ISO/IEC 27001:2022 Annex A · Control 8.25

Secure Development Life Cycle: A Practical Implementation Guide

Embed security activities and evidence into every phase of software and system development.

This control concerns establishing and applying rules for secure development of software and systems.

Practical interpretation: Security should shape planning, design, build, testing, release and maintenance. A final penetration test cannot compensate for unsafe architecture and development practices.

What should the control achieve?

Development governance defines required security activities.
Risk determines assurance depth.
Security decisions and evidence follow the lifecycle.
Lessons and vulnerabilities improve the process.

Step-by-step implementation

Define lifecycle gates

Set activities and exit criteria for planning, design, build, test, release and maintenance.

Classify project risk

Use data, exposure, criticality, technology and compliance.

Assign responsibilities

Name product, engineering, security, testing and risk owners.

Integrate tooling

Use threat modeling, scanning, dependency checks, review and security tests.

Control release

Require resolved findings or authorized residual risk.

Measure improvement

Review defects, escapes and developer feedback.

What this could look like in practice

High-risk product changes require threat modeling, security requirements, peer review, automated scans and pre-release testing. Release blocks on critical unresolved findings unless the risk owner approves an exception.

Activity	Practical implementation	Evidence
Planning	Risk tier determines required security activities.	Project record
Design	Threat model identifies controls and abuse cases.	Threat model
Build	Pipeline scans code and dependencies.	Build report
Release	Security criteria and risk decisions are verified.	Release approval

Implementation evidence

Secure SDLC policy
Risk-tier model
Lifecycle gates
Threat models
Pipeline reports
Security tests
Release records
Improvement metrics

Useful metrics

Projects following required gates
Security defects escaping production
Critical findings at release
Time to remediate development findings

Common mistakes

Using one process for every risk level.
Engaging security only before release.
Running tools without owners for findings.
Treating agile as incompatible with documentation.
No feedback from production incidents.

Questions an auditor may ask

Which security activities apply by risk?
Show evidence across one project lifecycle.
Who accepts residual risk?
How do incidents improve development?

Implementation test: Select a recent feature and trace security requirements, design decisions, code assurance, tests and release approval.

Continue through Annex A

Explore the growing library of practical guides for all 93 Annex A controls.

Open the ISO 27001 Annex A Control Library

This independent educational guide paraphrases the practical intent of the control and does not replace the official ISO standards, professional advice or an organization-specific risk assessment. It is not affiliated with or endorsed by ISO.

ISO 27001 Annex A 8.25: Secure Development Life Cycle – Practical Implementation Guide