Software Bill of Materials (SBoM): A Comprehensive Guide

Software Bill of Materials (SBoM): A Comprehensive Guide

In the software development world, transparency is critical, not just in terms of code quality, but also for understanding the components that make up the software. Enter the Software Bill of Materials (SBOM) - a comprehensive record of the components in a piece of software. Let’s dive deep into understanding the SBOM, its importance, and how it can be beneficial for developers and users alike.

What is a Software Bill of Materials (SBOM)?

Much like a traditional Bill of Materials (BOM) used in manufacturing, which lists all the components and materials required to manufacture a product, a Software Bill of Materials (SBOM) is a comprehensive list detailing the components in a piece of software. It lists all elements, including but not limited to libraries, modules, frameworks, and other software components that are utilized in the application.

For instance, an application might have dependencies on libraries like lodash, express, or react.

More Information: NTIA’s SBOM Overview

Role of SBOM in Cybersecurity

The SBOM is an essential tool in the cybersecurity toolkit. It provides:

  • Supply Chain Transparency: As software becomes more complex, with components sourced from multiple suppliers, having an SBOM helps in ensuring transparency in the software supply chain.
  • Security and Vulnerability Management: With cyber threats evolving rapidly, it’s vital to understand which components are present in your software, especially if any of them have known vulnerabilities. An SBOM aids in identifying vulnerable components quickly, enabling timely patches or replacements.
  • License Compliance: Different software components come with varied licensing terms. An SBOM helps organizations ensure that they are not in violation of any licensing conditions, thus avoiding potential legal complications.
  • Incident Response: Enables faster reaction times if a component is found to be compromised.

Reference: NIST’s take on SBOM and Cybersecurity

Executive Order by President on SBOM

The importance of SBOMs was underscored by a US executive order issued in 2021. It stressed the necessity for better supply chain security. This order highlighted the importance of understanding and tracking software components, with the SBOM playing a pivotal role.

Further Reading: White House Executive Order

SBoM and the Software Supply Chain

The software supply chain, while distinct from an SBoM, stands as a pivotal approach to software management in the modern enterprise landscape. The software supply chain outlines the sequence of processes essential for delivering a software to production.
In a software supply chain, multiple components come from various sources. The SBOM ensures that each of these components is documented, thus aiding in:

  • Traceability: Identifying the origin of every component.
  • Accountability: Ensuring suppliers maintain security standards.
  • Risk Management: Assessing potential vulnerabilities.

Case Study: SolarWinds Attack

VEX and its Connection with SBoM

Vulnerability Exploitability (VEX) adds another layer to the SBoM by determining how exploitable a vulnerability in a component might be. While the SBoM lists the components, VEX provides a risk assessment for potential vulnerabilities.
SBOM might tell you that you’re using library X v1.2, VEX would inform you how critical an update to v1.3 might be based on exploitability metrics.

Deep Dive: VEX in Vulnerability Management

Recommended Approach to Building and Maintaining SBoM for an Enterprise

  1. Cataloging: Document every software component in use. Software analysis tools, such as software composition analysis (SCA) and binary composition analysis tools, can help augment the efforts of the development team in gathering and processing software dependencies.
  2. Regular Updates: As components get updated or changed, the SBOM should too.
  3. Integration with CI/CD: Automate the creation and maintenance of SBOMs within the DevOps pipeline.
  4. Collaboration: Engage with software suppliers for regular updates and patches.

Required Components of a Software Bill of Materials

An SBoM should adhere to a set framework for the identification, characterization, and maintenance of software dependencies.

A minimum list of required components provided by the National Telecommunications and Information Administration (NTIA) is as follows:

  • Supplier Name: The name of an entity that creates, defines, and identifies components.
  • Component Name: Designation assigned to a unit of software defined by the original supplier.
  • Version of the Component: Identifier used by the supplier to specify a change in software from a previously identified version.
  • Other Unique Identifiers: Other identifiers that are used to identify a component, or serve as a look-up key for relevant databases.
  • Dependency Relationship: Characterizing the relationship that an upstream component X is included in software Y.
  • Author of SBOM Data: The name of the entity that creates the SBOM data for this component.

The minimum elements are only what they are – minimal requirements. But to increase transparency and visibility, the NTIA recommends supporting broader use cases with more elements, and encourages organizations to ask suppliers for them. These include:

  • Additional data fields – hash of the component, lifecycle phase, other component relationships and license information
  • Cloud-based software and SaaS – creating and maintaining an SBOM for cloud providers, not just for on-premise software
  • Integrity and authenticity – mechanisms to verify the source of SBOM data, like digital signatures
  • Vulnerabilities – linking to external vulnerability data sources, instead of just relying on vulnerability data in the SBOM
  • Vulnerability and exploitability in dependencies – determining the impact of a vulnerability on a software component and communicating this information downstream through VEX
  • Legacy software and binary analysis – implementing binary analysis tools when SBOM data is not available, e.g. with legacy code
  • Implementation flexibility/uniformity – combining broader rules and procedures with leeway in specific areas

SBoM Lifecycle and Best Practices

Each and every SBoM is going to look somewhat different depending on the unique requirements of the organization. There are, however, some key SBoM lifecycle and best practices that can be shared among organizations to deliver the best application dependency management policy.

  1. Creation: Develop the SBOM during the initial software creation phase. Automate the creation of SBoM and integrate it with organization’s CI/CD Process
  2. Maintenance: Regularly update the SBOM throughout the software’s lifecycle.
  3. Sharing: Engage with your development team to incorporate extensive metadata about the software dependencies and share the SBoM with relevant stakeholders to maintain transparency.
  4. Archival: Store outdated SBOMs for reference.

Software Bill of Materials Use Case

Maintaining a thorough SBoM is no longer a luxury but a necessity in our complex business landscapes. Recognizing the various applications of SBoMs can help organizations grasp their intrinsic value as pivotal data management tools. Here are some prevalent SBoM use cases:

  1. Ensuring Compliance: The Presidential Executive Order on Improving the Nation’s Cybersecurity now mandates organizations selling to the federal government to sustain an SBoM. This shift underscores the U.S. government’s emphasis on transparent and meticulously managed SBoMs.
  2. Bolstering Security: A concerning reality of the current application landscape is the prevalence of vulnerabilities. 2022 “Software Vulnerability Snapshot,” report by the Synopsys Cybersecurity Research Center
    found that 95% of applications had at least one vulnerability or misconfiguration, and 25% of the vulnerabilities found were high or critical risk. An SBoM serves as a mechanism to monitor these vulnerabilities, empowering organizations to proactively fortify their security measures.
  3. Archival and Record Keeping: Whether it’s for assessing the technical facets of an application or pinpointing which applications utilize a particular package, preserving a historical archive of application dependencies is paramount.

Enhance your cybersecurity with Initializ: AI-Driven Unified DevSecOps Platform

Not just an SBoM: While Initializ provides a comprehensive SBOM, its integration with VEX offers a deeper dive into potential vulnerabilities, giving actionable insights and remediation methods.

Searchable SBoM and Vulnerability Dashboard: No more sifting through endless data. Initializ provides an easily searchable dashboard, ensuring that you can quickly identify and act on potential issues.

Holistic Approach: Initializ takes software security to the next level, ensuring that your software supply chain remains robust and secure.

Platform Overview: Initializ - AI-Driven Unified DevSecOps Platform

In conclusion, SBoMs, combined with tools like VEX and platforms like Initializ, are instrumental in bolstering cybersecurity in today’s ever-evolving digital landscape. Embracing these tools and best practices ensures not only a safer software environment but also a more accountable and transparent software supply chain.