In this guide you will learn how to implement ISO 27001 Annex A 8.4 Access to Source Code and pass your audit from ISO 27001 Lead Auditor Stuart Barker – author of the ultimate ISO 27001 Toolkit.
ISO 27001 Annex A 8.4 Access To Source Code is an ISO 27001 control that wants you to make sure you have controls in place around access to code.
Table of contents
Key Takeaways
- ISO 27001 Annex A 8.4 requires organisations to strictly manage read and write access to their source code, development tools, and software libraries.
- The goal is to protect your Intellectual Property (IP) and, more importantly, to prevent the unauthorized introduction of “rogue” code or backdoors that could lead to a catastrophic security breach.
Purpose & Definition
The purpose of ISO 27001 Annex A 8.4 Access To Source Code is to prevent the introduction of unauthorised functionality, avoid unintentional or malicious changes and to maintain the confidentiality of valuable intellectual property.
The ISO 27001 standard defines Annex A 8.4 as:
Read and write access to source code, development tools and software libraries should be appropriately managed.
ISO 27001:2022 Annex A 8.4 Access To Source Code
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FREE ISO 27001 Annex A 8.4 Training Video
In this free training video you will learn How to implement ISO 27001 Access To Source Code (Annex A 8.4) and Pass Your Audit
ISO 27001 Annex A 8.4 Requirements and Guidance
Applicability
If you have source code then you want to protect access to it. If you do not then this is not in scope for you, you can update your statement of applicability to put it out of scope, add it to the risk register and accept the risk.
You are going to manage access to your source code, program code, libraries and associated software. The requirement is to stop unauthorised modification that can lead to an information security incident.
The Three Pillars of Implementation
The effective implementation of Annex A 8.4 is a continuous process that is built on three foundational pillars that ensure that your controls are robust, documented and resilient.
- Risk Based Foundation: assess assets and threats to implement proportionate controls
- Documented Process and Governance: formalise policies and procedures for access management
- Continuous Assurance and Monitoring: establish mechanisms for logging, monitoring and control effectiveness
Pillar 1: Risk Based Approach
- Risk Assessment: Conduct a risk assessment to identify all repositories of source code, program code, libraries and associated software.
- Threat Modelling: Understand the specific threats to each code asset.
- Proportionate controls: Implement proportionate controls based on risk.
Pillar 2: Documented Process and Governance
If you do have source code then you already know what to do as there is nothing revolutionary in this particular control. The control is looking for documentation and maturity of process of what you already do. The required documentation includes:
- ISO 27001 Access Control Policy: governs access including access to source code.
- ISO 27001 Secure Development Policy: details the requirements for source code access in the development lifecycle.
- Process and Procedural records of evidence: records of changes, updates, reviews, monitoring and logging.
Pillar 3: Assurance
You will ensure that there is ongoing assessment of the effectiveness of the controls. Activities include:
- Logging and monitoring: implement logging to create audit trails of read/write access and codebase changes
- Integrity Verification: employ digital signatures where required to provide assurance of code integrity
- Third Party Assurance: consider escrow services for high value code bases
Access Control Policy Template
Access to source code is governed by the access control policy as part of the access control process.
Secure Development Policy Template
Sets out the approach to access to source code.
How to implement ISO 27001 Annex A 8.4
A fundamental technical requirement for preventing the introduction of malicious logic and safeguarding intellectual property. By following these action-oriented steps, your organisation can establish a secure development environment that satisfies the rigorous standards of ISO 27001 Annex A 8.4.
- Formalise Source Code Access Policies
- Provision Granular IAM Roles via the Principle of Least Privilege
- Mandate Multi-Factor Authentication (MFA) and SSH Key Management
- Implement Automated Secret Scanning and Pre-Commit Hooks
- Execute Independent Peer Reviews and Pull Request Gates
- Implement Centralised Audit Logging and SIEM Integration
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How to pass the ISO 27001 Annex A 8.4 audit
- Have policies and procedures in place: Write, approve, implement and communicate the documentation required for access to source code.
- Assess your code use and code requirements and perform a risk assessment: For each code type perform a risk assessment.
- Implement controls proportionate to the risk posedBased on the risk assessment implement the appropriate controls to mitigate the risk.
- Keep records: For audit purposes you will keep records. Examples of the records to keep include changes, updates, monitoring, review and audits.
- Test the controls that you have to make sure they are working: Perform internal audits that include the testing of the controls to ensure that they are working.
Top 3 mistakes and how to avoid them
The top 3 mistakes people make for ISO 27001 Annex A 8.4 are
- Allowing everyone to access code: Depending on the size of teams, complexity and mix of internal and external resource the requirements for access restrictions on code can often get over looked. Be sure to understand and document the requirements, put in place processes and lock the access down based on organisation need and business risk.
- Your code is on laptops: This common mistake actually relates to copies of your code being all over the place. It can be hard to manage code and developers and teams to maintain a single source of truth in a controlled way that protects your intellectual property and the integrity of the code base. Some people use check in and check out solutions but be aware of rogue copies of your code out in the real world and the risk it poses to you, usually in terms of that code being taken and used some where else for commercial gain without your approval or knowledge.
- 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.
Related ISO 27001 Controls
Further Reading
ISO 27001 Controls and Attribute Values
| Control type | Information security properties | Cybersecurity concepts | Operational capabilities | Security domains |
|---|---|---|---|---|
| Preventive | Confidentiality | Protect | Identity and access management | Protection |
| Integrity | Application Security | |||
| Availability | Secure Configuration |
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