On 19 Jul 2019, at 17.52, Patrick Cernko via dovecot <dovecot@dovecot.org> wrote: > > Hello list, hello Dovecot developers, > > this week, I discovered a serious bug in Dovecot, that lead to several broken > mails on our servers. The bug corrupts the first few characters of the mail > header during saving. On our setup, it was almost always only the very first > line of text, that was corrupted. > > The bug seems to be triggered by a bad "interaction" of attachment_dir option > and zlib plugin. If you use both, you most likely are affected, too, except > you only use zlib plugin for reading previously compressed stored mails. > That's also the workaround we use now: zlib plugin only enabled in > mail_plugins but no plugin/zlib_save set.
Actually the mail isn't saved corrupted. The bug is when reading the mail. So any existing corrupted mails become fixed after upgrading. Fix here: https://github.com/dovecot/core/commit/5068b11e594ad7cc1f7cedf2bd9280520e0e534d <https://github.com/dovecot/core/commit/5068b11e594ad7cc1f7cedf2bd9280520e0e534d>
