Application Security Checklist [page]deterministic

This checklist aims to provide basic guidelines on securing applications running in Kubernetes from a developer's perspective. This list is not meant to be exhaustive and is intended to evolve over time.

On how to read and use this document:

• The order of topics does not reflect an order of priority.
• Some checklist items are detailed in the paragraph below the list of each section.
• This checklist assumes that a `developer` is a Kubernetes cluster user who interacts with namespaced scope objects.

> Caution: Checklists are not sufficient for attaining a good security posture on their own. A good security posture requires constant attention and improvement, but a checklist can be the first step on the never-ending journey towards security preparedness. Some recommendations in this checklist may be too restrictive or too lax for your specific security needs. Since Kubernetes security is not "one size fits all", each category of checklist items should be evaluated on its merits.

## Base security hardening

The following checklist provides base security hardening recommendations that would apply to most applications deploying to Kubernetes.

### Application design

• [ ] Follow the right [security principles](https://www.cncf.io/wp-content/uploads/2022/06/CNCF_cloud-native-security-whitepaper-May2022-v2.pdf) when designing applications.
• [ ] Application configured with appropriate [QoS class](#gloss:QoS-class) through resource request and limits. - [ ] Memory limit is set for the workloads with a limit equal to or greater than the request. - [ ] CPU limit might be set on sensitive workloads.

### Service account

• [ ] Avoid using the `default` ServiceAccount. Instead, create ServiceAccounts for each workload or microservice.
• [ ] `automountServiceAccountToken` should be set to `false` unless the pod specifically requires access to the Kubernetes API to operate.

### Pod-level `securityContext` recommendations {#security-context-pod}

• [ ] Set `runAsNonRoot: true`.
• [ ] Configure the container to execute as a less privileged user (for example, using `runAsUser` and `runAsGroup`), and configure appropriate permissions on files or directories inside the container image.
• [ ] Optionally add a supplementary group with `fsGroup` to access persistent volumes.
• [ ] The application deploys into a namespace that enforces an appropriate [Pod security standard](/docs/concepts/security/pod-security-standards/). If you cannot control this enforcement for the cluster(s) where the application is deployed, take this into account either through documentation or additional defense in depth.

### Container-level `securityContext` recommendations {#security-context-container}

• [ ] Disable privilege escalations using `allowPrivilegeEscalation: false`.
• [ ] Configure the root filesystem to be read-only with `readOnlyRootFilesystem: true`.
• [ ] Avoid running privileged containers (set `privileged: false`).
• [ ] Drop all capabilities from the containers and add back only specific ones that are needed for operation of the container.

### Role Based Access Control (RBAC) {#rbac}

• [ ] Permissions such as create, patch, update and delete should be only granted if necessary.
• [ ] Avoid creating RBAC permissions to create or update roles which can lead to [privilege escalation](/docs/reference/access-authn-authz/rbac/#privilege-escalation-prevention-and-bootstrapping).
• [ ] Review bindings for the `system:unauthenticated` group and remove them where possible, as this gives access to anyone who can contact the API server at a network level.

The create, update and delete verbs should be permitted judiciously. The patch verb if allowed on a Namespace can [allow users to update labels on the namespace or deployments](/docs/concepts/security/rbac-good-practices/#namespace-modification) which can increase the attack surface.

For sensitive workloads, consider pro …(trimmed)