With over 92% of companies experiencing an application-related breach last year (Source), a secure software development lifecycle (SDLC) is absolutely critical for protecting your applications from security threats and vulnerabilities throughout the development lifecycle. With application-related breaches on the rise, integrating security into your development process is more important than ever.
A secure SLDC integrates security practices throughout the software development process. Secure SDLC frameworks help meet regulatory requirements and avoid penalties.
Integrating security measures into the development process and adopting ‘shift left security’ can significantly help ensure the delivery of secure software within your enterprise, and pentesting plays a significant role in this.
This guide is for software development leaders, security professionals, and developers seeking to implement secure software development cycles.
1. Securing the Design Phase
Secure design patterns and principles should be enforced from day one- this means as early as the design phase. Threat modelling and risk management both help identify and mitigate security threats, enabling you to build a secure architecture for software development.
This is when secure coding practices and security controls should be considered and enforced: inform your development team of what secure coding looks like, implement security controls that prevent common vulnerabilities, and ensure that all application code adheres to established secure coding standards to minimise security risks throughout the development process.
2. Getting Your Development Team on Board With SDLCs
Your development lifecycle is only as secure as your development teams know how to make it; therefore, it’s important to have security specialists involved with the development process to consider security considerations are properly addressed.
Methods for enforcing SDLC amongst your development team as a security leader include:
- Embed security from day one: Include security requirements in planning, not as an afterthought.
- Appoint security champions: Designate security-conscious developers in each team to spot issues early. This is a collaborative exercise that is good general practice, as it promotes clean, maintainable code and encourages knowledge sharing.
- Build in threat modelling: Map potential attack vectors during the design phase before code gets written.
- Set mandatory security gates: Establish checkpoints at each SDLC stage that must be passed before progressing.
- Automate security testing: Integrate SAST, DAST, and vulnerability scanning into your CI/CD pipeline.
- Enforce secure code reviews: Make security-focused peer reviews mandatory using clear checklists.
- Train regularly: Provide practical, ongoing training on secure coding practices and common vulnerabilities.
- Track security metrics: Monitor vulnerabilities found, remediation times, and test coverage to drive improvement.
- Create feedback loops: Feed pentest findings and incidents back into the SDLC to prevent repeat issues.
Next, it’s important to ensure the coding practices you are enforcing are also secure and well understood by your development team.
3. Enforcing Secure Coding
Secure coding standards and best practices should be followed to prevent security vulnerabilities. To tackle this, focus on these three essential tactics:
- Apply secure coding practices, such as input validation and secure data storage,consistently.
- Perform regular code reviews and automated testing regularly to flag security issues before they can spiral into heftier problems later in the development cycle.
- Apply secure configurations and security patches to prevent known vulnerabilities and common vulnerabilities.
- Automated static code analysis tools help detect flaws early in the implementation phase.
- Security testing, including both dynamic and static application security testing and static application security testing, should be performed regularly.
- Use penetration testing to identify and remediate more complex or business logic-specific issues.
4. Reviewing the Development Environment
- The development environment should be secure, with access controls and version control in place.
- Secure coding practices and security requirements should be enforced in the development environment.
- Development teams should use secure tools and technologies to prevent security vulnerabilities.
- The development environment should be regularly monitored for security issues.
5. Integrating Pentesting into the Software Development Cycle
Security within your SDLC shouldn’t be isolated to a single part of the process. In fact, security should be integrated into every phase, ensuring that vulnerabilities are identified and your risk surface is well managed from the get-go.
Using the steps above, requirements should be defined and integrated into the development system. Integrating pentesting into your SDLC pipeline is a great step in shifting your security ‘left’, introducing a proactive mindset to vulnerability identification and attack surface management.
How Security Leaders Can Integrate Pentesting into the SDLC:
- Start with threat modelling: Before development begins, work with teams to identify high-risk areas that warrant targeted pentesting during later phases.
- Schedule regular testing intervals: Plan pentests at key milestones: post-design (architecture review), mid-development (feature testing), pre-production, and post-release.
- Automate where possible: Integrate automated security scanning tools into your pipeline for continuous testing. Use manual pentesting for complex scenarios and logic flaws that automation misses.
- Create a penetration testing roadmap: Map which applications, APIs, and infrastructure components need testing, how often, and at what level of testing (black box, grey box, white box).
- Build remediation into sprint planning: When pentests identify vulnerabilities, make sure there’s capacity in development sprints to fix them. Security debt shouldn’t pile up.
- Establish clear escalation paths: Define severity ratings and response timeframes so critical vulnerabilities get patched immediately, whilst lower-risk issues are planned appropriately.
- Use pentesting to validate fixes: After remediation, retest to confirm vulnerabilities are properly resolved, not just patched over.
For a more actionable tutorial on introducing pentesting into your SDLC and CI/CD pipeline, check out our expert-led blog, “Penetration Testing into your CI/CD Pipeline: A DevSecOps Guide”.
A secure software development lifecycle (SSDLC) integrates security practices throughout every stage of the software development process.
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