What Is a Software Bill of Materials (SBOM)?

A software bill of materials (SBOM) is a document that provides a detailed inventory of the components and dependencies used in a software project. It also lists all of the libraries, frameworks, and their respective versions that are utilized within the software. When it comes to open source software (OSS), an SBOM can play a crucial role in ensuring transparency, security, and compliance.

Why Your Organization Should Use SBOMs

Using an SBOM – especially in OSS – enables an organization to gain visibility over components and dependencies, improve risk management, and much more. Below, we outline these benefits.

Component Visibility

OSS often incorporates various third-party components and dependencies. An SBOM allows developers and users to have clear visibility into all components used in the software. This includes open source libraries and frameworks, along with their specific versions. This visibility aids in understanding the software’s composition, identifying potential vulnerabilities, and tracking any licensing obligations associated with the open source components.

Vulnerability Management

Similar to any other software, OSS can be susceptible to security vulnerabilities. With an SBOM, organizations can track the versions of open source components and stay informed about any known vulnerabilities associated with those versions. This enables proactive vulnerability management by promptly applying patches or updates to mitigate and report any security concerns (see RFC8615). By having an up-to-date SBOM, organizations can assess the impact of vulnerabilities and take appropriate measures to secure their software.

Supply Chain Security

In recent years, software supply chain security has become a significant concern. An SBOM contributes to enhancing supply chain security by providing transparency into the components used in the software and their origins. It also allows organizations to assess the trustworthiness and security posture of the components they rely on. With an SBOM, organizations can identify and mitigate risks associated with compromised or malicious components, reducing the potential for software supply chain attacks.

Collaboration and Patch Management

OSS encourages collaboration and community involvement. An SBOM facilitates effective collaboration by providing a common understanding of the software’s components across different contributors and stakeholders. It assists in coordinating patch management efforts by clearly identifying the components that require updates or fixes. Collaboration within the open source community becomes more efficient when all participants can refer to a shared SBOM to address security vulnerabilities and other issues.

Regulatory Compliance

In some industries, regulatory frameworks require organizations to demonstrate transparency and control over the software components used in their applications or systems. An SBOM provides the necessary documentation to satisfy these compliance requirements. It allows organizations to demonstrate due diligence, traceability, and compliance with relevant regulations, especially when it comes to security and licensing aspects of OSS.

License Compliance

OSS is typically governed by specific licenses that dictate how the software can be used, modified, and distributed. An SBOM provides a comprehensive overview of all the open source components and their corresponding licenses. This helps organizations ensure compliance with the licensing terms of the OSS they are using. By understanding the licensing obligations, organizations can make informed decisions about the distribution and use of their software while avoiding any legal or compliance issues.

SBOM Requirements in Highly Regulated Industries

Several governments and organizations in highly regulated industries, such as banking and healthcare, are advocating for the use of SBOMs or considering making the use of an SBOM a requirement, either internally or for their suppliers .

Examples of Industries Using SBOMs

• Public Sector – The United States, European Union, United Kingdom, and Japan are among the many countries leveraging, regulating, or recommending the use of SBOMs.
• Technology – Large tech companies like Google, Microsoft, and IBM are leading the way by implementing SBOMs in their own software development processes, contributing to projects such as the Software Package Data Exchange (SPDX), OWASP, and an open sourcing an SBOM generation tool.
• Automotive – Several major automotive companies, such as Ford and General Motors, are implementing SBOMs and encouraging their suppliers to provide SBOMs for the components and software used in automotive systems.
• Healthcare – Medical device manufacturers in the U.S. market are now using SBOMs to comply with a 2022 Food and Drug Administration regulation.

Who Is Part of an SBOM Team?

Building an SBOM requires collaboration and involvement from various stakeholders throughout the software supply chain. By involving these stakeholders and fostering collaboration among them, organizations can build a robust and reliable SBOM that captures the necessary information about software components, enhances supply chain security, and facilitates risk management and compliance efforts.

Here are some key individuals or roles that should be involved in the process:

• Development team – The development team, including software engineers and developers, plays a crucial role in identifying and documenting the software components used in the project. They are responsible for providing accurate information about the dependencies, versions, and origins of the software components they utilize.
• Project managers – Project managers oversee the overall software development process and should be involved in building an SBOM. They can coordinate with the development team to ensure that the necessary information is gathered and documented in the SBOM. Project managers also play an important role in ensuring compliance with SBOM requirements and integrating it into the project workflow.
• Security team – The security team, including security analysts and specialists, is instrumental in assessing and managing security risks associated with software components. They can provide insights into vulnerabilities and known security issues related to the components listed in your SBOM. Their expertise helps identify potential security risks and prioritize remediation efforts.
• Procurement team – The procurement team, or individuals responsible for sourcing software components, plays a critical role in building an SBOM. They can provide information about the origin and licensing details of the components obtained from external sources. Collaborating with the procurement team ensures accurate tracking and verification of software components within the supply chain.
• Operations team – The operations team is often responsible for deploying and maintaining the software. When building an SBOM, they can contribute valuable information about the runtime environment, deployment configurations, and any additional software components introduced during the operational phase. Their insights ensure a comprehensive and up-to-date SBOM.
• Legal and compliance experts – Legal and compliance professionals are essential stakeholders in building an SBOM, particularly regarding licensing and intellectual property considerations. They can provide guidance on license compliance and ensure that your SBOM aligns with any legal requirements or restrictions associated with the software components.
• External vendors and partners – If the software project incorporates components or services from external vendors or partners, involving them in the SBOM process is crucial. They can provide necessary information about their offerings, including dependencies, versions, and vulnerabilities. Collaborating with external stakeholders helps ensure a comprehensive and accurate SBOM.

How to Build an SBOM

Organizations should aspire to build an SBOM that provides a comprehensive view of software components, their origins, dependencies, and associated security information. This enables better management of software supply chain risks and enhances overall software security.

Here are the key steps when building an SBOM:

• Identify and inventory components: Begin by identifying every software component that is used in your project, including both proprietary and open source components. Create an inventory list that includes information such as the name, version, and origin of each component.
• Determine component origins: For each component, determine its origin, whether it is proprietary, open source, or a combination of both. This step helps in assessing potential security vulnerabilities associated with different components.
• Document dependencies: Document the dependencies between components, including any libraries or frameworks that are used. This helps to understand the relationships between different components and ensures that all dependencies are accounted for.
• Gather metadata: Collect metadata for each component, such as license information, known vulnerabilities, and release dates. This information is crucial for tracking the security and compliance aspects of the software components.
• Automate SBOM generation: To streamline the process, consider automating the generation of SBOM using specialized tools. These tools can scan your software project, identify the components, and gather the necessary information automatically.
• Keep your SBOM up to date: As your software project evolves, it is essential to keep your SBOM up to date. Regularly review and update the inventory, component origins, dependencies, and metadata as changes occur.
• Share and utilize your SBOM: Share your SBOM with relevant stakeholders in your software supply chain, such as vendors, customers, and auditors. This promotes transparency, enables better risk assessment, and helps in identifying and addressing vulnerabilities.
• Monitor and manage vulnerabilities: Continuously monitor for new vulnerabilities and security updates related to the components in your SBOM. Stay informed about the latest security patches and address any vulnerabilities promptly to maintain the security of your software.

Seven Ways an SBOM Can Fail to Deliver

There are several ways an SBOM can fail or fall short of its intended purpose. Addressing these challenges and ensuring the accuracy, completeness, and currency of your SBOM can help mitigate the risk of failure.

Here are some common causes of failure that mirror the best practices for building an SBOM:

• Incomplete or inaccurate inventory: If your SBOM does not accurately capture all the software components used in a project or contains incomplete information, it can lead to blind spots and gaps in understanding the software supply chain. Missing or inaccurate inventory can result in overlooking vulnerabilities or dependencies, undermining the effectiveness of your SBOM.
• Lack of component visibility: If your SBOM fails to provide clear visibility into the origins, versions, and dependencies of software components, it becomes difficult to assess and manage associated risks effectively. Without comprehensive visibility, it becomes challenging to track vulnerabilities, identify patch updates, and ensure compliance with licensing requirements.
• Manual and outdated processes: Relying on manual processes to create and maintain an SBOM can lead to inefficiencies and errors. If your SBOM is not regularly updated to reflect changes in the software project, it quickly becomes outdated and loses its value as a reliable reference for security and compliance purposes.
• Insufficient metadata and context: An SBOM should provide more than just a list of software components – it should include relevant metadata such as licensing information, known vulnerabilities, and release dates. If this additional context is missing or incomplete, it hampers the ability to assess risks accurately and make informed decisions.
• Lack of stakeholder collaboration: Collaboration and information sharing among stakeholders in the software supply chain are vital for effective SBOM utilization. If there is a lack of cooperation or reluctance to share SBOM information, it becomes difficult to identify and address vulnerabilities collectively, compromising the overall security of the software.
• Limited tooling and automation: Manual creation and maintenance of an SBOM can be time-consuming and error-prone. Without proper tooling and automation, it becomes challenging to generate, update, and manage your SBOM efficiently. Lack of automation also may also lead to delays in identifying new vulnerabilities or dependencies.
• Inadequate vulnerability monitoring: An SBOM should be complemented by a robust vulnerability monitoring process. If there is a lack of regular monitoring for new vulnerabilities and security updates associated with the software components, potential risks may go unnoticed, leaving the software exposed to known vulnerabilities.

Summary

Overall, an SBOM is a valuable tool for managing the complexities of OSS. It promotes transparency, security, compliance, and collaboration within the open source ecosystem. By providing a detailed inventory of software components, their versions, and associated licensing information, an SBOM empowers organizations to make informed decisions, manage risks, and ensure the integrity and security of their software projects.

Resources

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• How to Prepare Your Apps for Regulated Markets