ISO 27001 Annex A 5.27 Learning from information security incidents
What it says
Knowledge gained from information security incidents shall be used to strengthen and improve the information security controls.
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What it means
In plain EnglishUse knowledge from past incidents to boost security and prevent future issues.
This control is about using past security incidents to make your organisation safer. It's like learning from mistakes so you don't repeat them, which reduces the chance of future problems and protects your data and systems.
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Why it matters
Neglecting to learn from past incidents can enable repeat attacks, causing prolonged disruptions, data loss and added financial costs.
How to implement
IT managers should set up a system to track all security incidents.
This means creating a process to record details about what happened, who was involved, and what was affected, which helps in understanding patterns or recurring issues.
HR teams should incorporate lessons from past incidents into employee training.
Update training materials with real-world examples to show staff how to spot and avoid security threats, strengthening overall organisational defence.
The board should ensure regular reviews of incident data to inform decision-making.
They can do this by holding quarterly meetings to discuss incident trends and necessary improvements in security policies based on these trends.
Compliance officers should use incident data to update risk assessments.
By analysing what went wrong and why, they can identify areas needing stronger controls as required by the ISO 27002:2022 guidance and Australian Privacy Act 1988.
IT staff should revise technical controls based on incident insights.
This involves tweaking settings, adding new security measures, or upgrading technology to prevent repeat incidents, ensuring alignment with recommendations from APRA and the ASD Essential Eight.
Keep it running
Run post-incident reviews, document lessons learned, assign remediation actions and deadlines, then update controls, playbooks and training accordingly.
Evidence and audit
- Check 1 of 5What an auditor asks for
Ask for
Request a copy of the incident tracking logs.
Look at
Examine the logs for completeness and detail, ensuring they cover all relevant incidents with a clear description of each event.
Good evidence
Logs should be detailed, up-to-date, and show all incidents with analysis of their causes and consequences.
- Check 2 of 5What an auditor asks for
Ask for
Request evidence of employee training updates related to incident learning.
Look at
Check training materials for inclusion of past incidents and preventative measures.
Good evidence
Training materials should include clear, recent examples from past incidents and instructions on how to avoid similar issues.
- Check 3 of 5What an auditor asks for
Ask for
Request minutes from board meetings where security incidents were discussed.
Look at
Look for discussions about incident trends and decisions for policy updates.
Good evidence
Minutes should reflect thoughtful analysis of incidents and outline specific policy or procedural changes.
- Check 4 of 5What an auditor asks for
Ask for
Request the latest risk assessment document.
Look at
Ensure the risk assessment incorporates findings from past incidents and identifies necessary control changes.
Good evidence
The risk assessment should clearly indicate areas where additional controls are needed, supported by incident data.
- Check 5 of 5What an auditor asks for
Ask for
Request a list of technical changes made in response to past incidents.
Look at
Review the details of changes and their alignment with the identified needs from incident analyses.
Good evidence
The list should show specific technical updates linked to preventing similar future incidents, reflecting insights from incident logs.
Mappings
Closest match in ASD Essentials for enterprise IT: IT.RES-04.1, Perform post-incident reviews to identify security gaps behind each incident stage, which this control covers in full and more.
ASD Information Security Manual: 2 mappings
This control supports ISM-0576.
Annex A 5.27 requires organisations to use knowledge from incidents to strengthen and improve information security controls. ISM-0576 requires a cyber security incident management policy and response plan, which creates the process framework where post-incident reviews and improvement actions can be embedded. ISM-0576 focuses on establishing incident management capability, while Annex A 5.27 focuses specifically on feeding incident learnings into control improvements.
This control depends on ISM-0125.
Annex A 5.27 requires that knowledge gained from information security incidents is used to strengthen and improve information security controls. ISM-0125 mandates maintaining a cyber security incident register, which provides the evidence base and trend data needed to derive lessons learned and prioritise control uplift. ISM-0125 is primarily about recording and tracking incidents, whereas Annex A 5.27 is about converting that knowledge into control changes.
ASD Essentials for enterprise IT: 2 mappings
- IT.RES-04.1Perform post-incident reviews to identify security gaps behind each incident stageBroader than
This control is broader than IT.RES-04.1.
IT.RES-04.1 requires post-incident reviews to identify the security gaps that enabled each stage of a cyber security incident. This is a specific way of gaining the knowledge from incidents that Annex A 5.27 requires to be used to strengthen and improve information security controls. Annex A 5.27 goes further by requiring that knowledge to be acted on, while IT.RES-04.1 focuses on identifying the gaps.
- IT.RES-04.2Evaluate monitoring coverage and response procedures after incidents and validate improvementsBroader than
This control is broader than IT.RES-04.2.
IT.RES-04.2 requires monitoring coverage and cyber security incident response procedures to be evaluated following cyber security incidents. This applies the learning from incidents required by Annex A 5.27, under which knowledge gained from incidents must be used to strengthen and improve information security controls, to two specific areas. Annex A 5.27 applies to all controls and requires improvements to be made, while IT.RES-04.2 is limited to evaluating monitoring and response.
Mappings show how controls relate across frameworks. They do not imply full equivalence or certification.
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ISO 27001 training
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