[Dovecot] limiting number of incorrect logins per connection

Robert Schetterer robert at schetterer.org
Fri Aug 26 10:59:26 EEST 2011

Am 26.08.2011 09:25, schrieb Alex:
> Hi Guys,
> Running Dovecot 2 on my server. It is regularly getting dictionary auth
> attacked. What I have noticed is that once connected to a pop3/imap
> login session, you can send endless incorrect usernames+passwords
> attempts. This is a problem for me... I use fail2ban to try and stop
> these script kiddies. The problem is that fail2ban detects the bad
> auths, firewalls the IP, however, since it's an "established" session,
> the attacker can keep authing away... It's only on a subsequent (new)
> connection that the firewalling will take effect.
> Why is there no configuration option such as "max auth attempts per
> connection"? This would be useful, so once the limit is reached, the
> connection is dropped.
> is there a patch/workaround?

there where equal questions in the past
i.e read

Best Regards

MfG Robert Schetterer


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