer “are we affected” the moment a vulnerability gets disclosed.

Thanks for joining me and stay tuned for the next article!

Next time we’ll pivot to something a little different: CIRCIA and what the shift toward mandatory incident reporting means for teams on the ground.