Key Categories and Tools for SDLC Security

We’re all familiar with the classic Software Development Life Cycle (SDLC) diagram, which over time, evolved into the DevSecOps infinity loop as organizations have increasingly focused on SDLC security.

Today, this more widely accepted diagram illustrates a critical shift in how we approach security as a first-class citizen embedded within every phase of the development lifecycle. 



What is SDLC Security?

SDLC security is a framework for continuous testing and analysis of code and the code pipeline to identify and resolve vulnerabilities before they reach production.

This evolution reflects the essence of a truly secure SDLC, where security is not an afterthought but a native, continuous part of each stage. The commonly accepted stages of the SDLC include:

1. Planning and Requirements Gathering

2. Implementation (the actual Coding)

3. Build & Integration (CI/CD, Testing)

4. Testing

5. Deployment

6. Management & Maintenance (Post-deployment monitoring & technical debt management)

By integrating security concepts from planning through to maintenance, a secure SDLC framework equips teams to proactively identify and mitigate vulnerabilities, ensuring that security is as integral to development as coding itself.

In this post, we’ll break down each SDLC phase to see how security tools, integrations, and best practices can be woven into the lifecycle, creating a resilient foundation for secure software delivery.

Why is SDLC security so important?

As security threats evolve, securing applications across every phase of the SDLC has never been more essential.

SDLC security is not just about final-stage testing, as was once the common practice. Today, a secure SDLC involves embedding security measures throughout the entire lifecycle, while it’s still possible to mitigate risks and catch them early before they become full-fledged vulnerabilities. 

This cultural shift not only drives down the cost of fixing vulnerabilities by catching them earlier but also fosters collaboration among development, security, and operations teams.

DevSecOps has transformed security from a siloed responsibility into a shared mission across the entire engineering team, promoting a continuous feedback loop that ensures security is integral from the very first line of code to deployment and beyond.

By breaking down each SDLC phase, this guide shows exactly how security culture, tools and practices align with DevSecOps principles for each category.

Breaking down the SDLC Security Categories and Tools

In this guide, we’ll break down security practices, tools, and vulnerabilities associated with each SDLC phase, ensuring that every step— from planning to maintenance— keeps security at the forefront.

We’ll take a practical approach to mapping security directly to each phase of the SDLC, illustrating how the DevSecOps mindset reshapes the way we build and protect software.

With the “shift-left” philosophy, security is no longer confined to late-stage testing but is embedded early in the development process—making security checks as routine as coding itself. 

Planning and Requirements Gathering

Traditional SDLC In a traditional SDLC, this phase is mainly focused on defining project requirements, design principles and planning resources, often overlooking security concerns. Risks and vulnerabilities are rarely discussed here, which can lead to critical gaps in the later stages.

Secure SDLC The planning phase includes a proactive assessment of security requirements. Security teams often work alongside developers to establish threat models, compliance requirements, and security benchmarks, setting a strong foundation for secure design.

Tooling and Techniques

• Security Inclusion: Secure SDLC includes threat modeling and risk assessments right from the start.

• Tools: Microsoft Threat Modeling Tool, OWASP Threat Dragon for early risk identification and compliance checks.

Implementation (AKA Coding)

Traditional SDLC In a traditional approach, developers focus on writing code, but security practices are limited, if present at all. Vulnerabilities are often discovered much later in testing or even after deployment, resulting in costly fixes.

Secure SDLC Developers follow secure coding guidelines and use automated tools to catch vulnerabilities as they write code––from publicly known vulnerabilities in CVE registries, through common mistakes and misconfigurations like hard-coded secrets or bad security hygiene.

Security reviews and tools for software composition analysis (SCA) & static application security testing (SAST) are integrated into the development environment to identify issues early.

Tooling and Techniques

• Shift-Left Security: Secure SDLC integrates SCA, SAST and secret scanning directly in the IDE or CI/CD pipeline.

• Tools: Jit, Semgrep, SonarQube, GitHub CodeQL for SAST, and GitLeaks or GitGuardian for scanning secrets in real-time.

Build & Integration

Traditional SDLC In the build phase, code is compiled and dependencies are managed, but traditional SDLC often lacks security checks. This can lead to issues like using vulnerable third-party libraries, which may be identified only in production.

Secure SDLC Dependency checks, container scans, and CI/CD security are prioritized in the modern SDLC to catch issues before deployment. Tools for automated dependency scanning and secure CI/CD configurations ensure a security-focused build.

Tooling and Techniques

• Proactive Dependency Management: Secure SDLC implements dependency scanning and security checks in CI/CD.

• Tools: Dependency management scanners (there are many), code scanners like npm-audit or OSV scanner, and Jit for a unified platform for everything.

Testing

Traditional SDLC Traditionally, security testing occurs just before deployment, with dynamic and manual testing being limited in scope and frequency. Vulnerabilities caught at this stage often lead to delays and higher remediation costs.

Secure SDLC In addition to quality testing, include dynamic application security testing (DAST), penetration testing, and interactive application security testing (IAST), to uncover potential weaknesses. Continuous testing ensures vulnerabilities are identified and remediated as soon as they appear.

Tooling and Techniques

• Comprehensive Testing: Secure SDLC leverages DAST and IAST to cover a broad range of security tests.

• Tools: OWASP ZAP, Burp Suite for DAST, Metasploit for penetration testing, Contrast Security for IAST.

Deployment

Traditional SDLC In traditional SDLC, the deployment phase often lacks rigorous security checks, leading to misconfigurations and unsecured environments. Once in production, these vulnerabilities can be hard to fix without disrupting the application.

Secure SDLC When considering security, deployment includes security checks for infrastructure, access control and permissions, as well as common configurations. Infrastructure as Code (IaC), container security, configuration management and identity and access management tools help create hardened, secure environments.

Tooling and Techniques

• Configuration Hardening: Secure SDLC integrates security in deployment pipelines and infrastructure configuration.

• Tools: Terraform and OpenTofu with security modules, Trivy, Kubescape, Checkmarx KICS, Prowler.

Monitoring and Maintenance

Traditional SDLC After deployment, monitoring is typically limited to performance and availability. Security monitoring may only occur reactively, leaving applications vulnerable to emerging threats.

Secure SDLC An updated approach includes real-time and continuous security monitoring, incident response, and routine vulnerability scanning to address new threats proactively. Continuous monitoring ensures ongoing security and compliance, making applications more resilient over time.

Tooling and Techniques

• Proactive Monitoring: Secure SDLC employs continuous & runtime security monitoring with DAST, SIEM, and regular incident response.

• Tools: eBPF-based tools, proper security configurations in common monitoring tools and platforms like Grafana and Prometheus. Jit can be used to deploy DAST quickly to scan web apps in runtime.

The Evolution of a Secure SDLC

A secure SDLC transforms each phase—planning, coding, building, testing, deploying, and maintaining—by integrating tools and practices that identify and mitigate risks early.

his not only fosters a culture of shared responsibility but also ensures that applications are equipped to withstand the increasingly sophisticated security threats of today’s digital landscape.

As security becomes an intrinsic part of the SDLC, the principles of shift-left security and DevSecOps serve as guiding frameworks. They emphasize the need for cross-functional collaboration, the use of automated security tools, and the adoption of continuous monitoring to address vulnerabilities as they arise.  

By making security an integral part of the development lifecycle, innovation and resilience are no longer decoupled, proving that robust security and agile development can (and should) go hand in hand.