What is a Software Bill of Materials (SBOM)?
A SBOM, or Software Bill of Materials, is a comprehensive inventory that lists all the software components and dependencies used in a particular application or system. It provides a complete and detailed breakdown of the various software elements, including open-source libraries, third-party components, and proprietary code.
The purpose of a SBOM is to enhance transparency and improve the security of software systems. By documenting the software components and their versions, it allows organizations to track and manage any vulnerabilities or known security issues associated with those components. This information is crucial for risk assessment, vulnerability management, and ensuring timely software updates and patches.
What can we find in a SBOM?
A Software Bill of Materials (SBOM), is composed of various elements that provide a comprehensive inventory of the software components used in a system. Here’s what you can typically find inside a SBOM:
– Software component information: This includes details about each software component, such as the name, version, and description. It helps identify and track the specific components used in the system.
– Component dependencies: A SBOM also outlines the dependencies between different software components. It identifies which components rely on others to function properly, ensuring a clear understanding of the relationships within the software ecosystem.
– Component origins: This section provides information about the origin of each component. It specifies whether a component is open source, proprietary, or a third-party library. Knowing the origin helps assess associated risks and understand any licensing requirements.
– Licensing information: A Software Bill of Materials includes the licensing details of the software components. It helps organizations ensure compliance with licensing obligations and understand any restrictions or obligations associated with specific components.
– Versioning and patch information: The Software Bills of Materials (SBOM) documents the specific versions of each component used in the system. It also includes information about available patches, updates, or security fixes for each component. This facilitates vulnerability management and ensures organizations stay up to date with security patches.
– Vulnerability information: An important aspect of an SBOM is capturing information about known vulnerabilities or security issues associated with each software component. This allows organizations to proactively address these vulnerabilities and assess potential risks.
– Metadata: Additional metadata may be included in an SBOM, such as the author, release date, or relevant URLs. This information provides context and aids in managing the software components effectively.
Extract of the Software Bill of Materials (SBOM) from Welma Yocto Linux, the off-the-shelf Linux distribution developed by The Embedded Kit
How to generate a Software Bill of Materials (SBOM)?
Creating a SBOM can be done through a combination of methods and tools, depending on the complexity of the software system. Here’s an overview of the process and different approaches that can be used.
Option 1: Automated scanning & SBOM tools
One common method is to utilize automated scanning tools specifically designed to generate SBOMs. These SBOM tools can analyze a software system, identify the components used, their versions, and associated vulnerabilities, and generate a SBOM report. These tools can often integrate with software repositories, package managers, or version control systems to streamline the process.
- CycloneDX: CycloneDX is an open standard for describing software bill of materials. It provides tools and libraries for generating and consuming SBOMs in various formats. The CycloneDX Maven Plugin and CycloneDX Gradle Plugin are popular tools for generating SBOMs from Java projects. You can find a list of SBOM tools in CycloneDX tool center.
- FOSSology: FOSSology is an open-source license compliance and scanning tool. It can analyze source code and binary packages to identify open-source components and generate SBOMs. FOSSology supports a wide range of programming languages and package formats.
- OWASP Dependency-Check: OWASP Dependency-Check is a software composition analysis tool that identifies known vulnerabilities in project dependencies. It supports multiple programming languages and package formats and can generate SBOMs in various formats, including CycloneDX.
- CVE Scan: CVE Scan is a Linux vulnerability scanner. It eliminates false positives by conducting a precise comparison with configuration and kernel details, with SBOM generation. With the help of annotation and whitelisting, the scanner continuously refines Linux Common Vulnerabilities and Exposures (CVE) results, which can be conveniently managed in your Git repository. By seamlessly integrating into the CI pipeline, CVE Scan simplifies daily vulnerability monitoring, providing a comprehensive solution for secure development environments. Additionally, it allows for easy exporting of analysis results in csv files and offers user-friendly dashboards for effortless reporting.
Option 2: Manual tracking
In some cases, manual tracking may be necessary, especially if automated SBOM tools are not suitable or available for the software system. This involves manually documenting the software components, their versions, dependencies, and other relevant information. It requires close collaboration with developers, reviewing documentation, and examining the source code to identify and track the components used.
Option 3: A combination of automated scanning tools & manual tracking
Often, a combination of automated scanning tools and manual tracking is employed. Automated tools can provide a starting point by quickly identifying the majority of components and their versions. Manual tracking can then be used to verify and supplement the information, especially for proprietary or custom-built components that may not be easily identified by automated tools.
Maintaining and updating SBOMs as the software evolves is crucial to ensure accurate and up-to-date documentation of the software components.
SBOM generation & SBOM management support secure software development
SBOMs can help you identify and manage security vulnerabilities, enhance supply chain security, support risk assessment, enable timely patching and updates, and facilitate compliance with security standards and regulations.
Identifying and managing vulnerabilities
Software Bills of Materials (SBOM) play a pivotal role in identifying and managing vulnerabilities in software applications. By providing a detailed list of all software components and their versions, developers can quickly assess if any known vulnerabilities are associated with the components. This enables proactive vulnerability management, allowing developers to prioritize and address potential security issues promptly.
Enhancing supply chain security
With the increasing complexity of software supply chains, it becomes crucial to ensure the security of the components integrated into an application. Software Bill of Materials enable visibility into the origin and integrity of software components, allowing developers to assess the trustworthiness of their suppliers. By verifying the authenticity and security of each component, organizations can mitigate the risks associated with compromised or malicious software.
Supporting risk assessments
SBOM generation provide valuable information for conducting risk assessments throughout the software development lifecycle. With a comprehensive understanding of the components used, developers can evaluate the potential impact of vulnerabilities or weaknesses in those components. This information aids in prioritizing security efforts, allocating resources effectively, and making informed decisions to mitigate risks.
Timely patching and updates
One of the critical aspects of secure development is ensuring that software applications are promptly patched and updated. SBOM management enable organizations to track the presence of vulnerabilities in third-party components. This information facilitates proactive monitoring and notification systems, ensuring that developers are aware of any security patches or updates released by component vendors. By integrating timely patches, organizations can significantly reduce the window of vulnerability and enhance the overall security posture of their software.
Facilitating compliance with security standards and regulations
Many industries have specific security standards and regulations that organizations must comply with. SBOM generation provide a valuable resource for mapping software components to these requirements. With SBOM management, developers can easily identify and demonstrate adherence to security standards, making compliance efforts more efficient and effective.
Check our article on the Cyber Resilience Act (CRA).
The adoption of Software Bills of Materials (SBOM) in secure software development practices offers numerous benefits. From vulnerability management to supply chain security, risk assessment, timely patching, and compliance support, SBOM generation enhance the overall security posture of software applications. By leveraging the detailed component information provided by SBOMs, software developers can make informed decisions, prioritize security efforts, and mitigate risks effectively. Embracing SBOM management as a standard practice contributes to the development of robust and secure software systems.
