If not properly secured, the infrastructure and tools that run our build and delivery pipelines can become a big liability. Pipelines need access to critical data and systems like source code, credentials and secrets to build and deploy software. This makes these systems very inviting to malicious actors. We therefore highly recommend applying zero trust security for CI/CD pipelines and infrastructure — trusting them as little as necessary. This encompasses a number of techniques: If available, authenticate your pipelines with your cloud provider via federated identity mechanisms like OIDC, instead of giving them direct access to secrets. Implement the principle of least privilege by minimizing the access of individual user or runner accounts, rather than employing "god user accounts" with unlimited access. Use your runners in an ephemeral way instead of reusing them, to reduce the risk of exposing secrets from previous jobs or running jobs on compromised runners. Keep the software in your agents and runners up to date. Monitor the integrity, confidentiality and availability of your CI/CD systems the same way you would monitor your production software.
We're seeing teams forget about these types of practices particularly when they’re used to working with a self-managed CI/CD infrastructure in internal network zones. While all of these practices are important in your internal networks, they become even more crucial when using a managed service, as that extends the attack surface and blast radius even more.