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

Good Morning List,

just a short question to this vulnerability. We are using a setup with dovecot
redirector/proxy frontend servers
and some backend server, which store the mailboxes. 
Is it anough to update the frontend servers if I like to fix the the
vulnerability?

greetings,
Oliver

> On 2 Sep 2019, at 11.01, MK via dovecot <dovecot at dovecot.org>
wrote:
> 
> Good Morning List,
> 
> just a short question to this vulnerability. We are using a setup with
dovecot redirector/proxy frontend servers
> and some backend server, which store the mailboxes. 
> Is it anough to update the frontend servers if I like to fix the the
vulnerability?
No. 

Sami

>> On 2 Sep 2019, at 11.01, MK via dovecot <dovecot at dovecot.org>
wrote:
>> 
>> Good Morning List,
>> 
>> just a short question to this vulnerability. We are using a setup with
dovecot redirector/proxy frontend servers
>> and some backend server, which store the mailboxes. 
>> Is it anough to update the frontend servers if I like to fix the the
vulnerability?
>No. 
>
>Sami
Thanks. Do I understand this correct that updating the frontends fixes only the
vulnerability for anonymous requests
and for users logged in the vulnerability still exists if I don't update the
backend servers?

Oliver