SAST vs. SCA testing: Strengths, Limitations, Implementation Best Practices & Integration

No matter how well developers follow the latest secure coding guidelines or how perfect their intentions are, some production code will almost always include at least one security issue. Developers are only human, and when faced with trying to balance the large and growing list of potential software vulnerabilities and the mounting pressures for faster release cycles, especially in more complex enterprise-level organizations, something has to give.

Let’s take a closer look at Static Application Security Testing (SAST) and Software Composition Analysis (SCA), the basic ideas behind these approaches, their advantages, and the differences between them. We’ll also cover how to leverage SAST and SCA and combine the two to release secure software and produce truly secure applications.

SAST vs. SCA: main differences

Let’s look at the differences in how each technology works to help determine which approach might be right for your organization.

SAST main features

• Analyzes code without execution. Conducts static analysis on source code, bytecode, or binaries—no running application is required. 

• Shifts security left in the SDLC. Can be deployed as early as the requirements, coding, or build phases—enabling developers to detect and fix vulnerabilities early. 

• Establishes internal understanding via code modeling. Builds structured representations like ASTs, Control Flow Graphs (CFGs), and Data Flow Graphs (DFGs) to analyze code structure, logic, and data paths. 

• Applies rule-based and pattern-matching analysis. Uses predefined rules—covering everything from insecure patterns to taint propagation—to flag potential vulnerabilities across code. 

• Supports multiple analysis techniques. Includes pattern matching, taint analysis, control/data flow checks, and semantic analysis to identify a broad spectrum of issues. 

• Scans extensively across the codebase. Can traverse dependencies, configuration files, logic, and SQL—even in large or obfuscated codebases—for comprehensive coverage. 

• Automated integration into development workflows. Easily hooks into IDEs (for real-time feedback) and CI/CD pipelines (for on-commit or build-time scanning), enabling continuous and automated security checks. 

• Generates actionable reports and remediation guidance. Provides developers with detailed output—flagging file/line locations, severity, context, and often suggestions for fixes. 

• Enhances compliance and secure-coding enforcement. Flags violations of standards such as OWASP Top-10, CWE/CERT policies, and helps organizations meet regulatory or internal security requirements. 

• Improves code quality and developer security awareness. Beyond security, it highlights code quality issues (e.g., improper error handling, dead code) and educates developers on secure coding practices.

SCA main features

• Identifies both direct and transitive open-source components. SCA tools scan codebases—including source code, package managers, containers, and binaries—to detect not only explicitly declared dependencies but also those included transitively. This visibility is crucial: around 80 % of vulnerabilities stem from transitive dependencies.

• Detects known security vulnerabilities and supports remediation. SCA systems cross-reference detected components against vulnerability databases (like NVD and vendor-maintained sources) and flag known CVEs. Ensures license compliance and legal risk mitigation

• By automatically identifying component licenses, SCA tools enable organizations to enforce license-policy compliance and reduce legal exposure.

• Generates Software Bill of Materials (SBOMs). SCA tools can create SBOMs—detailed inventories listing all components, their versions, sources, and relationships—facilitating transparency, auditing, and supply-chain risk management.

• Automates governance and policy enforcement across the SDLC. SCA integrates with CI/CD pipelines, enabling ongoing enforcement of security and license policies throughout development, build, and deployment stages.

• Supports continuous monitoring and supply-chain visibility. SCA continually monitors dependencies in all stages of the development lifecycle—catching new vulnerabilities or shifts in dependency exposure early.

• Leverages multiple scanning techniques for comprehensive detection. To reliably detect components—even in containers or undeclared files—SCA employs a blend of dependency-manifest parsing, file fingerprinting, signature matching, and binary analysis.

• Provides risk prioritization for effective remediation. Beyond detection, many SCA tools assess vulnerabilities and licensing concerns by severity or reachability—helping teams prioritize the most pressing risks.

• Enhances supply-chain security posture. By delivering deep visibility, automated compliance, and dynamic vulnerability tracking, SCA strengthens organizations against software supply-chain threats and fulfills regulatory expectations.

SAST tools & implementation tips

• Choose tools with high accuracy to minimize false positives. Pick SAST tools like Snyk Code, known for reliable detection, to avoid overwhelming your team with noise.

• Integrate seamlessly with developer workflows. Choose tools that work directly inside IDEs and repositories—this keeps feedback immediate and context-aware.

• Use change-based scanning to speed feedback. Only scan modified parts of the code to reduce scan times and preserve developer velocity.

• Embed SAST into CI/CD pipelines. Add SAST as a distinct CI/CD stage after build but before testing or deployment. Use lightweight scans on commits/PRs and deeper scans at night or prior to release.

• Define and enforce clear security thresholds. Block builds only on critical or high-severity issues to balance security with flow. Calibrate thresholds to avoid disruption.

• Continuously monitor policy effectiveness and fine-tune rules. Update rule sets regularly, suppress false positives, and optimize tool configurations for relevance and accuracy.

• Invest in educating developers on SAST findings. Teach teams how to interpret results, prioritize fixes, and adopt secure coding practices.

• Track security posture over time. Use metrics—like vulnerabilities per lines of code or remediation time—to monitor improvements and demonstrate ROI.

• Extend SAST beyond pre-release stages. Run periodic scans even in production or post-release to catch newly introduced issues.

SCA tools & implementation tips

• Integrate SCA early in the SDLC—even in IDEs or VCS. Enable real-time alerts for unsafe dependencies and enforce zero-trust for new components. 

• Capture both direct and transitive dependencies for full visibility. Since many vulnerabilities come through transitive libraries, ensure your tool uncovers these deep chains.

• Automate continuous scanning and sync with vulnerability databases. Maintain fresh results by performing frequent scans and updating from CVE/NVD feeds.

• Generate SBOMs with each build for transparency and compliance. SBOMs help track components and respond quickly to vulnerabilities or audits.

• Focus on actionable insights by prioritizing risk. Use severity, exploitability, and business impact to guide remediation rather than drowning in report noise.

• Adopt a policy-driven approach to open-source use. Define acceptable licenses, risk thresholds, and approval paths to guide developer behavior early.

• Automate remediation where possible. Incorporate features that patch vulnerable dependencies quickly and safely.

• Educate developers on open-source risks and interpretation. Awareness programs help ensure your team understands vulnerabilities, licensing issues, and best practices.

• Ensure comprehensive coverage of all projects and languages. Extend SCA to new codebases, languages, or technical areas that might otherwise be overlooked.

• Measure effectiveness and refine workflows. Track remediation speed, issue volume before deployment, and developer satisfaction, and then optimize based on these metrics.

How to combine SAST & SCA for application security effectively

• Adopt a layered security—or “shift-left” approach
  Use SAST early in the SDLC (such as during coding or build stages) to catch custom code flaws immediately, and SCA later (prior to release) to verify dependency security and license compliance.

• Integrate both tools into your CI/CD pipeline
  Embed SAST and SCA into PR checks, build phases, or nightly pipelines to ensure continuous, automated scanning for code-level and third-party component vulnerabilities.

• Use unified workflows or platforms when possible
  Leveraging tools that support both SAST and SCA centralizes results, simplifies remediation, and improves developer efficiency by reducing tool fragmentation.

• Enable consolidated visibility and prioritization
  Present SAST and SCA findings side-by-side—whether through dashboards or IDE plugins—so teams can triage issues holistically and prioritize fixes effectively. 

• Define clear gating policies and thresholds
  Establish criteria (e.g. block on high or critical findings) that trigger build or PR failures, while allowing low-severity issues through with notifications—maintaining balance between security and workflow momentum.

• Leverage consolidated results for compliance and audit readiness
  Use combined SAST and SCA reports to simplify adherence to regulations and maintain a full audit trail across both proprietary and third-party code.

• Continuously monitor and iterate across both tools
  Keep vulnerability databases current, update scanning rules, and monitor evolving risks in your dependencies and custom code. This ensures the approach stays proactive over time.

• Educate teams on workflow and shared responsibility
  Clarify roles: developers should fix SAST code issues early; security or DevSecOps should manage policy enforcement and SCA oversight; and DevOps should maintain pipeline tooling coordination.

A unified approach to application security

SAST and SCA are essential for a complete application security posture, but their unique functions mean they're most powerful when used together. While SAST focuses on securing your proprietary code from the inside, SCA protects your applications from vulnerabilities lurking in open source dependencies. They are not a matter of 'either/or' but a critical 'both/and' solution for any modern development team.

To truly secure your software supply chain, you must integrate both practices into your development lifecycle, shifting security to the left, where it's most effective. This layered approach allows you to catch and remediate issues early, maintain developer velocity, and build a robust defense against ever-evolving threats.

Want to discover how SAST and DAST can help your team catch vulnerabilities early and stay secure while you innovate? Explore Snyk's guide today.