ISO 27001 Annex A 8.12 Data Leakage Prevention

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ISO 27001 Data Leakage Prevention

I am going to show you what ISO 27001:2022 Annex A 8.12 Data Leakage Prevention is, what’s new, give you ISO 27001 templates, 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 it?

ISO 27001:2022 Annex A 8.12 Data Leakage Prevention is an ISO 27001 control that requires an organisation to stop data from being extracted or leaked from systems. This is usually done as a result of known weakness or having services and functionality enabled that is not needed and is easy to manipulate.


ISO 27001:2002 Annex A 8.12 is preventive control and a detective control that is to detect and prevent the unauthorised disclosure and extraction of information by individuals or systems. 


The ISO 27001 standard defines ISO 27001:2022 Annex A 8.12 as:
Data leakage prevention measures should be applied to systems, networks and any other devices that process, store or transmit sensitive information. 

– ISO 27001:2022 Annex A 8.12 Data Leakage Prevention.

Implementation Guide

You are going to have to ensure that you:

  • Identify the information that you want to protect
  • Classify the information that you want to protect
  • Implement controls to protect the information based on risk, classification and business need
  • keep records
  • Test the controls that you have to make sure they are working

There are several approaches to data leakage prevention and the most common is to implement a data leakage prevention tool.

Data Leakage Prevention Tool

A Data Leakage Prevention Tool (DLP) is a specific tool that has been designed to track, detect and protect information based on rules using technology.

These tools can often be applied to structured and unstructured data. They can detect and / or prevent the disclosure of sensitive data for example sending information to, or from, personal and cloud emails, and sending information to cloud storage devices.

The more traditional examples of data leakage prevention are the locking down, or preventing the use of, attached media such as external hard drives and USB devices. Also the restricting of printing.

Implementing a DLP tool will take some planning. It can be easy to implement a tool that prevents people from being able to carry out their role. Spending time to understand what people need to do and then implementing proportionate controls is the key.

A good approach to implementing a DLP tool would be to first implement it in monitoring mode and to analyse the results before turning on more restrictive controls. The ability to request access or appeal a blocked control will help maintain the smooth operation of the business.

It is also important to consult with your legal team and ensure that what ever you do it is within the bounds of all laws and regulations. To do their job correctly, DLP tools will have access to all data and often the personal data of employees and customers.

Some things cannot be covered directly in a DLP tool. Taking screen shots, the use of cameras, video streaming of screens should be addressed in terms and conditions of employment, policies, training, education and physical controls such as not allowing cameras or phones into the work environment.

Backups can be a source of data leakage so having a strong backup policy that requires backups to be encrypted should be considered.


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How to comply

To comply with ISO 27001:2022 Annex A 8.12 you are going to implement the ‘how’ to the ‘what’ the control is expecting.
In short measure you are going to:

  • Understand and record the legal, regulatory and contractual requirements you have for data
  • Conduct a risk assessment
  • Based on the legal, regulatory, contractual requirements and the risk assessment you will implement an
    information classification scheme
  • Implement and communicate your topic specific policy on access control
  • Document and implement your processes and technical implementations for data leakage prevention
  • Check that the controls are working by conducting internal audits

How to pass an audit

To pass an audit of ISO 27001:2022 Annex A 8.12 Data leakage prevention you are going to make sure 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 auditor check?

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

That you have documentation

What this means is that you need to show that you have documented your legal, regulatory and contractual requirements
for data leakage prevention. Where data protection laws exist that you have documented what those laws are and what those
requirements are. That you have an information classification scheme and a topic specific policy for access control and
that you have documented your data leakage prevention techniques.

That you have have implemented data leakage prevention appropriately

They will look at systems to seek evidence of data leakage prevention. They will review endpoints to see that it is installed. System generated reports and logs will be reviewed. Process documents will be read and processes observed to ensure the documents are being followed. Examples of where the DLP has caught and handled something will be sought.

That you have conducted internal audits

The audit will want to see that you have tested the controls and evidenced that they are operating. This is usually in the form of the required internal audits. They will check the records and outputs of those internal audits.

Top 3 Mistakes People Make

In my experience, the top 3 mistakes people make for ISO 27001:2022 Annex A 8.12 Data leakage prevention are

You block everything

This is a common mistake we see. That the teams in charge of the data leakage prevention tool become a bit over zealous and lock everything down causing annoyance, irritation and preventing the business from operating. Be sure to implement proportionately.

This is a massive mistake that we see, where people assume ISO 27001 is just information security and forget that it also checks that appropriate laws are being followed, and in particular data protection laws. Cost saving by not having a data protection expert or ignoring data protection law entirely is a common mistake we see people make when cutting corners and saving costs.

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.

Why is data leakage prevention important?

Data leakage is a common way for people to gain access to information that they should not. Rather than rely on hacking or technical exploits it usually relies on the mis use of genuine product features. By applying policy, procedure and control based on an understanding of risk and business requirement can reduce the likelihood of information falling into the wrong hands.

ISO 27001:2022 requirements

Organisational Controls - A5

ISO 27001 Annex A 5.1 Policies for information security

ISO 27001 Annex A 5.2 Information Security Roles and Responsibilities

ISO 27001 Annex A 5.3 Segregation of duties

ISO 27001 Annex A 5.4 Management responsibilities

ISO 27001 Annex A 5.5 Contact with authorities

ISO 27001 Annex A 5.6 Contact with special interest groups

ISO 27001 Annex A 5.7 Threat intelligence – new

ISO 27001 Annex A 5.8 Information security in project management

ISO 27001 Annex A 5.9 Inventory of information and other associated assets – change

ISO 27001 Annex A 5.10 Acceptable use of information and other associated assets – change

ISO 27001 Annex A 5.11 Return of assets

ISO 27001 Annex A 5.11 Return of assets

ISO 27001 Annex A 5.13 Labelling of information

ISO 27001 Annex A 5.14 Information transfer

ISO 27001 Annex A 5.15 Access control

ISO 27001 Annex A 5.16 Identity management

ISO 27001 Annex A 5.17 Authentication information – new

ISO 27001 Annex A 5.18 Access rights – change

ISO 27001 Annex A 5.19 Information security in supplier relationships

ISO 27001 Annex A 5.20 Addressing information security within supplier agreements

ISO 27001 Annex A 5.21 Managing information security in the ICT supply chain – new

ISO 27001 Annex A 5.22 Monitoring, review and change management of supplier services – change

ISO 27001 Annex A 5.23 Information security for use of cloud services – new

ISO 27001 Annex A 5.24 Information security incident management planning and preparation – change

ISO 27001 Annex A 5.25 Assessment and decision on information security events 

ISO 27001 Annex A 5.26 Response to information security incidents

ISO 27001 Annex A 5.27 Learning from information security incidents

ISO 27001 Annex A 5.28 Collection of evidence

ISO 27001 Annex A 5.29 Information security during disruption – change

ISO 27001 Annex A 5.31 Identification of legal, statutory, regulatory and contractual requirements

ISO 27001 Annex A 5.32 Intellectual property rights

ISO 27001 Annex A 5.33 Protection of records

ISO 27001 Annex A 5.34 Privacy and protection of PII

ISO 27001 Annex A 5.35 Independent review of information security

ISO 27001 Annex A 5.36 Compliance with policies and standards for information security

ISO 27001 Annex A 5.37 Documented operating procedures 

Technology Controls - A8

ISO 27001 Annex A 8.1 User Endpoint Devices

ISO 27001 Annex A 8.2 Privileged Access Rights

ISO 27001 Annex A 8.3 Information Access Restriction

ISO 27001 Annex A 8.4 Access To Source Code

ISO 27001 Annex A 8.5 Secure Authentication

ISO 27001 Annex A 8.6 Capacity Management

ISO 27001 Annex A 8.7 Protection Against Malware

ISO 27001 Annex A 8.8 Management of Technical Vulnerabilities

ISO 27001 Annex A 8.9 Configuration Management 

ISO 27001 Annex A 8.10 Information Deletion

ISO 27001 Annex A 8.11 Data Masking

ISO 27001 Annex A 8.12 Data Leakage Prevention

ISO 27001 Annex A 8.13 Information Backup

ISO 27001 Annex A 8.14 Redundancy of Information Processing Facilities

ISO 27001 Annex A 8.15 Logging

ISO 27001 Annex A 8.16 Monitoring Activities

ISO 27001 Annex A 8.17 Clock Synchronisation

ISO 27001 Annex A 8.18 Use of Privileged Utility Programs

ISO 27001 Annex A 8.19 Installation of Software on Operational Systems

ISO 27001 Annex A 8.20 Network Security

ISO 27001 Annex A 8.21 Security of Network Services

ISO 27001 Annex A 8.22 Segregation of Networks

ISO 27001 Annex A 8.23 Web Filtering

ISO 27001 Annex A 8.24 Use of CryptographyISO27001 Annex A 8.25 Secure Development Life Cycle

ISO 27001 Annex A 8.26 Application Security Requirements

ISO 27001 Annex A 8.27 Secure Systems Architecture and Engineering Principles

ISO 27001 Annex A 8.28 Secure Coding

ISO 27001 Annex A 8.29 Security Testing in Development and Acceptance

ISO 27001 Annex A 8.30 Outsourced Development

ISO 27001 Annex A 8.31 Separation of Development, Test and Production Environments

ISO 27001 Annex A 8.32 Change Management

ISO 27001 Annex A 8.33 Test Information

ISO 27001 Annex A 8.34 Protection of information systems during audit testing