CVE-2019-11500: Critical vulnerability in Dovecot and Pigeonhole

[Daniel Lange]

Am 30.08.19 um 10:00 schrieb Christian Balzer via dovecot:
> When upgrading on Debian Stretch with the security fix packages all
> dovecot processes get killed and then restarted despite having
> "shutdown_clients = no" set.

This is systemd doing its "magic" (kill all control group processes), 
see https://dovecot.org/pipermail/dovecot/2016-June/104546.html
for a potential fix.