SAST, DAST, and SCA

Amit SangwanAmit Sangwan
5 min read

What Are SAST, DAST, and SCA?

TypeFull FormWhat It Does
SASTStatic Application Security TestingScans your source code or binaries for security flaws before the app runs
DASTDynamic Application Security TestingTests the running application (usually in staging) for real vulnerabilities
SCASoftware Composition AnalysisScans dependencies (open source libraries) for known vulnerabilities (CVEs)

NOTE:: CVE, short for Common Vulnerabilities and Exposures, is a public catalog of known cybersecurity vulnerabilities and exposures.

Advantages of SAST: 
Removes the need for manual checks, checking hundreds and thousands of lines of application source code on the flyShift left – identify defects in the codebase early in the SDLC and reduce fixing cost

Disadvantage of SAST: 
Requires access to source code and underlying framework, not suitable for COTS customization or outsourced developmentUnable to identify run time and environment-related issues – hard to determine the actual risks of security flaws and meaningful remediation

SAST – Think: “White-box” code review

  • Goal: Identify issues like SQL Injection, XSS (Cross-site scripting), insecure crypto, hardcoded secrets

  • When: Early (during coding/commit/build)

  • Scope: Custom application code

  • Pros: Fast feedback, shift-left, no need to run app

  • Cons: False positives, no runtime context

  • Tools: SonarQube

DAST – Think: “Black-box” penetration testing

  • Goal: Find exploitable vulnerabilities in the deployed app

  • When: After deployment to test/staging

  • Scope: HTTP endpoints, UI interactions

  • Pros: Real-world vulnerability detection

  • Cons: No code visibility, can miss logic flaws, slow

  • Tools: OWASP ZAP, Burp Suite (Pro) etc.

SCA – Think: “Dependency health checker”

  • Goal: Find CVEs in your third-party packages (NPM, Maven, pip, etc.)

  • When: During build (or even pre-commit)

  • Scope: Dependency manifests like package.json, pom.xml, requirements.txt

  • Pros: Fast, covers (Open Source Softwares) OSS risks, license checking

  • Cons: May miss deeply nested/transitive issues

Security Development Life Cycle (SecSDLC or SDL):
An extension of SDLC that integrates security practices throughout every phase to build software that is secure by design, minimizing vulnerabilities and risks.

Phases Comparison Table

SDLC PhasePurposeSecSDLC PhasePurpose
RequirementsGather functional requirementsSecurity RequirementsDefine security needs & compliance
DesignCreate software architectureThreat Modeling & Secure DesignIdentify threats, design secure system
ImplementationCode developmentSecure Coding & SAST (Snyk and sonarqube)Write secure code, perform static scans
TestingFunctional & integration testingSecurity Testing (DAST, Pen Test) (OWASP ZAP, Burp Suite)Dynamic scanning & vulnerability testing
DeploymentRelease to productionSecure Deployment & ConfigurationApply secure configs, scan IaC & containers
MaintenanceBug fixes & updatesContinuous Monitoring & Patch ManagementMonitor security posture & patch vulnerabilities

How to Embed SAST, SCA, and DAST into CI/CD

A[Code Commit] --> B[SAST & SCA Scans ]
B --> C[Build & Run Unit Tests]

C --> D[Deploy to Staging]

D --> E[DAST Scan (Dynamic Application Testing)]

E --> F[Security Gate Check (Policies, CVE Threshold, License Check)]

F --> G[Deploy to Production]

DevSecOps Pipeline Security Steps

StepStageDescription & Tools
ACode CommitCode pushed triggers automated scans.
BSAST & SCAStatic code and dependency scans. Tools: Snyk, Checkov, Trivy
CBuild & Unit TestsCompile code and run unit tests.
DDeploy to StagingDeploy app to staging for further testing.
EDAST ScanDynamic scans for runtime vulnerabilities. Tools: OWASP ZAP, Burp Suite
FSecurity GateEnforce security policies; block risky deployments.

Some Other Tools:

Snyk

  • NOT a pure SAST or DAST tool, but a Developer-first Security Platform.

  • At its core, Snyk is an SCA tool, but it has expanded into a DevSecOps platform by offering::

    • SCA (Software Composition Analysis) → scans open-source dependencies (like in package.json, pom.xml, etc.)

    • Container security (Docker image scanning)

    • IaC ( Infrastructure as Code ) scanning (Terraform, Kubernetes YAMLs)

    • Partial SAST Capabilities (with Snyk Code)

Zscaler – Cloud Security Platform (Zero Trust)

  • A cloud-based secure gateway that protects users and workloads on the internet and internal apps.

  • When it's used:
    In network-level security, protecting users, endpoints, and cloud environments.

    What it does:

    • Enforces Zero Trust Access (ZTNA)

    • Protects users from malware, phishing, malicious content

    • Secures outbound internet access (SWG, Cloud Firewall)

    • DLP (Data Loss Prevention)

Benefits:

  • Prevents data breaches and malware

  • Secures remote access without a VPN

  • Ensures least privilege access

Okta – Identity & Access Management (IAM)

  • A secure identity provider that manages authentication and authorization across apps and APIs.

  • When it's used:
    Across the entire SDLC — both during development (auth integration) and production (access enforcement).

  • What it offers:

    • OAuth2.0, OpenID Connect (OIDC)

    • SSO (Single Sign-On)

    • MFA (Multi-Factor Authentication)

    • RBAC (Role-Based Access Control)

Benefits:

  • Prevents account takeovers

  • Enforces secure login policies

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Written by

Amit Sangwan
Amit Sangwan

💼 Automation Engineer | AI Enthusiast | Tech Blogger Passionate about automation, AI agents, and testing. Exploring innovations in QA while sharing insights on technology and career growth. Always learning, always evolving. 🚀