Sealed Secrets

A security vulnerability exists in the Sealed Secrets controller's unauthenticated POST endpoints. By submitting a modified payload containing custom Go template logic in spec.template.data, an attacker with internal network access can abuse the handler as a decryption oracle to recover the full plaintext of any sealed secret. The POST /v1/verify and /v1/rotate handlers call Unseal() to decrypt target secrets, then render any Go templates found in spec.template.data.* using the decrypted payload as the evaluation context (pkg/apis/sealedsecrets/v1alpha1/sealedsecret_expansion.go). Errors encountered during template execution are directly reflected in the resulting HTTP response status codes. Missing AEAD label binding: the spec.template.data field is omitted from the AEAD authenticated-data label binding ciphertext to metadata. As a result, an attacker can copy a target's valid metadata and encryptedData verbatim, satisfying AEAD decryption and label validation, while freely replacing spec.template.data with arbitrary template logic. Side-channel oracle: template execution errors map directly to HTTP response codes. HTTP 200 (OK) indicates template execution succeeded; HTTP 409 (Conflict) indicates template execution failed (e.g. via {{ fail "..." }}). By injecting conditional statements such as {{ if eq (substr 0 1 .password) "S" }}ok{{ else }}{{ fail "x" }}{{ end }}, an attacker receives an HTTP 200 status when a character guess is correct and an HTTP 409 when it is incorrect. This differential response leaks one character-equality bit per request, allowing full secret extraction over successive queries. Attack vector & prerequisites: unauthenticated; requires network access to the controller's internal service port (:8080). Although this service is not exposed to the public internet by default, it is accessible to any pod within the Kubernetes cluster or via a kubectl port-forward connection.

Published: 2026-09-15T09:16:59.460Z
Updated: 2026-09-16T11:53:25.201Z

Bitnami Sealed Secrets is vulnerable to a scope-widening attack during the secret rotation (/v1/rotate) flow. The rotation handler derives the sealing scope for the newly encrypted output from untrusted spec.template.metadata.annotations present in the input SealedSecret. By submitting a victim SealedSecret to the rotate endpoint with the annotation sealedsecrets.bitnami.com/cluster-wide=true injected into the template metadata, a remote attacker can obtain a rotated version of the secret that is cluster-wide. This bypasses original "strict" or "namespace-wide" constraints, allowing the attacker to retarget and unseal the secret in any namespace or under any name to recover the plaintext credentials.

Published: 2026-02-26T00:50:00.863Z
Updated: 2026-02-26T15:58:32.372Z