What is a Software Bill of Materials (SBOM)?

An SBOM is a comprehensive list of all the software components, dependencies, and metadata associated with an application. The SBOM functions as the inventory of all the building blocks that make up a software product. With it, organizations can better understand, manage, and secure their applications.

The need for SBOMs is driven by several factors that include:

• Ensuring software transparency
• Managing open-source software and third-party dependencies
• Identifying and mitigating security vulnerabilities
• Complying with legal and regulatory requirements

The Executive Order on Improving the Nation's Cybersecurity was issued by the US government in May 2021, and it highlighted the importance of SBOMs in enhancing the security of the software supply chain.

The SBOM as an inventory

An SBOM contains an inventory of software components and dependencies. Modern software applications often leverage third-party libraries and frameworks. Many of these dependencies have their own dependencies on other components. The result is a complex nesting of interconnected components. A clear understanding of these dependencies is critical for organizations. An SBOM helps to provide visibility into these relationships and how an application is composed, enabling organizations to better manage their software supply chain.

Included with this inventory is information about component origins and licenses. By understanding the source and licensing of each component, an organization can ensure that the use of these components complies with legal requirements and licensing terms. The SBOM allows organizations to evaluate potential risks from included components, such as using components from an untrusted source or violating license terms.

Using SBOMs to check against known vulnerabilities

An SBOM also plays a vital role in identifying and mitigating security vulnerabilities. With an inventory of components and dependencies, an organization can systematically check the inventory against databases of known vulnerabilities (such as the Common Vulnerabilities and Exposures database). Security teams can proactively identify and address potential threats in software application dependencies before attackers can exploit them.

SBOM formats and standards

Several formats and standards have emerged for creating and sharing SBOMs. Standardized formats facilitate the sharing of SBOM data across the software supply chain, promoting transparency and collaboration among different stakeholders. Well-known formats include:

• Software Package Data Exchange (SPDX)
• CycloneDX
• Software Identification Tags (SWID)

These formats offer varying levels of detail for different software ecosystems, allowing organizations to choose the format that best fits their needs.

The impact of cloud-native applications on SBOMs

Cloud-native applications have added to the complexity of software ecosystems. Because they are distributed, often depend on pre-built container images, and may be composed of hundreds or thousands of microservices — each with their own components and dependencies — the task of ensuring software supply chain security is daunting. If not properly managed, these applications run the risk of introducing security vulnerabilities.

With this backdrop, the critical role that SBOMs play in ensuring the security of cloud-native applications is clear. By providing a comprehensive inventory of software components that can be checked systematically for potential vulnerabilities, SBOMs enable organizations to effectively manage and secure their applications in the cloud.

Benefits of implementing SBOMs

Implementing SBOMs offers several benefits for organizations, including:

• Improved security posture: SBOMs enable organizations to identify and address potential security risks more effectively.
• Streamlined vulnerability management: Organizations can prioritize and remediate vulnerabilities more efficiently.
• Enhanced collaboration among teams:  By providing a shared understanding of an application’s components and their associated risks, SBOMs help different teams within an organization — such as development, security, and legal — collaborate more effectively.
• Facilitated software audits and compliance checks: Organizations can more easily demonstrate compliance with legal and regulatory requirements. They can also perform internal software audits to ensure the security and quality of their applications.

Challenges in adopting SBOMs

Although the benefits of SBOMs are clear, organizations may face several challenges when incorporating them into their software development life cycle:

• Integration with existing tools and workflows: Organizations must be strategic and consistent about integrating SBOM generation and management into their existing development and security processes. This can negatively impact development velocity.
• Ensuring accuracy and up-to-date information: Maintaining accurate and current SBOMs — especially in the case of applications that update or change frequently — can be time-consuming and resource-intensive.
• Addressing privacy and intellectual property concerns: Sharing SBOMs with external stakeholders may raise concerns within an organization about disclosing proprietary or sensitive information. Organizations need to find a balance between security and transparency.
• Encouraging adoption across the software supply chain: For this to be truly effective, all parties in the software supply chain must adopt and share SBOMs. Moving in this direction requires collaboration, standardization, and a commitment to transparency among all stakeholders.

Integrating SBOMs with Vulnerability Management Tools

To further enhance an organization’s security posture, SBOMs can be integrated with vulnerability management tools. For example, application or container scanning tools can use the information provided in an SBOM to scan for known vulnerabilities and threats. Automated security tools can routinely check SBOM inventories against a CVE database. Alerts can be generated when an organization’s use of a component violates license terms.

By incorporating SBOM data into vulnerability management and compliance audit processes, organizations can better prioritize their efforts and address risks in a more targeted and efficient manner.

CrowdStrike Falcon® Cloud Security includes Cloud Workload Protection, which provides complete visibility into workloads and containers. With pre-built scanning of container images, registries, libraries, CrowdStrike Falcon® Cloud Security brings early detection of threats, rapid alerting, and actionable insights for remediation.