Implement strong authorization mechanisms

Strong authorization ensures that users only have access to the resources and actions that are necessary for their job functions and responsibilities, and nothing more.
This can be achieved through proper access controls, such as role-based access control (RBAC) or attribute-based access control (ABAC), which define fine-grained permissions and privileges for users, groups, and repositories in the SCM system.
Regularly review user permissions and remove all unnecessary permissions for specific users.

Applies to

T0199 Secret leak
T0135 Vulnerable CICD system
T0140 Harvest tokens from environment variables
T0143 External user accounts
T0149 Delete repositories
T0134 Add user
T0139 Resource hijacking
T0173 Auto merge rules in SCM
T0184 Harvesting sensitive information from files
T0137 Weak authentication methods
T0186 Source code leak
T0121 Compromised legitimate artifact

References

https://docs.gitlab.com/ee/user/permissions.html
https://docs.github.com/en/organizations/managing-user-access-to-your-organizations-repositories/repository-roles-for-an-organization