Tech Challenge

A team stores a database password in a Kubernetes Secret (below) and concludes it is now safely encrypted inside the cluster. A security reviewer disagrees. What is actually true about how this Secret is protected, and what fix is required?

apiVersion: v1
kind: Secret
metadata:
  name: db-creds
type: Opaque
data:
  password: c3VwZXItczNjcmV0   # "super-s3cret"