Quoting efail.de: > However, we found that several clients only gave a warning to the user for invalid MDCs, but still displayed the modified plaintext. This a

Quoting efail.de: > However, we found that several clients only gave a warning to the user for invalid MDCs, but still displayed the modified plaintext. This allowed the CFB gadget attack despite the MDC No, the problem was that clients would render a plaintext known to have been tampered with. This was exacerbated by a zero click gadget, but would still have been an issue if images weren't loaded and a malicious link was clicked. You're right that Gpg wasn't shown to be broken, but pgp was. (This is the CBC attack, not the direct attacks on clients which are just client bugs, which themselves aren't direct evidence that a protocol is broken)