SBOM 101: A Complete Guide to Software Bill of Materials

Code reuse has become a foundational practice in modern software development.

Some estimates suggest that over 80% of developers today re-use existing code, rather than writing code from scratch, when building software applications.

This trend is largely due to the open-source movement, as one might call it. There exists a massive, ever-growing public repository of open-source libraries, frameworks, and components.

Companies have reported reductions of up to 40% in development costs, 30% in maintenance hours, and 50% in delivery times by reusing existing components.

But such rewards are invariably accompanied by risks as well. 

Key takeaways

• Most mobile apps unintentionally expose sensitive user data through SDKs, misused permissions, or hidden third-party calls.

• Traditional static or point-in-time audits often overlook dynamic risks, such as silent API calls or SDK behaviors, that occur at runtime.

• Appknox Privacy Shield maps your app’s privacy surface in real time—visually tracking where data flows, what SDKs do, and which permissions are actually used.

• Risky behaviors, such as data exfiltration to sanctioned geographies or the transfer of unencrypted PII, are flagged before release.

• Privacy Shield integrates with your CI/CD to stop builds with privacy violations, enabling privacy-by-design without slowing down delivery.

• Designed for developers, security teams, and compliance leaders, Privacy Shield transforms privacy into a scalable, continuous process, rather than a bottleneck.

Risks associated with open-source components in your code

One of the biggest risks is ‘dependency sprawl’.

According to the 2025 OSSRA by Black Duck, software applications today depend on an average of 911 open source software components. And this is not an isolated incident - a Capterra survey found that 94% of all companies use open source components in their code.

That means, under the hood, your software application is a complex web of intertwined dependencies. 

To quote Tim Mackey, “Modern software applications have a dependency problem”. 

Complex dependencies create a visibility problem, where developers can’t determine exactly what is in their code base. 

Why do teams face a visibility problem?

Most dev teams maintain little to no documentation about the components they import and use in their code. They don’t know:

• Who the developer or vendor is, 
• Who built the component, 
• If there are known vulnerabilities in the component, and 
• The information about licensing and version updates. 

Your engineering and security teams need visibility into the above. They should be aware of:

→ The third-party software components used in your application,

→ Their location within your codebase,

→ The dependencies of each component, and

→ The licensing information for each component.

The high level of dependency on these and the lack of visibility into nested and transitive dependencies between components can trigger a cascading reaction that can cause your entire application to fail. 

And that’s why you need a Software Bill of Materials or SBOM.

Think of it as the ingredient list of your application: it provides a comprehensive inventory of all third-party software components, including libraries, frameworks, APIs, and packages used in your application. 

What is an SBOM?

A Software Bill of Materials, or an SBOM, is a document that lists all the components, libraries, and dependencies between them for a software product. 

It provides your developers and security teams with a comprehensive and detailed inventory of all the elements used to build your software application, much like a bill of materials in traditional manufacturing, which lists all the parts and materials used to build a product.

At a glance, an SBOM provides the following:

• All third-party software components (open source, APIs, packages)
• Version numbers, source, and metadata
• Dependency relationships (including nested ones)
• Licensing and security status for each component.

How can an SBOM fortify your software supply chain?

SBOM gives greater visibility into your software components: the building blocks used in developing your enterprise applications, which may have vulnerabilities buried deep within your app portfolio, waiting to blow up. 

By building and maintaining an SBOM for your software applications, your development and security teams will have complete visibility into the inventory of components used, the dependencies between them, and information about their licensing status.

SBOM advantage: What you gain (and lose without it)

Why visibility from SBOM matters

(Example of a real-world incident)

Let’s understand this closely with an example.

👉🏼 Picture this: There is a news flash about a security exploit that targets a vulnerability in a popular open-source component. Let’s call it ‘component X’. Now this sets off alarm bells ringing across your engineering team for two reasons: 

1. You know you have extensively used and re-used component X across your enterprise application portfolio, and
2. You don’t know where and how many instances of component X exist in your code base. 

Additionally, there’s the dependency problem, which exacerbates the issue several times over. Several other components may depend on component X, and/or component X may be nested inside other components, resulting in transitive dependencies. 

So, the ‘blast radius’ of one vulnerability in just one compromised component could have your entire team digging through your code base, looking for the proverbial needle in a haystack. 

True story: <plug Log4J incident - you staying over at work during Christmas holidays>

In short, you cannot secure what you cannot see.

Checklist: Signs you need an SBOM

✅ Unsure which open-source components are in your codebase

✅ Struggling to update or remove outdated/vulnerable libraries

✅ Hard to demonstrate compliance to auditors

✅ Difficult to respond quickly to security alerts (e.g., Log4j)

✅ Need to build trust with customers and partners

Benefits of an SBOM

1. Get complete component visibility

Development teams for enterprise software applications can be large and spread across the globe. Enterprises may also outsource application development. 

In either case, with so many hands on deck, the number of third-party components and libraries being imported into your application can easily run into double or triple digits. 

Not knowing what components are making your application work can not only be a huge blind spot but also the recipe for the perfect security disaster. 

When you generate an SBOM, you can quickly zero in on the affected parts of your application and apply a security fix, when required.

An SBOM provides visibility into every component and third-party library, including nested components used in your application’s codebase.

2. Optimize software application management

An enterprise software application will have an intricate, complex web of dependencies between modules and components. 

Software vendors employ software architects to maintain the application schema, database schema, and other related structures, which helps them visualize the internal structures of a software application. 

However, surprisingly, development teams lack a streamlined method to track dependencies between software components and libraries that go into their applications. 

An SBOM helps DevOps teams track dependencies between components, monitor licenses, and update components as necessary. This enhances the security posture of your application and avoids compliance issues.

3. Building an incident response plan

An SBOM helps you trace the upstream origins of each software component or library used in your application. 

This helps you avoid components with known risks and proactively identify potential security vulnerabilities.

So instead of firefighting security threats, you can have an incident response plan in place ahead of time.

4. Improve your vulnerability assessment process

For a developer, fixing a known security vulnerability or responding effectively to a security incident assumes the highest precedence. After all, an organization’s reputation, its credibility, and the sensitive data of users could be at stake. 

By building and maintaining an inventory of components used in your application, the SBOM eliminates the guesswork and helps isolate vulnerabilities to specific components. You can adopt a laser-focused approach to addressing security issues, minimizing the fallout of a vulnerability, rather than fishing in the dark. 

5. Respond faster to security incidents

When responding to a security threat, time is of the essence. 

However, without a clear understanding of the application's composition and a comprehensive mapping of dependencies between all components, your security response would remain stuck at the drawing board. 

An SBOM provides your developers and security team with a clear picture they need to build and release a security update in the shortest time possible.

6. Increased transparency

An SBOM can also help you offer customers and partners transparency into the software components (open source or otherwise) that you have used to build your software application. 

Transparency about the components used and the exact nature of dependencies between different components in your application helps build trust with customers, partners, and other stakeholders regarding the security posture of your application.

7. Improved regulatory compliance

Navigating today’s regulatory landscape can feel overwhelming, especially as requirements tighten around software transparency and supply chain security. 

With an SBOM, you gain a clear, living inventory of every component within your mobile app—open-source, third-party, and proprietary alike.

This visibility makes it easy to demonstrate compliance with mandates such as the U.S. Executive Order on Cybersecurity, GDPR, and PCI DSS, all of which increasingly require proof of secure, well-documented software components. 

When a new vulnerability is disclosed, your SBOM lets you respond quickly and confidently, showing auditors you’re in control.

The result? Less paperwork, fewer surprises, and a smoother compliance journey for your team and your business.

8. Business continuity

Even in the face of a security incident, you need to maintain service delivery like it was ‘business as usual’, while simultaneously resolving the security vulnerability.

An SBOM isolates the source of the vulnerability to a specific component or library. This helps in two ways: 

1. You can resolve security incidents much faster by knowing which systems use the affected components, and
2. Your development team can pursue a targeted security patching strategy without affecting components/systems that were not compromised. 

While an SBOM helps you identify and isolate the compromised software components, a security update might only be a temporary fix.

For a lasting solution, your development team can rely on the SBOM to provide suggestions for component alternatives. 

Additionally, an SBOM tracks the end-of-life dates for components used in your application, helping you plan for a timely migration to alternative components without compromising service delivery or causing system outages. 

What should a comprehensive software bill of materials include?

When you generate a software bill of materials for your application, it should typically include the following elements: 

A list of all components and libraries used in the software product

The inventory of components gives developers and security teams a snapshot of all the building blocks their software application depends on, along with their version numbers, source code locations, and any relevant metadata.

Licensing and security status information for each component

For this, your SBOM tool should link to a public database (such as the NVD or GHSA) to check for reports on known vulnerabilities associated with the components used in your application; the final SBOM document should include this information.

Mapping of dependencies

The SBOM should map out the interdependencies between software components, including information about nested dependencies, i.e., components that are composed of other components. 

Snapshot of a comprehensive SBOM

Are there any SBOM standards to follow?

Yes, because SBOM implementation remains a challenge for most organizations due to the lack of standardization of SBOM formats. 

Following a universal SBOM standard facilitates the easy sharing of information between CI/CD systems, helping organizations ensure consistent, machine-readable documentation of software components and streamline vulnerability tracking, compliance, and risk management.

Types of SBOM standards

Today, the two most popular SBOM formats across the software industry are OWASP’s CycloneDX and the SPDX format by the Linux Foundation:

SPDX

Built by the Linux Foundation, you can use the SPDX SBOM format to scan your portfolio to check whether your organization meets the licensing requirements for the commercial use of libraries and components used in your applications. 

This helps your enterprise avoid the steep costs of licensing violations.

CycloneDX

CycloneDX is a lightweight and flexible SBOM standard developed by OWASP for supply chain component analysis, meant for developers, and generates an inventory of first and third-party components (libraries, containers, frameworks, etc.).

Enterprises and developers can create their own custom document formats that they deem best suited for their customers, provided they include all the necessary data fields to ensure compliance with an SBOM.

The most common SBOM standards at a glance

Federal SBOM requirements

The US government coordinated with the National Telecommunications and Information Administration (NTIA) to define the minimum SBOM requirements:

Data fields

To enable companies to accurately identify and manage all software components across the software supply chain, the SBOM needs to specify the following vital data about third-party software components:

• Component identifiers (name, supplier, version number)
• Dependency relationships between components

Automation support

As per the SBOM standards laid out by the NTIA, these are the three machine-readable SBOM formats that are accepted, since they can be auto-generated

• SPDX
• CycloneDX
• SWID
  
  

Practices and processes

Practices and processes are the operational details that must be included in any contract that asks for them. The key requirements for the practices and processes section include:

Frequency

NTIA recommends generating new SBOMs in the following scenarios:

• For each update to a software component or the release of a new version
• When you find an error or discover a new detail about any component that was not included in your initial documentation

Depth

As per NTIA standards, your SBOM must list all top-level software components and their transitive dependencies.

Distribution

SBOMs need to be:

• Delivered quickly, with each product instance, or made available on your website
• Easy to use, with access permissions

Access of control

If you have to limit access to your SBOM to specific customers or users, you should specify access control terms. You need to offer allowances for customers who want to integrate SBOM data into their security tools.

Accommodation of mistakes

While SBOMs improve software assurance and reduce software supply chain risk, they’re not perfect. Customers must be tolerant of occasional errors or unintentional omissions, while organizations must be diligent in fixing errors.

SBOM best practices checklist

So here’s a checklist of best practices to implement SBOM in your organization to achieve SBOM compliance:

✅Automate your SBOM generation

Manually updating and generating a new SBOM with each release can become a huge burden for your development team.

Using an automated SBOM generation solution ensures your supply chain security management stays on track while minimizing the risk of human error creeping in. 

✅Designate a standard format

Most SBOM generation and management tools come with pre-defined SBOM formats.

When you use a standardized SBOM format, 

1. You establish uniformity in cataloging component data, and
2. You bring about consistency in reporting on vulnerabilities and their impact on software applications. 

Using a popular SBOM format is especially beneficial if your organization is just getting started with SCA.

✅Establish a comprehensive inventory process

A robust software inventory process involves identifying the components and gathering additional information such as their origin, licensing terms, and known vulnerabilities:

1. Develop a systematic process for identifying, tracking, and documenting the software components used in your applications
2. Keep accurate records of component names, versions, and dependencies
3. Regularly review and update this inventory to ensure it aligns with your evolving software environment

This comprehensive approach gives your teams a holistic view of your software supply chain. It allows you to make informed decisions on vulnerabilities and how to address them.

✅Collaborate with vendors and developers

Building a better SBOM requires collaboration with software vendors and developers.

Foster open lines of communication with these key stakeholders to obtain accurate and up-to-date information about the components they provide. This collaboration ensures that you stay informed about vulnerabilities, patches, and updates related to software components used in your app portfolio. 

Besides, engaging with vendors and developers allows us to establish a feedback loop.

We can share our SBOMs with them to validate the accuracy of the information and receive updates on any changes or new vulnerabilities. This collaboration fosters transparency, trust, and a shared commitment to software security.

✅Leverage automation and tools

Automated SBOM tools act as reliable assistants that 

1. Swiftly analyze software dependencies, 
2. Identify third-party software components, and 
3. Generate SBOMs with speed and precision.

By automating the software composition analysis process, your development and security teams can focus their time and energy on addressing vulnerabilities and fortifying the defenses of your app portfolio.

Automation not only saves time but also reduces the risk of human error, making sure no potentially vulnerable components are overlooked. It streamlines the SBOM generation process and ensures consistency across different software projects within your enterprise portfolio.

Automate SBOM generation with Appknox

With Appknox's binary-based SBOM, you can tick all the boxes related to securing your application portfolio’s dependencies on software components.

Get access to accurate security insights with comprehensive reports and actionable insights that empower you to make data-driven decisions confidently. 

With a simple four-step process, Appknox’s SBOM generates software component analysis reports that give your development, DevOps, and security teams visibility into: 

1. Components used across your app portfolio, 
2. Component-level vulnerabilities, 
3. Their vulnerability status, and 
4. A corresponding risk score.

Discover how Appknox’s automated SBOM gives you a transparent, up-to-date inventory of every component in your mobile app, making it easier than ever to identify vulnerabilities, respond to new threats, and meet regulatory requirements with confidence.

See Appknox’s SBOM in action

Frequently Asked Questions (FAQs)

Who needs an SBOM?

An SBOM is a necessity for any development, security, or compliance team that relies on open-source or third-party code, particularly in regulated industries or for government contracts.

What’s the difference between manual and automated SBOM generation?

Manual SBOM: Labor-intensive, prone to errors, hard to update. 

The manual method involves manually cataloging all software components and their inter-component dependencies within an application. This process typically includes component discovery, documentation, dependency mapping, license compliance checks, and ongoing SBOM maintenance.

Automated SBOM: Uses SCA tools, rapid and accurate, and easily integrates with CI/CD.

This is a more streamlined approach using specialized SBOM tools. These tools scan the codebase, automatically build an inventory of all components, and identify all dependencies between them, significantly reducing effort and improving accuracy compared to manual methods.

What are the risks of not having an SBOM?

Without an SBOM, you risk a lack of visibility into third-party components, which increases the chance of undetected vulnerabilities and non-compliance with regulations.

Does an SBOM help with zero-day vulnerabilities?

Yes, it does. An SBOM enables teams to quickly trace components and apply patches, thereby significantly improving incident response time.

How does an SBOM help with compliance?

By providing ready documentation of all components and dependencies, an SBOM enables seamless regulatory audits and facilitates easy compliance management, thereby supporting a proactive approach to software supply chain management.

Why are SBOMs essential? What are its key benefits?

The following are the primary benefits of an SBOM:

1. Complete component visibility

• Instantly see every third-party library or component in use
• Zero in on what needs patching, updating, or reviewing

2. Optimized software management

• Track dependencies and licenses
• Simplify upgrades and plan for end-of-life

3. Enhanced incident response

• Trace every component’s origin
• Identify and isolate risky components before they cause harm

4. Improved vulnerability assessment

• Isolate vulnerabilities to specific components, not entire apps
• Proactively address risks rather than react after the fact

5. Accelerated security fixes

• Reduce response time when threats arise
• Enable targeted security updates

6. Greater transparency & trust

• Show customers and partners exactly what’s inside your software
• Build confidence in your security posture

7. Regulatory compliance

• Demonstrate alignment with U.S. Executive Orders, GDPR, PCI DSS, etc.
• Quickly respond to audit requests and legal requirements

8. Business continuity

• Isolate incidents, avoid downtime, and patch strategically
• Plan migrations before components reach end-of-life