Event Information

Meaning

  • The “Write below etc” event in a Kubernetes cluster indicates that a process running within a container is attempting to write or modify files below the “/etc” directory.
  • This event could potentially indicate unauthorized access or tampering with critical system configuration files.
  • To investigate further, you can use the following kubectl command to check the logs of the container where the event occurred: kubectl logs <pod_name> -c <container_name>.

Remediation

  1. Restrict Write Access to /etc Directory:
    • Modify the pod’s security context to ensure that the /etc directory is not writable. This can be done by setting the root filesystem to read-only or configuring specific volume mounts.
     apiVersion: v1
     kind: Pod
     metadata:
     name: secure-pod
     spec:
     containers:
     - name: secure-container
         image: <your-image>
         securityContext:
         readOnlyRootFilesystem: true
    
  2. Use Read-Only ConfigMaps or Secrets:
    • If your application needs to use configuration files, consider using ConfigMaps or Secrets with read-only access to provide these files. Create a ConfigMap or Secret and mount it as read-only.
     apiVersion: v1
     kind: ConfigMap
     metadata:
     name: app-config
     data:
     etc-config: |
         # Configuration data
     ---
     apiVersion: v1
     kind: Pod
     metadata:
     name: secure-pod
     spec:
     containers:
     - name: secure-container
         image: <your-image>
         volumeMounts:
         - name: config-volume
         mountPath: /etc/app-config
         readOnly: true
     volumes:
     - name: config-volume
         configMap:
         name: app-config
    

Note: The specific details of the remediation script will depend on the exact nature of the event and the desired remediation action.