LibEtPan through 1.9.4, as used in MailCore 2 through 0.6.3 and other products, has a STARTTLS buffering issue that affects IMAP, SMTP, and POP3. When a server sends a "begin TLS" response, the client reads additional data (e.g., from a meddler-in-the-middle attacker) and evaluates it in a TLS context, aka "response injection."
| Software | From | Fixed in |
|---|---|---|
| libetpan_project / libetpan | - | 1.9.4.x |
| libmailcore / mailcore2 | - | 0.6.3.x |
| fedoraproject / fedora | 31 | 31.x |
| fedoraproject / fedora | 32 | 32.x |
| debian / debian_linux | 9.0 | 9.0.x |