A.5.25·medium·Component: Organizational controlsWhat this control requires
The organization shall assess information security events and decide if they are to be categorized as information security incidents.
In plain English
The organization shall assess information security events and decide if they are to be categorized as information security incidents. In practice, this means you can prove you information information security-level controls on a defined cadence.
Why it matters
ISO 27001 certification depends on showing each Annex A control is either implemented or explicitly justified for exclusion in the Statement of Applicability (SoA). Certification bodies sample controls during surveillance audits, and a missing SoA entry — or implementation that doesn't match the SoA wording — is a finding.
What an auditor looks for
An ISO 27001 lead auditor looks for: (1) an SoA entry covering the control with justification, (2) a documented procedure or policy implementing it, (3) records that prove the procedure runs (logs, tickets, training records) and (4) management-review evidence that effectiveness is monitored.
Within Organizational controls, the assessor will trace your implementation back to the catalogue reference (Annex A A.5.25) and look for objective evidence on the latest two assessment cycles.
How to implement
Incident Response
Runbook. Maintain a runbook keyed by incident type with named roles (IC, comms, scribe), an out-of-band comms channel, and a 72-hour timeline for external notification.
Tabletop. Run a quarterly tabletop exercise (ransomware, insider, supply-chain) and feed gaps back into the runbook.
Vulnerability Management
Scanners. Pair an unauthenticated scanner (Nessus / Qualys / Tenable.io) for external surface with an authenticated agent for OS/library CVEs on every host.
SLA. Document remediation SLAs by CVSS / EPSS: critical 7 days, high 30 days, medium 90 days; report monthly trend to leadership.
Containers. Scan images in CI (Trivy / Grype / Snyk Container) AND at runtime; block deploys on critical findings without exception.
Operational checklist
- Information. Document the trigger, the owner and the cadence.
- Management. Document the trigger, the owner and the cadence.
- Assessment. Document the trigger, the owner and the cadence.
- Response. Document the trigger, the owner and the cadence.
- Security. Document the trigger, the owner and the cadence.
- Scope: information security, management, information security incidents.
Evidence to collect
- Ticketing Workflow.
ticketing_workflowevidence
Workflow metrics (ServiceNow, Jira) show approvals and remediation. Focus: Assessment and decision on information security events.
Common pitfalls
- Runbooks that name a role but no person, or list a paging channel that no longer exists.
- Scans that hit only the perimeter; missing authenticated scans of OS, runtime libs and base images so most CVEs are invisible.
How it maps to other frameworks
Computed from shared tags, control component and key-operation subjects — handy when you are reconciling controls across an audit.
- NIST SP 800-53 Rev. 5 IR-9(2) — Training
- BSI C5:2020 SIM-03 — Documentation and reporting of security incidents
- NIST SP 800-171 Rev. 3 3.6.2 — Incident Monitoring, Reporting, and Response Assistance
- SOC 2 (2017 TSC) CC7.4 — Incident Response
- ISO/IEC 42001:2023 A.8.4 — Communication of incidents
Related controls in ISO/IEC 27001:2022
- Annex A A.5.27 — Learning from information security incidents
- Annex A A.5.8 — Information security in project management
- Annex A A.5.24 — Information security incident management planning and preparation
- Annex A A.5.26 — Response to information security incidents
- Annex A A.5.1 — Policies for information security
- Annex A A.5.4 — Management responsibilities
References
- ISO/IEC JTC 1/SC 27 — ISO/IEC 27001:2022
- Catalogue identifier:
Annex A A.5.25
Topics: incident responsechange managementvulnerability management