Secure Software Development: Building Security Into the Code from Day One

We can secure our access and secure our data; however, with software the engine driving innovation, it is also a prime target for cyber threats. With applications increasingly connected to sensitive data, APIs, and third-party ecosystems, attackers are exploiting vulnerabilities in code, dependencies, and misconfigurations.

To counter this, organizations must shift from bolting security on at the end to baking it into every phase of software development. This is the foundation of Secure Software Development, often aligned with DevSecOps practices, where security becomes a shared responsibility across development, operations, and security teams.

Why Secure Software Development Matters

• Over 80% of codebases contain open-source vulnerabilities.

• Application-layer attacks are now among the most common breach vectors.

• Regulatory frameworks (e.g., NIST SSDF, OWASP SAMM, ISO/IEC 27001) increasingly expect secure development practices.

• The cost to fix vulnerabilities increases exponentially the later they are found in the SDLC.

Secure software development is not just about fixing bugs—it's about preventing them from entering the system in the first place.

Static and Dynamic Application Security Testing (SAST/DAST)

An important way for many companies to protect themselves is through the use of SAST and DAST tooling. Scans that look through the code and various application packages deployed across the entirety of an organisation to highlight potential vulnerabilities or insecure coding practices.

Some of the core concepts of this tooling are outlined below:

Static Application Security Testing (SAST)

Scans source code, bytecode, or binaries before execution to identify vulnerabilities such as buffer overflows, SQL injection, or hardcoded credentials. Integrated directly into IDEs or CI/CD pipelines for early feedback.

Benefits:

• Finds issues early in the development lifecycle.

• No need to run the application.

• Supports compliance with secure coding standards (e.g., OWASP Top 10, CWE/SANS).

Examples: SonarQube, Fortify, Checkmarx, DeepSource, Veracode SAST

Dynamic Application Security Testing (DAST)

Simulates attacks on a running application (typically in a QA or staging environment) to find runtime vulnerabilities like cross-site scripting (XSS), insecure redirects, and exposed error messages.

Benefits:

• Provides a real-world attacker’s perspective.

• Finds configuration and runtime-related issues that SAST might miss.

• Complements penetration testing efforts.

Examples: OWASP ZAP, Burp Suite, Netsparker, PrismaCloud, Veracode DAST

Software Composition Analysis (SCA)

Modern software is heavily reliant on open-source components and third-party libraries. SCA tools scan application dependencies to identify:

• Known vulnerabilities (e.g., CVEs) in open-source packages

• License risks (e.g., GPL in commercial code)

• Outdated versions and missing patches

Why it matters:

• Attackers exploit known vulnerabilities in popular packages (e.g., Log4Shell).

• Dev teams often use transitive dependencies they’re unaware of.

• Open-source risk is often the biggest blind spot in software security.

Best practices:

• Integrate SCA into CI/CD pipelines.

• Maintain a Software Bill of Materials (SBOM).

• Apply automated alerts and fixes for vulnerable libraries.

Examples: Snyk, Black Duck, WhiteSource (Mend), GitHub Dependabot.

Secret Scanning and Dependency Vulnerability Scanning in CI/CD Pipelines

The following are critical types of scans that can be done through these SAST and DAST tools that help to narrow down specific security vulnerabilities:  

Secret Scanning

• Detects hardcoded secrets such as API keys, access tokens, and passwords in source code and repositories.

Why it matters:

• Exposed secrets are a direct path to compromise, especially in public repos.

• Attackers actively scan GitHub and GitLab for leaked credentials.

Best practices:

• Block commits containing secrets using Git hooks or pipeline gates.

• Rotate exposed credentials automatically.

• Use secret management tools (e.g., HashiCorp Vault, AWS Secrets Manager).

Tools: GitGuardian, TruffleHog, Gitleaks

Dependency Vulnerability Scanning

• Automatically scans package manifests (e.g., package.json, pom.xml, requirements.txt) for known vulnerabilities.

• Integrates into build and deploy pipelines, blocking releases if critical flaws are detected.

Why it matters:

• Shifts risk detection left, reducing release-time delays.

• Provides fast, automated remediation suggestions or pull requests.

Examples: Snyk, OWASP Dependency-Check, GitHub Advanced Security, Aqua Trivy

Beyond the Tools: Culture and Process

Secure software development, though, isn’t about tools though it requires several other important cultural and process steps to help drive the correct behaviours through an organisation:

• Security champions within development teams

• Threat modeling early in design phases

• Secure coding training and awareness

• Shift-left testing in Agile and DevOps workflows

When security becomes an enabler, not a blocker, teams build faster and more confidently.

Code Confidently, Ship Securely

With the incredible importance of software security across all modern applications, secure software development is essential, not optional. By embedding security testing, open-source management, and secret scanning into CI/CD pipelines, organizations can identify and remediate risks early, often, and automatically.

Building secure code from the start reduces rework, accelerates delivery, and protects users, turning security into a catalyst for innovation rather than a roadblock.