Improper Access Control

Summary

External Secrets Operator is a Kubernetes operator that integrates external secret management systems. From version 0.15.0 through 0.19.1, a vulnerability was discovered where the "List()" calls for Kubernetes Secret and SecretStore resources performed by the "PushSecret" controller did not apply a namespace selector. This flaw allowed an attacker to use label selectors to list and read secrets/secret-stores across the cluster, bypassing intended namespace restrictions. An attacker with the ability to create or update "PushSecret" resources and control "SecretStore" configurations could exploit this vulnerability to exfiltrate sensitive data from arbitrary namespaces. This could lead to full disclosure of Kubernetes secrets, including credentials, tokens, and other sensitive information stored in the cluster. A workaround for this issue includes auditing and restricting RBAC permissions so that only trusted service accounts can create or update "PushSecret and SecretStore" resources.