similar to: Brute Force Blocking?

Another good one is http://denyhosts.sourceforge.net/ It runs as a daemon, and can either ban IP's addresses all together, or just ban certain services. -----Original Message----- From: centos-bounces at centos.org [mailto:centos-bounces at centos.org] On Behalf Of Brian Marshall Sent: Thursday, November 16, 2006 9:33 AM To: CentOS mailing list Subject: Re: [CentOS] Re: IPTables

Hi. Since this revision (appeared in 6.3) I think ipfw violates POLA. I mean "ipfw table N list" shows values of table in Internet '.' notation. A friend of mine was surprised to found Internet representation of this "optional 32-bit unsigned value". For example security/bruteblock stores unix timestamps here and AFAICS there is no possibility to come back to the

Hello! A machine I manage remotely for a friend comes under a distributed ssh break-in attack every once in a while. Annoyed (and alarmed) by the messages like: Aug 12 10:21:17 symbion sshd[4333]: Invalid user mythtv from 85.234.158.180 Aug 12 10:21:18 symbion sshd[4335]: Invalid user mythtv from 85.234.158.180 Aug 12 10:21:20 symbion sshd[4337]: Invalid user mythtv from 85.234.158.180 Aug 12

Hello! A machine I manage remotely for a friend comes under a distributed ssh break-in attack every once in a while. Annoyed (and alarmed) by the messages like: Aug 12 10:21:17 symbion sshd[4333]: Invalid user mythtv from 85.234.158.180 Aug 12 10:21:18 symbion sshd[4335]: Invalid user mythtv from 85.234.158.180 Aug 12 10:21:20 symbion sshd[4337]: Invalid user mythtv from 85.234.158.180 Aug 12

There used to be messages on this list around the time of a new release, letting people know what was happening, but that isn't happening this time. What list should the following question be directed to, if not this one? My auto-download program snagged a copy of the 5.1-RELEASE install ISO yesterday morning, but no release announcement was made. The directories exist on most, if not all

On Fri, 12 Apr 2019, mj wrote: > What we do is: use https://github.com/trick77/ipset-blacklist to block IPs > (from various existing blacklists) at the iptables level using an ipset. "www.blocklist.de" is a nifty source. Could you suggest other publically available blacklists? > That way, the known bad IPs never even talk to dovecot, but are dropped > immediately. We

I used dovecot-1.1.7 + qmail-jms1-7+ vpopmail + ... everyday , everyuser has many spams from his/her mail to his/her for example in Bulk folder there are many spam e-mails that the sender is ourselves (from mymail at mydomain to myself at mydomain) how can i prevent these types of spam -- with regards Sophia Alikhani WorkPhone: +98-21-8497057 Mobile : +98-912-3361036

fail2ban might be good for this. On 04/05/2011 01:00 PM, asterisk-users-request at lists.digium.com wrote: > > Date: Tue, 5 Apr 2011 08:44:41 -0700 (PDT) > From: Steve Edwards<asterisk.org at sedwards.com> > Subject: Re: [asterisk-users] Iptables configuration to handle brute > force registrations? > > On Tue, 5 Apr 2011, Gilles wrote: > >> I'm no expert

I've just posted this to another list where we were talking about the same old issues we've been plagues with recently - I'd already posted some iptables rules, but added more to it for this... This script probably isn't compatable with anything else, but I don't run anything else. It's also designed to act on the incoming interface, not to run in a router, but

On Thu, 11 Apr 2019 at 13:24, Marc Roos via dovecot <dovecot at dovecot.org> wrote: > > > Say for instance you have some one trying to constantly access an > account > > > Has any of you made something creative like this: > > * configure that account to allow to login with any password > * link that account to something like /dev/zero that generates infinite

Hi List, optimizing the configuration on one of our servers (which was hit by a brute force attack on dovecot) showed an odd behavior. Dovecot Version 1.0.7 (CentOS 5.2) The short story: On one of our servers an attacker did a brute force attack on dovecot (pop3). Since the attacker closed and reopened the connection after every user/password combination the logs showed many lines like

I was hoping to set up fail2ban to block IP addresses that generate too many Samba password failures, but it needs a syslog message with the IP address of the computer that failed password authentication. Unfortunately, Samba doesn't seem to do this in my environment. Here's a sample error message: smbd[312]: smb_pam_passcheck: PAM: smb_pam_auth failed - Rejecting User brutus ! I

Over the weekend one of our servers at a remote location was hammered by an IP originating in mainland China. This attack was only noteworthy in that it attempted to connect to our pop3 service. We have long had an IP throttle on ssh connections to discourage this sort of thing. But I had not considered the possibility that other services were equally at risk. Researching this on the web does

On 11/04/2019 11:43, Marc Roos via dovecot wrote: > A. With the fail2ban solution > - you 'solve' that the current ip is not able to access you It is only a solution if there are subsequent attempts from the same address. I currently have several thousand addresses blocked due to dovecot login failures. My firewall is set to log these so I can see that few repeat, those

Marc, There is a strategy loosely referred to as "choose your battles well" :-) Let the others bother with their own problems. If you can, hack the server and dump the 500GB - you'll be using resources transferring the 500GB as the other server receives it. Two servers wasting resources because you think you are punishing an offender! On Thu, 11 Apr 2019 at 13:43, Marc Roos

Hi List, optimizing the configuration on one of our servers (which was hit by a brute force attack on dovecot) showed an odd behavior. The short story: On one of our servers an attacker did a brute force attack on dovecot (pop3). Since the attacker closed and reopened the connection after every user/password combination the logs showed many lines like this: dovecot: pop3-login: Aborted

> Am 11.04.2019 um 12:43 schrieb Marc Roos via dovecot <dovecot at dovecot.org>: > > Please do not assume anything other than what is written, it is a > hypothetical situation > > > A. With the fail2ban solution > - you 'solve' that the current ip is not able to access you > - it will continue bothering other servers and admins > - you get the

Say for instance you have some one trying to constantly access an account Has any of you made something creative like this: * configure that account to allow to login with any password * link that account to something like /dev/zero that generates infinite amount of messages (maybe send an archive of virusses?) * transferring TB's of data to this harassing client. I think it would be

We have several web applications deployed under Apache that require a user id / password authentication. Some of these use htdigest and others use the application itself. Recently we have experienced several brute force attacks against some of these services which have been dealt with for the nonce by changes to iptables. However, I am not convinced that these changes are the answer. Therefore

I'm looking for a way to deny access to dovecot from certain IP addresses, basically to help prevent brute force attacks on the server. Right now I'm using denyhosts which scans /var/log/secure for authentication failures which then can add an entry to /etc/hosts.deny, but since dovecot doesn't have tcp wrappers support, that doesn't do anything. It doesn't look like I can