A Software Bill of Materials (SBOM) is an official record containing the details and supply chain relationships of various components used in building your software. Simply put, an SBOM is to software what a list of ingredients is to a recipe. It lists components along with their versions and the licenses under which they're available.
The main idea for SBOMs is transparency. They enable whoever is using any software to be aware of the underlying components. Given that many software components are open-source and free, this kind of knowledge makes sure that any vulnerabilities in these components are not passed on without the user being unaware.
Let's suppose we have a simple JavaScript application:
const express = require('express');
const app = express();
app.get('/', (req, res) => res.send('Hello World!'));
app.listen(3000, () => console.log('Example app listening on port 3000!'));
In this case, our SBOM must list express as a dependency, and also all dependencies of express itself (and its dependencies' dependencies, and so on).
With a well-organized SBOM, you can easily recognize potential security threats and vulnerabilities during development, making patch management more effective. SBOMs can significantly help in improving license compliance. SBOMs could also be used to control and limit the use of components with unfavorable licenses or potential security vulnerabilities.
Additionally, they offer an opportunity to analyze the security risks dynamically and remediate the vulnerabilities, thus helping organizations meet compliance requirements and minimize the risk of security attacks.
The JavaScript Express app mentioned in the first chapter may have an express vulnerability that could lead to a security breach. An SBOM would provide info about the versions of express making remediation easier.
The first challenge comes with identifying every software component used in the application. While major parts can be noted easily, smaller components or libraries that are used less frequently can be overlooked. Some components may have been used in only a small part of the codebase, making them difficult to track.
Dependency management is an inherent problem with creating a complete and accurate SBOM. Dependencies can be nested several levels deep and may include many different components. Providing a holistic representation of these dependencies proves to be a real challenge.
// In JavaScript, you might need to use dependencies of your dependencies
var _ = require('lodash');
_.mixin(require('lodash-inflection'));
// The above code uses `lodash-inflection`, which is a dependency of Lodash.
// Your SBOM needs to account for both.
Standardization is another challenge. There's no common format used by all developers or organizations to build an SBOM. Different teams may have different needs and therefore require different information to be stored in an SBOM.
Given the dynamic nature of software development, ensuring the SBOM is up-to-date can be a demanding task. Whenever elements are added or removed, or versions are updated, the SBOM must reflect these changes accurately.
As the SBOM contains components that could be targeted by malicious entities, managing their vulnerabilities becomes a crucial part of SBOM management. This includes keeping track of patches, updates, and security news related to all the components.
Another challenge is measuring the impact of a change in a component on the larger software application. If a component is updated or a vulnerability is discovered, it's important to understand which parts of the application might be affected.
Automate Generation: SBOM generation should be as automated as possible. There are tools available that can automatically generate SBOMs like SPDX, CycloneDX, etc.
Use Standard Formats: Using a standard format such as SPDX allows other teams or organizations to understand the SBOM easily.
Continuous SBOM updates: With the continuous updates in software components, it's important to make SBOM updates an integral part of your software development lifecycle (SDLC).
Integrate with your Software Development Process: Make the process of maintaining and updating the SBOM a part of the software development process.
Centralized SBOM management: With a centralized repository, it can be easier to generate, view and maintain SBOMs. This can also enable security teams to do company-wide analysis for risk and vulnerability management.
Here is a list of tools used for generating SBOMs:
CycloneDX: It's an open-source project designed to create lightweight software bill-of-material (SBOM). It supports many languages and formats like JSON, XML, and Protobuf.
OWASP Dependency-Track: An open-source project that can generate SBOMs. It provides comprehensive analysis and makes the task of creating & maintaining SBOM more manageable.
SPDX (Software Package Data Exchange): This is a standard format for communicating the components, licenses, and copyrights associated with software packages.
Syft: A CLI tool and library for generating a Software Bill of Materials from container images and filesystems.
Remember to choose a tool that is suitable for your specific needs and fits well with your existing systems and processes.
In conclusion, SBOMs are crucial in modern software development and security. Given the growing number of components in software and constant updates, it can be complex to generate and manage SBOMs. But, with automated tools and by integrating SBOM management in SDLC, these challenges can be mitigated.
