Apply the Secure Software Development Life Cycle (SDLC)
What is the Secure SDLC?
The Secure Software Development Life Cycle (SDLC) is the practice of integrating security testing, analysis, and controls into every phase of the software development process, rather than applying security as an afterthought or a final check before deployment. In the context of Cloud Application Security (CCSP), this involves adapting traditional development methodologies (Waterfall, Agile, DevOps) to account for cloud-specific risks, shared responsibility models, and automated CI/CD pipelines. The goal is to produce software that is secure by design, secure by default, and secure in deployment.
Why is it Important?
1. Cost Reduction: The cost to fix a security defect increases exponentially as the software moves through the SDLC. Fixing a bug during the Design phase is significantly cheaper than fixing it in Production.
2. Compliance and Governance: Many regulatory frameworks (GDPR, HIPAA, PCI-DSS) require specific security controls during development.
3. Application Assurance: In the cloud, where applications are often accessible via public APIs, reducing the attack surface is critical to prevent data breaches.
4. ISO/IEC 27034 Alignment: Following a Secure SDLC aligns with ISO/IEC 27034, the international standard for application security, which emphasizes integrating security into the organization's processes strategy.
How it Works: The Phases of Secure SDLC
To apply the Secure SDLC, specific security activities must be mapped to standard development phases:
Phase 1: Planning and Requirements
Security personnel must be involved to define security requirements alongside functional requirements. This includes risk assessments and determining compliance needs.
Phase 2: Design
This is often the most critical phase for CCSP exams. The primary activity here is Threat Modeling (using methodologies like STRIDE or DREAD) to identify potential attack vectors. Secure architecture decisions, such as encryption standards and identity management integration, are made here.
Phase 3: Development (Coding)
Developers write code following Secure Coding Standards (e.g., OWASP guidelines). Activities include Static Application Security Testing (SAST), which analyzes source code for vulnerabilities without executing it, and peer code reviews.
Phase 4: Testing
This phase involves verifying that the security controls work. Key activities include Dynamic Application Security Testing (DAST), which interacts with the running application to find runtime vulnerabilities, vulnerability scanning, and fuzz testing.
Phase 5: Deployment
In the cloud, this involves secure configuration management and Immutable Infrastructure. Security teams verify that the production environment is hardened and that secrets (API keys) are managed securely.
Phase 6: Operations and Maintenance
Continuous monitoring, logging, incident response, and patching. In a DevSecOps environment, this feeds back into the planning phase immediately.
Exam Tips: Answering Questions on Apply the Secure Software Development Life Cycle (SDLC)
1. The "Shift Left" Concept
If a question asks how to reduce the cost of security or improve code quality efficiently, look for answers that involve moving security steps earlier in the process (shifting left), such as performing SAST during coding rather than DAST during testing.
2. Mapping Activities to Phases
You will likely see questions asking where a specific tool or action fits.
- Threat Modeling belongs to the Design phase.
- SAST (White-box testing) belongs to the Development/Build phase.
- DAST (Black-box testing) belongs to the Testing/QA phase.
3. ISO/IEC 27034
Memorize that ISO/IEC 27034 is the standard specifically for Application Security. It introduces the concept of an ONF (Organization Normative Framework) and ANF (Application Normative Framework).
4. Data Input Validation
Many questions regarding common vulnerabilities (like SQL Injection or XSS) are solved by implementing Input Validation. The best place to apply input validation is on the server-side, occurring during the Development phase.
5. Open Source vs. Proprietary
Be aware of the risks involved in using open-source libraries. The solution is Software Composition Analysis (SCA) to track dependencies and licensing issues.
6. Waterfall vs. Agile/DevOps
In Waterfall, security acts as a gate at specific milestones. In Agile/DevOps, security must be automated and integrated into the CI/CD pipeline (DevSecOps).