Affected versions of MISP do not enforce parent-event visibility when serving cryptographic keys through CryptographicKeysController::view().
The vulnerable handler queried CryptographicKey directly using the supplied key ID and selected sensitive fields such as:
-
type
-
key_data
-
fingerprint
but did not fetch or authorize the associated parent event first.
The upstream commit explicitly states that cryptographicKeys/view could return a protected event’s signing key to any authenticated user.
The fix adds parent_id and parent_type to the lookup and then enforces authorization through the associated event using fetchSimpleEvent($user, parent_id). If the parent is not an Event, access is limited to site administrators.
Version affected: ≤2.5.45