The integrity check feature in OpenPGP, when handling a message that was encrypted using cipher feedback (CFB) mode, allows remote attacker…

The integrity check feature in OpenPGP, when handling a message that was encrypted using cipher feedback (CFB) mode, allows remote attackers to recover part of the plaintext via a chosen-ciphertext attack when the first 2 bytes of a message block are known, and an oracle or other mechanism is available to determine whether an integrity check failed.