ISO 27001 Annex A 5.23 Information Security For Use Of Cloud Services

ISO 27001 Information Security For Use Of Cloud Services

In this ultimate guide to ISO 27001 Annex A 5.23 Information Security For Use Of Cloud Services you will learn

• What is ISO 27001 Annex A 5.23
• How to implement ISO 27001 Annex A 5.23

I am Stuart Barker, the ISO 27001 Ninja and author of the Ultimate ISO 27001 Toolkit.

With over 30 years industry experience I will show you what’s new, give you ISO 27001 templates, show you examples, do a walkthrough and show you how to implement it for ISO 27001 certification.

What Is ISO 27001 Annex A 5.23 Information Security For Use Of Cloud Services?

ISO 27001 Annex A 5.23 Information security for use of cloud services is an ISO 27001 control that requires an organisation to specify and manage information security for the use of cloud services.

ISO 27001 Annex A 5.23 Purpose

The purpose of ISO 27001 Annex A 5.23 is a preventive control that ensures you specify and manage information security for the use of cloud services.

ISO 27001 Annex A 5.23 Definition

The ISO 27001 standard defines ISO 27001 Annex A 5.23 as:

Processes for acquisition, use, management and exit from cloud services should be established in accordance with the organisation’s information security requirements.

ISO27001:2022 Annex A 5.23 Information security for use of cloud services

ISO 27001 Annex A 5.23 Implementation Guide

Cloud services can be treated to all intents and purposes like any supplier. The standard calls them out, because, in some ways it feels like they felt they had to. It gives a list of requirements that are unrealistic and then acknowledges it is unlikely you can meet them.

Before we look at what you can do let us paraphrase what the standard thinks as the get out.

It absolutely acknowledges that yes, cloud service agreements are pre defined and not open to negotiation on the whole. So why give a list of requirements? Who knows. This is about basic good practice of supplier management. They could have said that. But they did not.

You will ensure

ISO 27001 Annex A 5.21 Managing Information Security In The ICT Supply Chain

ISO 27001 Annex A 5.22 Monitor, Review And Change Management Of Supplier Services

Follow good third party supplier management as previously covered including risk management and if at any point you are worried seek additional guidance from the standard which will guide you and then say, but we appreciate this cannot be done.

Cloud Service Agreements

I am not even going to cover what the standard thinks should be in cloud service agreements as already stated, the standard acknowledges that these are non negotiable. If you are interested, refer to your copy of the ISO 27002 standard.

How to write a Cloud Security Policy

A step-by-step tutorial on how to create a cloud security policy for ISO 27001 in under 10 minutes. I walk you through the process of creating a policy, including what to include in the policy and how to comply with the ISO 27001 standard.

For a deeper understanding of the ISO 27001 Cloud Security Policy see the ultimate guide: Cloud Security Policy: Ultimate Guide (+ template)

ISO 27001 Templates

The standard requires a topic specific ISO 27001 Cloud Security Policy and you will need the ISO 27001 Third Party Supplier Register to record and manage your cloud suppliers.

How to comply

To comply with ISO 27001 Annex A 5.23 you are going to implement the ‘how’ to the ‘what’ the control is expecting. In short measure you are going to include Cloud Services in supplier management and:

• Implement a topic specific policy
• Implement a supplier management process
• Include in your supplier management process supplier acquisition and supplier transfer
• Implement a third party supplier register
• Have agreements with all suppliers that cover information security requirements
• Have information security assurances for critical suppliers as a minimum and ideally all relevant suppliers
• Monitor those suppliers
• Respond to adverse incidents in a structured way

How to pass an audit

To pass an audit of ISO 27001 Annex A 5.23 Information security for use of cloud services you are going to make sure that you have supplier management that also covers cloud services and that you have followed the steps above in how to comply.

You are going to do that 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 most common

1. That you have a cloud supplier agreements in place

The auditor is going to check that you have agreements in place with cloud suppliers that cover the information security requirements. It will check that those agreements are in date and cover the products and / or services acquired.

2. That you have an ISO 27001 Supplier Register

You will need an ISO 27001 Supplier Register to record and manage your suppliers. Make sure it is up to date and reflects your reality.

3. Documentation

They are going to look at audit trails and all your documentation and see that is classified and labelled. All the documents that you show them, as a minimum if they are confidential should be labelled as such. Is the document up to date. Has it been reviewed in the last 12 months. Does the version control match.

Top 3 Mistakes People Make

The top 3 Mistakes People Make For ISO 27001 Annex A 5.23 are

1. You have do not monitor cloud suppliers

Make sure that there are reviews and monitors in place. Perhaps meetings. Perhaps reports. Perhaps dashboards. Be sure to be able to evidence that you review and monitor those suppliers. You will have processes for adverse advents so do not be surprised if you are asked to evidence an adverse event, problem or issue and that you followed your process.

2. You have no assurance they are doing the right thing for information security

Make sure you have done your security assessment and can place your hands on an in date certificate such as an ISO 27001 Certification for assurance they are doing the right thing. It needs to be in date a cover the products and / or services you have acquired and are using form the supplier.

3. Your document and version control is wrong

Keeping your document version control up to date, making sure that version numbers match where used, having a review evidenced in the last 12 months, having documents that have no comments in are all good practices.

ISO 27001 Annex A 5.23 FAQ

ISO 27001 Controls and Attribute Values

Control type	Information security properties	Operational capabilities	Security domains
Preventive	Confidentiality	Supplier relationships security	Protection
	Integrity		Governance and ecosystem
	Availability