ISO/IEC 27005 Information Security Risk Management

ISO/IEC 27005 is the information security risk management standard within the ISO/IEC 27000 family, providing guidance on implementing the risk assessment and treatment requirements of ISO/IEC 27001 Clause 6. The 2022 edition (ISO/IEC 27005:2022) was substantially restructured to align with ISO 31000:2018 risk management principles and to better reflect the threat landscape of modern digital environments. ISO 27005 defines a risk management process comprising context establishment, risk assessment (identification, analysis, and evaluation), risk treatment, risk acceptance, risk communication and consultation, and risk monitoring and review. The standard is deliberately methodology-agnostic — it describes what a risk management process must accomplish without mandating a specific risk quantification approach, allowing organizations to apply qualitative, semi-quantitative, or quantitative methods depending on their maturity and data availability.

From an engineering perspective, ISO 27005 risk identification requires comprehensive asset inventories as a prerequisite — information assets, software assets, physical assets, services, and people — along with their associated vulnerabilities and applicable threat scenarios. The 2022 edition emphasizes event-based risk scenarios (a threat exploits a vulnerability to cause a consequence) rather than asset-centric enumeration, which aligns more naturally with threat modeling disciplines like STRIDE and PASTA. Risk analysis involves assessing likelihood and consequence to produce a risk level that can be evaluated against risk acceptance criteria defined by leadership. The risk treatment options — modify (implement controls), retain (accept), avoid (discontinue activity), or share (transfer via insurance or contracts) — each require documented decisions with assigned ownership and timelines. The treatment plan maps directly to ISO 27001 Annex A controls, creating a traceable link from identified risk to implemented control.

A practical nuance of ISO 27005 implementation is the tension between methodological rigor and operational practicality. Fully quantitative risk assessments using probabilistic loss exceedance models (as used in FAIR — Factor Analysis of Information Risk) provide more defensible numbers but require historical incident data and actuarial inputs that most organizations lack. Qualitative matrices (Low/Medium/High likelihood × Low/Medium/High impact) are simpler but produce results that vary with assessor judgment and are difficult to compare across assessments over time. The 2022 edition explicitly acknowledges this tension and recommends calibrated semi-quantitative approaches as a practical middle ground. Engineering organizations should also note that ISO 27005 risk assessments are living documents — the standard requires reassessment when significant changes occur (new systems, organizational changes, new threat intelligence), creating a continuous monitoring obligation rather than a point-in-time exercise.

We conduct ISO 27005:2022-aligned risk assessments using structured threat scenario workshops that produce asset inventories, threat-vulnerability pairings, and risk treatment plans mapped to ISO 27001 Annex A controls — all in a format ready for external certification audit review. Our risk register implementations are version-controlled artifacts with change history, owner assignments, and treatment status tracking integrated into your existing project management tooling. We use semi-quantitative risk scoring calibrated to your industry's threat profile, making results comparable across annual assessment cycles.

Compliance-Native Architecture Guide

Design principles and a structured checklist for building software that is compliant by default — not compliant by retrofit. Covers data architecture, access controls, audit trails, and vendor due diligence.