ISO 27001 Annex A 5.27 Learning From Information Security Incidents

Introduction

I am going to show you what ISO 27001:2022 Annex A 5.27 Learning from Information Security Incidents is, what’s new, give you ISO 27001 templates, an ISO 27001 toolkit, show you examples, do a walkthrough and show you how to implement it.

I am Stuart Barker the ISO 27001 Ninja and using over two decades of experience on hundreds of ISO 27001 audits and ISO 27001 certifications I show you exactly what changed in the ISO 27001:2022 update and exactly what you need to do for ISO 27001 certification.

What is ISO 27001 Learning from Information Security Incidents?

ISO 27001:2022 Annex A 5.27 Learning from information security incidents is an ISO 27001 control that requires an organisation to learn from information security events to improve.

ISO 27001 Annex A 5.27 Purpose

Annex A 5.27 is a preventive control that ensures the reduction in the likelihood or consequences of future incidents.

ISO 27001 Annex A 5.27 Definition

ISO 27001:2022 defines Annex A 5.27 as:

Knowledge gained from information security incidents should be used to strengthen and improve the information security controls.

ISO 27001:2022 Annex A 5.27 Learning from information security incidents

Implementation Guide

An information security incident is an event that could potentially have a negative impact on the confidentiality, integrity, or availability of information. The consequences of an incident can vary depending on the nature of the incident, the systems and data affected, and the organisations response.

As part of your incident management you are going to implement a step that looks at learning from incidents. You will consider this documented process and how you will analyse incidents, identify the root cause and then make decisions on corrective actions as required.

Root Cause Analysis

What is root cause analysis?

It is technique that looks to see what the actual cause of an incident was. It is not about identifying the symptoms but what actually caused them and the incident to occur. Consider, I have put on weight. Root cause does not look at the fact your clothes do not fit any more but on why. Through analysis you would likely discover the root cause is you eat too much and don’t exercise enough.

How to perform root cause analysis

A good way to is to use the technique of the Five Why’s. By asking the question why five times in a row you can get to the root of the problem.

I have put on weight.

Why? Because I am bigger than before

Why? Because I eat too much

Why? Because I am unhappy

Why? Because I work too hard

Why? Because I need money.

Root cause of all evil = money.

It can actually be a very effective technique.

What to do with the result

Once we know what the root cause of an information security incident is we can now start to make decision as to what to do. It may be that

• This requires no further action
• This requires corrective action
• This requires continual improvement
• This is a risk and needs to be managed via risk management

Implementation Conclusion

This guide provides a framework for identifying the root cause, lessons learnt and improvements of an information security incident. The guide should be used in conjunction with your information security incident management plan.

The standard that relates to information security management for further reading if required is ISO/IEC 27035

ISO 27001 Templates

You can save months of effort with these templates that take 25 years of experience and distill it in a pack of prewritten best practice awesomeness. We have included guides on how to respond to incidents and resources to help your implementation.

How to comply

To comply with ISO 27001:2022 Annex A 5.27 you are going to implement the ‘how’ to the ‘what’ the control is expecting. In short measure you are going to:

1. Manage information security incidents to resolution
2. Perform root cause analysis to identify what caused it
3. Make a decision on what to do next
4. Record information security lessons learnt.

How to pass an audit

To pass an audit of ISO 27001:2022 Annex A 5.27 Learning from information security incidents you are going to make sure that you have followed the steps above in how to comply.

1. Have a documented process for root cause analysis and lessons learnt.
2. Implement the lessons learnt process
3. Monitor the effectiveness of the lessons learnt process
4. Review and update the lessons learnt process as needed.

You are going to check that it is working by first conducting an internal audit, following the How to Conduct an ISO 27001 Internal Audit Guide.

What will an audit check?

The audit is going to check a number of areas. Lets go through the main ones

1. That you have documented your root cause and lessons learnt process

The audit will check the documentation, that you have reviewed it and signed and it off and that it represents what you actually do not what you think they want to hear.

2. That you can demonstrate the process working

They are going to ask you for evidence to the lessons learnt process and take one example. For this example you are going to show them and walk them through the process and prove that you followed it and that the process worked.

3. That you can learn your lesson

Documenting your lessons learnt and following this through to continual improvements or incident and corrective actions will be checked. They want to see that not only did you respond but that you learnt from it and did something to improve that reduced or eliminated the possibility of it happening again.

Top 3 Mistakes People Make

The top 3 Mistakes People Make For ISO 27001:2022Annex A 5.27 are

1. Not having a documented information security incident management plan.

This is the most common mistake made by organisations. A documented information security incident management plan is essential for effective incident response. It should include the following:

• A process for root cause analysis and lessons learnt

2. Not implementing the information security incident management plan.

Even if you have a documented information security incident management plan, it is not enough to simply have the plan. The plan must be implemented in order to be effective. This means assigning responsibility for implementing the plan, providing training on the plan, and testing the plan.

3. Not monitoring the effectiveness of the information security incident management lessons learnt.

Once the information security incident management lessons learnt is implemented, it is important to monitor its effectiveness. This means reviewing reports of information lessons learnt, root cause analysis, risk registers, corrective action logs and actual corrective actions implemented as needed.

By avoiding these mistakes, you can ensure that you have an effective information security incident management plan in place.

Why is ISO 27001 Learning from Information Security Incidents Important?

As the saying goes, shit happens. It is facts of life. No system or security is 100% We cannot be on the back foot when the inevitable happens and effective incident management can eliminate or reduce the impact of information security incidents.

ISO 27001:2022 Annex A 5.27 is important because it provides guidance on how we learn and continually improve as a result of incidents. Information security incidents can have a significant impact on an organisation, so it is important to have a plan in place for how to reduce them in future. The guidance in ISO 27001:2022 Annex A 5.27 can help you to develop and implement an effective information security incident lessons learnt plan.

The following are some of the benefits of having an effective information security incident lessons learnt process:

• It can help to reduce the impact of information security incidents.
• It can help to protect the organisations reputation.
• It can help to comply with legal and regulatory requirements.
• It can help to improve the organisations overall information security posture.

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Matrix of ISO 27001 controls and ISO 27001 attribute values

Control type	Information security properties	Cybersecurity concepts	Operational capabilities	Security domains
Preventive	Confidentiality	Identify	Information Security Event Management	Defence
	Integrity	Protect
	Availability