Access to Source Code - ISO 27001 Annex A Control
ISO 27001 Annex A 8.4
Source code is intellectual property and a target - protect it like both.
ISO 27001 Annex A 8.4 - Access to Source Code
Source code is a sensitive asset for any organisation that develops software. Read access exposes intellectual property and reveals security details that attackers can exploit. Write access lets someone change what the application does - whether to fix a bug, add a feature, or insert a backdoor. The control asks for both to be managed deliberately.
Modern development typically uses a code repository (Git, for example) with branch protection rules, code review requirements and integration with build pipelines. The repository becomes the central control point: who can read, who can commit, who can merge to protected branches, and how changes flow through to production. Configuring these controls properly puts most of the policy into effect technically.
Beyond the repository, the control covers development tools, build systems, package managers and the libraries pulled in from external sources. Each is a route by which malicious code could enter the application. Managing access to the build pipeline and reviewing dependencies is part of the same protective scope.
The most common gap in source code access control is the leaver who keeps repository access for weeks after their last day. Repository access often sits in a different system from the main identity provider and gets missed in standard offboarding. The fix is to bring repository access under the central identity arrangements so that one offboarding action covers everything.
Practical Compliance Guidance
Source code access management is described in the IMS1 Manual in Section 8.2 alongside the Access Control Policy. Repository configuration and code review records can support this control.
| alphaZ document | How to use it |
|---|---|
| ISO 27001 Toolkit | The full alphaZ ISO 27001 toolkit including the IMS1 Manual, policies, procedures, registers and audit checklists. |
| PP-8-100 Information Security Policy Procedure | Contains the Access Control Policy including the rules for code repository access and the development environment. Use as the source for source code governance. |
Note - all the above files can be downloaded with an alphaZ subscription.
