What is a Software Bill of Materials ( SBOM)?

What is an SBOM? An SBOM (Software Bill of Materials) is a comprehensive inventory of all the components that make up a piece of software. It details every library, package, module and piece of code that was used to build the software, including open-source, third-party and proprietary elements. The SBOM enables organizations to track, manage, audit, secure and govern their applications, while ensuring compliance with regulatory requirements. In May 2021, the importance of the SBOM was emphasized in the US government’s Executive Order on Improving the Nation’s Cybersecurity.

Why Is It Important to Have an SBOM?

As software becomes increasingly complex and reliant on open-source components, it is important to have a clear and transparent view of all the elements that constitute your application. With an SBOM, AppSec, security and engineering teams can understand and secure software products more effectively. An SBOM provides value for:

• Security - If a zero-day vulnerability is publicly disclosed, the SBOM allows teams to quickly identify whether their software contains the vulnerable package version in their application environment. In addition, an SBOM helps organizations assess and manage other risks associated with the software components, such as operational risks or the potential for future vulnerabilities.

For example, in case of vulnerabilities like Log4j or XZ Utils, an SBOM allows teams to determine if the exploitable packages exist in the enterprise codebase.

• Compliance - Beyond security, software often needs to comply with various licensing agreements and regulatory standards, such as the executive order mentioned above. An SBOM helps in ensuring that all components meet the necessary compliance requirements, avoiding legal issues and penalties.
• Engineering - From a product point of view, an SBOM simplifies the process of managing and updating software components. With a detailed inventory, development teams can make informed decisions about upgrading components or replacing those that are no longer supported or secure. This proactive approach to software management helps maintain the longevity and integrity of applications.
• Customers - Finally, an SBOM provides transparency for customers and users into the software they are using or purchasing, building trust in the software provider and allowing them to use the SBOM for securing their application environment, now that the software they are sold will be running in their environment.

What are the Key Elements of an SBOM?

A software bill of materials provides visibility into the software’s components. This is because it comprises the following elements: 

• Component Details - The names, versions and identifiers (such as package names or hashes) of all software components. This helps in identifying specific elements that might be vulnerable or outdated.
• Licenses - The licenses under which each component is made available. This ensures legal compliance and allows managing violations and intellectual property rights issues.
• Sources - Where each component comes from, including the supply chain relationships. This provides insight into the trustworthiness and security of the supply channels.
• Vulnerabilities - Some SBOMs include information on known vulnerabilities associated with the components at the time of the SBOM's creation. This can aid in proactive security management.
• Dependencies - Detailed information about the dependencies of each component, including hierarchical relationships. This helps in understanding the potential impact of a vulnerability or issue within one component on the rest of the system.
• Build and Compilation Information - Details on how components were compiled or built, including the compilers or environments used. This aids in reproducing builds and understanding potential environmental vulnerabilities.
• Patch and Version History - Information on the version history and applied patches of components. This helps in tracking the update and maintenance history, assessing the impact of vulnerability management.
• Contact Information - Contact information for the person or team responsible for each component’s maintenance. This facilitates communication for reporting vulnerabilities or seeking clarifications.
• Security and Compliance Attestations - Certifications related to security standards compliance (e.g., ISO/IEC standards) or industry-specific regulations.
• Cryptographic Signatures - Cryptographic signatures for the SBOM itself. This helps in verifying that the SBOM has not been tampered with and comes from a trusted source.

Benefits of an SBOM

Having an SBOM means enterprises enjoy security, compliance and operational advantages:

• Enhanced Vulnerability Management - An SBOM provides a clear view of every component within a software application, making it easier to identify and address vulnerabilities. When a new vulnerability is discovered, organizations can quickly determine whether their applications are affected and prioritize remediation efforts accordingly. This proactive approach t significantly reduces the risk of security breaches.
• Improved Compliance and Risk Management - Industries like finance, healthcare and critical infrastructure are subject to regulatory requirements that mandate transparency about the software components used in operations. An SBOM documents the use of components that may be subject to licensing or regulatory scrutiny, enabling enterprises to manage legal and operational risks more effectively.
• Facilitated Software Supply Chain Security - An SBOM offers visibility into the software supply chain, enabling organizations to assess the security posture of their suppliers and enhance overall supply chain security.
• Streamlined Patch Management - SBOMs simplify the process of patch management by providing a detailed inventory of software components. When updates or patches are released for these components, organizations can easily identify which applications are impacted and expedite the patching process.
• Enhanced Transparency and Trust - Providing an SBOM to customers and stakeholders provides insight into the software components they use, reassuring them of the commitment to security and compliance. This transparency builds long-term trust.
• Support for OSS Management - SBOMs track the usage of open-source licenses and ensure that obligations related to these licenses are met. In addition, SBOMs facilitate the identification of outdated or unsupported open-source components, enabling organizations to make informed decisions about replacing or updating them.

Challenges of Implementing an SBOM

Despite the benefits of an SBOM, generating and maintain an SBOM comes with its own set of challenges:

• Complexity and Scale - Modern software applications often consist of numerous components and dependencies, making it challenging to create, track and maintain a comprehensive SBOM.
• Dynamic Nature of Software - Software is constantly evolving, with frequent updates, patches and new releases. Keeping SBOMs up-to-date requires continuous monitoring and documentation of changes in software components, which can be resource-intensive and time-consuming.
• Lack of Standardization - Currently, there is no universally accepted standard format for SBOMs. This lack of standardization leads to variability in how organizations create, store and share SBOMs in SBOM tools. This makes it difficult to exchange information effectively across different stakeholders in the software supply chain.
• Limited Visibility into Supply Chains - Organizations often have limited visibility into third-party and open-source components. Obtaining SBOMs from upstream suppliers can be challenging, particularly for proprietary or closed-source software.
• Security and Privacy Concerns - SBOMs contain sensitive information about software components and their dependencies, raising security and privacy concerns. It is important to protect SBOM data from unauthorized access, tampering, or exploitation to prevent potential security breaches or intellectual property theft.
• Resource Constraints - Small and medium-sized organizations may lack the resources, expertise, or infrastructure needed to implement and maintain SBOMs effectively. 
• SBOM Operationalization - Ensuring the enterprise can use the SBOM to its full extent. This includes visibility into where all SBOMs, the ability to find SBOMs quickly in case of a zero-day disclosure, knowing how to look for vulnerable packages, finding running applications with vulnerabilities, and more.

Best Practices for Integrating Your SBOM Into the SDLC

Integrating your SBOM into the SDLC enables making informed decisions throughout the development process. Here are some best practices for doing so effectively:

1. Start Early. Integrate SBOM generation tools and practices from the initial stages of the development process. This ensures that all open-source components, proprietary code and third-party libraries are tracked from the get-go.
2. Automate SBOM creation with tools that automatically generate and update SBOMs as part of the build process. Automation minimizes human error and ensures the SBOM remains up-to-date as the project evolves.
3. Integrate with existing CI/CD pipelines. This enables continuous monitoring and management of software components, vulnerabilities and compliance issues as part of the development workflow.
4. Treat SBOMs as part of the software's source code, checking them into version control repositories. This approach ensures that every software build is accompanied by a corresponding SBOM, making it easier to track changes and dependencies over time.
5. Use the SBOM to regularly scan for vulnerabilities in components listed in the inventory. Tools like SCA can leverage the SBOM to identify and mitigate security risks effectively.
6. Ensure that the SBOM includes detailed licensing information for every component. This facilitates compliance with open-source licenses and prevents potential legal issues.
7. Evaluate the security practices of third-party vendors and open-source components, reducing the risk of supply chain attacks.
8. Make SBOMs accessible to all stakeholders, including development teams, security professionals and compliance officers. This transparency ensures that everyone involved has a comprehensive understanding of the software’s composition.
9. Foster a collaborative environment for remediation. Developers, security teams, and legal advisors should work together to review the SBOM and address issues promptly.
10. Continuous education and training can enhance the security and efficiency of the development process. Ensure that your development, security, and operations teams understand the importance of SBOMs and how to leverage them effectively. 

Create and Maintain and SBOM with Checkmarx SCA

Choose an SCA solution that provides SBOM functionality, analyzes SBOMs from other application providers, and analyzes SBOM data to identify and prioritize risks and provide remediation recommendations. Checkmarx SCA allows you to easily generate an SBOM of all your software components to understand your open source risk. Learn more by requesting a demo.