The OpenPGP specification allows a Cipher Feedback Mode (CFB) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL. NOTE: third parties report that this is a problem in applications that mishandle the Modification Detection Code (MDC) feature or accept an obsolete packet type, not a problem in the OpenPGP specification

The S/MIME specification allows a Cipher Block Chaining (CBC) malleability-gadget attack that can indirectly lead to plaintext exfiltration, aka EFAIL.