Hi Guys,
I was really hoping a couple of years later this would be addressed...
I'm running Dovecot 2.2.5 on FreeBSD.
Is there anyway to limit the number of auth attempts allowed in a
single session? The reason for this is because I have "fail2ban" setup
to firewall out any IP addresses that repeatedly auth fails. The issue
occurs when the connection is already in an "established" state and the
attacker uses the existing session to hammer away, fail2ban becomes
ineffective as dovecot appears to allow the person to attempt
authentication ad infinitum.
It would be nice if there was config option that would for example
cause the software to close the connection after X failed attempts. I
use "pf" as the firewall on FreeBSD.
Unless there was some command I could have fail2ban run a command that
would destroy any tcp sessions in an established state prior to adding
the offending IP to the block list, that would be the only way around
the problem. Ideally it would be nice for dovecot have an option to
control the number of failed auth attempts.
Any suggestions?
Cheers,
Alex.
