Software Composition Analysis (SCA) is an automated process used in software development to identify, analyze, and manage open source components within an application. Modern software relies heavily on dependencies that include open source libraries and third-party libraries, making them part of a complex software supply chain. The software supply chain has become a prime target for attackers, as compromising a single component can affect thousands of downstream applications. 

This is why SCA has become an essential part of modern software security practices.  It is crucial to understand the security, licensing, and compliance risks associated with the use of these components. SCA tools scan codebases to detect vulnerabilities, outdated dependencies, and potential legal issues arising from open source license violations. By integrating SCA into the software development lifecycle (SDLC), development teams can proactively mitigate risks, ensure compliance with industry regulations, and enhance overall application security.

Let's explore the key elements of SCA:

Vulnerability detection (CVE)

SCA tools continuously scan for vulnerabilities in your dependencies. These vulnerabilities are identified by unique Common Vulnerabilities and Exposures (CVE) IDs and are stored in public databases like the National Vulnerability Database (NVD). When a vulnerability is detected, SCA tools provide detailed information about:

• The severity level (CVSS score)
• Affected versions
• Available patches or fixes
• Potential exploit scenarios
• Remediation steps

License compliance

SCA tools help manage the complex world of open source licensing by:

• Identifying all licenses in use
• Defining license policies
• Flagging incompatible licenses
• Maintaining license inventories
• Generating compliance reports for legal teams

Dependency management

This aspect involves:

• Comprehensive dependency trees to identify direct and transitive dependencies
• Suggesting version updates
• Monitoring dependency health and maintenance status

Software Bill of Materials (SBOM)

An SBOM is a formal, machine-readable inventory of software components and dependencies. It includes:

• Component names and versions
• Licensing information
• Component relationships and dependencies
• Origin and supplier information

Why is SCA a non-negotiable part of modern software development?

Software Composition Analysis (SCA) is critical in modern software development because it helps organizations identify and manage the risks associated with open source components, which make up the majority of today's applications. SCA's importance stems from several critical factors:

1. Risk management:
   • 80-90% of modern applications consist of open source code
   • Average time to detect a vulnerability is reduced from months to minutes
2. Compliance requirements:
   • Many regulations (HIPAA, PCI DSS) require dependency tracking
   • Executive Order 14028 mandates SBOM for federal suppliers
   • Industry standards increasingly require component transparency

With the increasing reliance on open source software, ensuring security, compliance, and risk mitigation has become a top priority for development teams. SCA provides automated scanning and analysis of third-party dependencies, ensuring that software remains secure, compliant, and resilient against cyber threats.

How does SCA scanning work? 

SCA works by analyzing software dependencies, including direct and transitive (indirect) dependencies, to identify known security vulnerabilities listed in public vulnerability databases like the Common Vulnerabilities and Exposures (CVE) database, the United States National Vulnerability Database (NVD), and proprietary security databases maintained by SCA vendors. 

When vulnerabilities are found, SCA tools provide actionable insights, such as recommended updates, patch availability, and severity ratings, helping developers remediate security issues efficiently. Additionally, SCA ensures license compliance by detecting open source licenses like GPL, MIT, Apache, and BSD, which can have legal implications if improperly used in proprietary software.

SCA operates through several mechanisms:

1. Discovery Phase:
   • Scans project manifests (package.json, pom.xml, requirements.txt)
   • Analyzes build configurations
   • Identifies binary and source code components
2. Analysis Phase:
   • Cross-references components with vulnerability databases
   • Checks license compliance
   • Validates version compatibility
   • Assesses component quality and maintenance status
3. Monitoring Phase:
   • Continuous scanning for new vulnerabilities
   • Real-time alerts for security issues
   • Update notifications
   • Dependency drift detection

What are the benefits of SCA?

SCA offers several critical benefits to software development, making it an indispensable tool for modern development teams. 

• Reduced Security Risks
• Development Efficiency
• Lower Costs
• Better Code Quality
• Legal Compliance
• Enhanced Trust

Reduced security risks

• Decreased vulnerability exposure, and exposure time
• Improved supply chain visibility

Development efficiency

• Faster component selection
• Automated updates
• Reduced manual security reviews

Lower costs

• Reduced incident response costs
• Lower maintenance overhead
• Better resource allocation

Legal compliance

SCA tools ensure that organizations comply with the various licenses of the open source components they use. By defining license policies, and identifying and cataloging these licenses, they help avoid legal risks associated with the misuse of open source software.

Effective risk management

SCA provides insights into the dependencies used within a project, enabling organizations to manage and mitigate risks effectively. This includes tracking deprecated or outdated libraries and suggesting safer, up-to-date alternatives.

Continuous quality assurance

Integration of SCA tools with Continuous Integration/Continuous Deployment (CI/CD) pipelines allows for continuous feedback on code quality. This integration helps proactively maintain high coding standards and minimizes the likelihood of introducing errors or vulnerabilities into the codebase.

Operational efficiency

SCA automates the identification and remediation of vulnerabilities in open source components, streamlining the management process. This automation leads to increased operational efficiency, allowing development teams to focus on other critical tasks.

Comprehensive dependency management

SCA provides a holistic view of all third-party code used within a project. This comprehensive view enables developers and managers to understand the associated risks and make informed decisions to enhance the security and reliability of their software.

SCA vs SAST vs DAST: What’s the difference?

Understanding the key differences between SCA, Static Application Security Testing (SAST), and Dynamic Application Security Testing (DAST) helps developers apply the right check at the right time to stop issues from reaching production.

1. SCA

SCA focuses specifically on the third-party, generally open source, components and dependencies that form the backbone of modern applications.

• What it analyzes: Open source libraries, identifying both direct dependencies (what you import) and transitive dependencies (what your imports rely on).
• When it fits: It's used during the Build and Review stages when dependencies are resolved and updated.
• How it works: It scans components and checks them against public databases like the national vulnerability database (NVD) for known vulnerabilities (CVEs).
• Developer Benefit: It provides the data needed to generate a Software Bill of Materials (SBOM), which is an inventory of all software components, essential for security audits and compliance. It also detects vulnerabilities at a stage before code may be released to the public.

2. Static Application Security Testing (SAST)

SAST analyzes the application's source code, byte code, or binary code without executing it, acting as a "white-box" test.

• What it analyzes: Your first-party code (the code you or a team member write) and AI-generated code.
• When it fits (Shift left): Primarily during the coding stage in your IDE and during pull request (PR) review.
• How it works: It inspects the structure of the code for logical and security weaknesses, such as insecure communication, weak cryptography, or buffer overflows, or injection flaws.
• Developer benefit: Provides real-time feedback in the IDE, enabling you to find and fix issues as you code when they are cheapest and easiest to resolve.

3. Dynamic Application Security Testing (DAST)

DAST performs an analysis of the application while it is running in a test environment, interacting with it from the outside like an attacker (a "black-box" test).

• What it analyzes: The exposed interfaces, HTTP requests, and responses of the running application.
• When it fits (shift right): Typically applied later in the pipeline, during testing, staging, or even in production environments.
• How it works: It simulates real-world attacks to find vulnerabilities that appear at runtime, such as server misconfigurations and errors in authentication or session management.
• Developer insight: It can confirm whether a vulnerability found by SAST is actually exploitable in a live environment, and find run-time flaws not detected by static code analysis.

What are the best practices of implementing SCA scanning?

1. Shift left: Integrate SCA into the developer workflow

The most crucial step is to run SCA scans as early as possible—ideally before code even leaves the developer's machine.

• Show dependency issues in the IDE: Integrate the SCA tool into developer's Integrated Development Environment (IDE) to show warnings about insecure or non-compliant dependencies as they are introduced. 
• Automate in the PR: Enforce an automated SCA scan as a required step in every pull request (PR). The SCA results should be clearly visible, flagging vulnerabilities and license issues before the code is merged.
• Enforce with quality gates: Use quality gates to automatically fail the build or prevent the merge of a PR if it introduces a dependency with a high-severity vulnerability (a known CVE) or a restrictive license. This ensures that bad dependencies never get merged into your main branch.

2. Go deep: Analyze all dependencies

Comprehensive coverage means checking every component, not just the ones you explicitly added.

• Scan transitive dependencies: Ensure your SCA tool checks not only your direct dependencies (the libraries you intentionally included) but also transitive dependencies (the libraries those libraries rely on). Transitive dependencies are often a source of hidden vulnerabilities and unexpected risk.
• Generate an SBOM: Automatically generate a Software Bill of Materials (SBOM) in a standard format (like CycloneDX or SPDX). This detailed, machine-readable inventory of all components is essential for security audits, legal compliance, and rapid response if a new vulnerability is discovered in a component you use.
• Integrate advanced SAST: Move beyond simply identifying known vulnerabilities. employ advanced SAST capabilities to trace how your custom code interacts with a vulnerable third-party library. This helps identify deeply hidden security flaws that might arise from the interaction between your code and the open source component.

3. Operationalize: Manage risk and compliance

SCA must be integrated into your governance and compliance strategy to provide long-term risk management.

• Define license policies: Clearly define and automate enforcement of your organization's acceptable open source license policies. The SCA tool should automatically flag incompatible or problematic licenses, simplifying the complex task of managing legal risk.
• Prioritize with context: Avoid alert fatigue by providing developers with actionable, curated information instead of raw CVE reports. Effective tools prioritize vulnerabilities by factors like severity (CVSS score) and exploitability, ensuring developers focus their limited time on the risks that truly matter.
• Integrate reporting: Automatically generate reports aligned with security and governance standards, such as those related to the NIST Secure Software Development Framework (SSDF). This simplifies regulatory adherence and provides management with clear visibility into supply chain risk.

Key features to look for in an SCA tool

An SCA tool is only as good as its ability to find and assess every part of your application's external code.

• Transitive dependency scanning: The tool must go beyond direct dependencies (the libraries you explicitly install) to scan transitive dependencies (the libraries those direct dependencies rely on). This is where many hidden security flaws reside.
• Broad ecosystem support: Look for coverage across all the programming languages and frameworks your team uses, including popular ecosystems like Java, JavaScript, Python, C#, Go, and more.
• Advanced vulnerability context: It should provide more than just a list of CVEs (Common Vulnerabilities and Exposures). The tool should offer crucial context, including the vulnerability's severity (CVSS score), exploitability information (like EPSS - Exploit Prediction Scoring System), details on affected versions, and information on available patches or fixes.
• Integration with DevOps platforms: Look for native integration with major DevOps platforms like GitHub, GitLab, and Azure DevOps to automate scans and display results directly on Pull Requests (PRs).
• Quality gate enforcement: The tool should be able to enforce policies by integrating with configurable quality gates that automatically fail the pipeline if a new dependency introduces critical security or licensing risks.
• Developer-first security: The SCA analysis should integrate with a Static Analysis Security Testing (SAST) solution. This provides a unified platform for analysis, eliminating the need to juggle multiple, disconnected tools.
• Automated SBOM generation: The tool should automatically generate a SBOM in standard formats (e.g., CycloneDX and SPDX). This is essential for transparency during security audits and meeting regulatory compliance requirements (like those mandated by the NIST Secure Software Development Framework).
• License compliance management: The tool must automatically identify the licenses of all dependencies and help ensure they comply with your organization's legal policies, flagging potentially incompatible or problematic licenses. This simplifies the complex task of managing open source legal risk.
• Prioritized remediation guidance: To fight alert fatigue, the SCA tool should offer intelligence that reduces noise, such as confirming whether a reported CVE actually affects a specific usage context or providing workarounds when a direct fix isn't immediately available.

Why SonarQube?

SonarQube takes a fundamentally better approach to software composition analysis by delivering it as an integrated piece of a unified platform, not as a standalone tool. SonarQube is the only integrated solution that delivers code quality, SAST, taint analysis, secrets detection, IaC scanning, and SCA (included in SonarQube Advanced Security) for your entire codebase—first-party, AI-generated, and open source—all within a single workflow. This integrated analysis is better because it eliminates tool sprawl and developer toil, allowing you to use advanced capabilities like advanced SAST to trace data flow deep into third-party dependencies, finding complex vulnerabilities that traditional SAST/SCA tools miss. By embedding all security checks directly into the IDE and CI/CD, SonarQube ensures security standards are enforced automatically at every step, empowering developers to fix issues fast and ship secure code confidently.