Summary
A vulnerability was discovered in the External Secrets Operator 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.
Impact
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.
Exploitability
To exploit this vulnerability, an attacker must:
- Have permissions to create or update
PushSecret
resources.
- Control one or more
SecretStore
resources.
With these conditions met, the attacker could leverage label selectors to list secrets from any namespace and retrieve their contents.
Affected Versions
- Vulnerable: v0.15.0 – v0.19.1
- Not Vulnerable: v0.19.2 and later
Fix
The vulnerability was addressed in v0.19.2 by adding namespace restrictions to the List()
calls for both PushSecret
and SecretStore
controllers.
This ensures that only secrets in the intended namespace are accessible.
Relevant fixes:
- #5133 – Enforce namespace selector for PushSecret
List()
calls
- #5109 – Enforce namespace selector for SecretStore
List()
calls
Mitigation
If upgrading to v0.19.2 or later is not immediately possible, the following mitigations are recommended:
- Restrict RBAC permissions so that only trusted service accounts can create or update
PushSecret
and SecretStore
resources.
- Audit existing
PushSecret
and SecretStore
resources to ensure they are controlled by trusted parties.
- Review Network Policies to prevent data exfiltration
Credit
This vulnerability was reported by @gracedo and @moolen
References
Summary
A vulnerability was discovered in the External Secrets Operator where the
List()
calls for Kubernetes Secret and SecretStore resources performed by thePushSecret
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.
Impact
An attacker with the ability to create or update
PushSecret
resources and controlSecretStore
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.
Exploitability
To exploit this vulnerability, an attacker must:
PushSecret
resources.SecretStore
resources.With these conditions met, the attacker could leverage label selectors to list secrets from any namespace and retrieve their contents.
Affected Versions
Fix
The vulnerability was addressed in v0.19.2 by adding namespace restrictions to the
List()
calls for bothPushSecret
andSecretStore
controllers.This ensures that only secrets in the intended namespace are accessible.
Relevant fixes:
List()
callsList()
callsMitigation
If upgrading to v0.19.2 or later is not immediately possible, the following mitigations are recommended:
PushSecret
andSecretStore
resources.PushSecret
andSecretStore
resources to ensure they are controlled by trusted parties.Credit
This vulnerability was reported by @gracedo and @moolen
References