sealed-secrets /v1/rotate can widen sealing scope to cluster-wide via attacker-controlled template annotations

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.