[Dovecot] Fail2ban

[John]

On 6/10/2010 5:38 PM, fakessh wrote:
> hi dovecot network
>
> the principle of fail2ban is repeated for connections with the same login
> fail2ban does not work if the attack changes to login every time
> this type of attack is rather to find valid user accounts
>
>
> I may be wrong, I hope I too am a victim of this kind of attacks
>
>
> On Thu, 10 Jun 2010 17:19:24 -0400, Jerrale Gayle
> <jerralegayle at sheltoncomputers.com>  wrote:
>    
>> I have fail2ban working for EVERYTHING else except dovecot. I have tried
>>      
>    
>> using my own custom regex in conjunction with the regex on the
>> dovecot.org site. Neither are picked up by fail2ban and I'm trying to
>> use an imminent attack agaist dovecot, going on now, to my advantage to
>> see when I get the right regexp. Here are my current ones:
>>
>> failregex = .*dovecot: (?:pop3-login|imap-login):
>> (?:Disconnected|Aborted login)  \((?:auth failed, .* attempts|no auth
>> attempts)\):.*rip=<HOST>,.*<<<  this is my custom
>>               (?: pop3-login|imap-login): (?:Authentication
>> failure|Aborted login \(auth failed|Aborted login \(tried to use
>> disabled|Disconnected \(auth failed).*rip=(?P<host>\S*),.*<<<  from
>> dovecot.org
>>               .*warning:.\S*\[(?P<host>)\]:
>> SASL.(?:PLAIN|LOGIN).authentication failed:.*
>>
>> Here is the current attack:
>>
>> Jun 10 17:18:10 mail dovecot: pop3-login: Disconnected (auth failed, 1
>> attempts): user=<rahul>, method=PLAIN, rip=113.12.82.71,
>>      
> lip=173.50.101.12
>    
>>
>> Can someone help me out a little?
>>
>> Thanks,
>>
>> Jerrale G
>>      
WRONG: With regexp, you can have fail2ban ignore any part of the log 
file, as in ANYTHING containing text around anything will be caught. You 
can have fail2ban ban every ip address that shows up in the log!