Implementing ISO 27001 Annex A 8.28 is the systematic application of secure coding principles to reduce software vulnerabilities and defend against malicious attacks. This control requires establishing mandated coding standards and automating security checks within the development pipeline. The primary business benefit is ensuring software integrity and preventing costly security breaches.
ISO 27001 Annex A Secure Coding Implementation Checklist
Use this implementation checklist to achieve compliance with ISO 27001 Annex A 8.28. This control mandates the application of secure coding principles to software development to reduce vulnerabilities and defend against attacks.
1. Establish Mandated Coding Standards
Control Requirement: A defined set of secure coding principles must be applied to all development projects.
Required Implementation Step: Formally adopt the OWASP Top 10 or CWE/SANS Top 25 as your baseline standard. Configure your IDE linters (e.g., ESLint, SonarLint) to enforce these rules locally on developer machines before code is even committed.
Minimum Requirement: Developers cannot push code that violates the defined linter configuration file.
2. Implement Pre-Commit Security Hooks
Control Requirement: Secure coding rules must be enforced technically, not just procedurally.
Required Implementation Step: Install pre-commit hooks (using tools like Husky or pre-commit) that scan for hardcoded secrets, API keys, and basic syntax vulnerabilities. This creates a hard gate that prevents insecure code from entering the version control system.
Minimum Requirement: A commit containing “API_KEY=” is rejected by the local git client.
3. Enforce Input Validation Libraries
Control Requirement: All external input must be validated to prevent injection attacks.
Required Implementation Step: Standardise on a strict input validation library for your framework (e.g., Joi for Node.js, Hibernate Validator for Java). Ban the use of raw input processing and require positive validation (allow-listing) for all form data and API parameters.
Minimum Requirement: No API endpoint accepts raw input without passing through a validation schema.
4. Automate Dependency Scanning (SCA)
Control Requirement: Third-party libraries must be secure and free from known vulnerabilities.
Required Implementation Step: Integrate Software Composition Analysis (SCA) tools (like OWASP Dependency-Check or Snyk) into your CI/CD pipeline. Configure the build to fail automatically if any library with a CVSS score of 7.0 or higher is detected.
Minimum Requirement: You cannot deploy a build containing a “Critical” severity vulnerability in a dependency.
5. Sanitize Output Data
Control Requirement: Output must be encoded to prevent Cross-Site Scripting (XSS).
Required Implementation Step: Configure your templating engine (e.g., React, Thymeleaf) to auto-escape all variables by default. Manually audit any instance where developers use “dangerouslySetInnerHTML” or equivalent bypass methods to ensure strict sanitisation is applied.
Minimum Requirement: Context-aware encoding is applied to all user-generated content displayed in the browser.
6. Secure Error Handling
Control Requirement: Error messages must not reveal sensitive system information.
Required Implementation Step: Configure global error handlers to strip stack traces, database schema details, and server versions from HTTP responses returned to the client. Log the full details internally to a secure SIEM, but show the user a generic “An error occurred” message.
Minimum Requirement: API responses never return a 500 error containing a stack trace.
7. Mandate Peer Code Reviews
Control Requirement: Code changes must be reviewed by a qualified peer prior to merging.
Required Implementation Step: Configure your repository (GitHub/GitLab) branch protection rules to require at least one approval from a designated code owner. The reviewer must specifically check for security logic flaws that automated tools miss.
Minimum Requirement: No code is merged to the ‘Main’ branch without a documented peer approval.
8. Encrypt Data at the Application Level
Control Requirement: Sensitive data must be protected by the application logic.
Required Implementation Step: Identify sensitive fields (PII, financial data) and implement application-level encryption before writing to the database. Ensure keys are managed via a Key Management Service (KMS) and never stored in the application config files.
Minimum Requirement: Database administrators cannot read clear-text credit card numbers or passwords.
9. Disable Insecure Framework Features
Control Requirement: The development framework itself must be configured securely.
Required Implementation Step: Review the default settings of your framework (Django, Rails, Express). Explicitly disable debug mode in production, remove default welcome pages, and set secure HTTP headers (HSTS, CSP, X-Frame-Options) in the application middleware.
Minimum Requirement: Production headers score an ‘A’ on securityheaders.com.
10. Verify Through Static Analysis (SAST)
Control Requirement: Code must be scanned for security flaws before deployment.
Required Implementation Step: Embed a Static Application Security Testing (SAST) tool into the build pipeline. Ensure it scans the entire codebase on every pull request and blocks the merge if high-severity security hotspots are found.
Minimum Requirement: A clean SAST report is a prerequisite for every release candidate.
ISO 27001 Annex A 8.28 SaaS / GRC Platform Implementation Failure Checklist
| Control Requirement | The ‘Checkbox Compliance’ Trap | The Reality Check |
|---|---|---|
| Secure Coding Standards | SaaS tool provides a generic “Secure Coding Policy” PDF to sign. | Developers sign the PDF but continue to copy-paste vulnerable code from Stack Overflow because no linter stops them. |
| Input Validation | SaaS tool asks “Is input validated?” (Yes/No). | The team relies on client-side JavaScript validation which is easily bypassed by Curl or Postman. |
| Dependency Management | SaaS tool checks if you have a “Vendor Management” policy. | Your `package.json` includes a library from 2018 with a known RCE vulnerability because the GRC tool doesn’t scan code. |
| Error Handling | SaaS tool verifies you have an “Incident Response Plan”. | Your production API is leaking full database stack traces to the public internet, helping attackers map your schema. |
| Code Review | SaaS tool confirms “Change Management” process exists. | The “Reviewer” is the same person as the “Coder”, or they just click “Approve” without reading the security logic. |
| Secret Management | SaaS tool checks for an “Access Control Policy”. | AWS Access Keys are hardcoded in `config.js` and committed to a public repo because no pre-commit hook exists. |
| Framework Security | SaaS tool asks “Are systems hardened?”. | The application is running in “Debug Mode” in production, exposing environment variables and configuration details. |
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