Re: under some kind of attack

Am 20.07.2017 um 12:28 schrieb mj:

I have concoted something that seems to work. And for the archives, this is it:

...

failregex = auth: Info: ldap\(.+,<HOST>,.+\): invalid credentials \(given password: .+ssword\) auth: Info: ldap\(.+,<HOST>,.+\): invalid credentials \(given password: 1qaz2wsx\) auth: Info: ldap\(.+,<HOST>,.+\): invalid credentials \(given password: 123321\) auth: Info: ldap\(.+,<HOST>,.+\): invalid credentials \(given password: 1234567890\) auth: Info: ldap\(.+,<HOST>,.+\): invalid credentials \(given password: 1q2w3e4r.+\)

It's still reactive, and not pro-active.

All the other suggestions are very much appreciated, including weakforced, however implementing that is a much larger project.

i dont understand why you focused on that ldap strings fail2ban should trigger on some "Authentication failure" regex in the related syslog

perhaps this will help to make it more clear

http://www.stefan-seelmann.de/wiki/fail2ban#postfix-and-dovecot

Next I have to find out how to feed my fail2ban logs back to blocklist.de, to improve their mail.txt hit rate.

Thanks again for all kind assistance.

MJ

On 07/20/2017 11:16 AM, mj wrote:

...

Hi all,

If I may, one more question on this subject:

I would like to create a fail2ban filer, that scans for these lines:

...

Jul 20 11:10:09 auth: Info: ldap(user1,60.166.35.162,<cDFXHbxUQgA8piOi>): invalid credentials (given password: password) Jul 20 11:10:19 auth: Info: ldap(user2,61.53.66.4,): invalid credentials (given password: password)

(as you can see, I have enabled auth_verbose_passwords to do this, making me very uncomfortable...)

Anyway: since there are only a few password variations, I would like to block anyone using those passwords.

(since the connections are over TLS/SSL, I cannot use iptables, as suggested earlier)

So I need a specific fail2ban rule that extracts the <IP> from that line, and matches on "(given password: password)"

Can anyone here help out with a failregex line that would match..?

Best Regards MfG Robert Schetterer

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