Fail2ban scans log files like /var/log/pwdfail or /var/log/apache/error_log and bans IP that makes too many password failures. It updates firewall rules to reject the IP address.

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10
votes
5answers
5k views

Is it worth the effort to block failed login attempts

Is it worthwhile running fail2ban, sshdfilter or similar tools, which blacklist IP addresses which attempt and fail to login? I've seen it argued that this is security theatre on a "properly secured"...
6
votes
2answers
7k views

Custom fail2ban Filter for phpMyadmin bruteforce attempts

In my quest to block excessive failed phpMyAdmin login attempts with fail2ban, I've created a script that logs said failed attempts to a file: /var/log/phpmyadmin_auth.log Custom log The format of ...
0
votes
1answer
415 views

How to mitigate DDOS attacks on AWS?

I have web application (NodeJS) and I plan to deploy it to AWS. To minimize the cost it will run on single EC2 instance. I'm worried though about what will happen if someone decides to bless me with ...
-1
votes
1answer
556 views

iptables: REJECT not working, but DROP does

I have recently setup a server with fail2ban, and it is mostly working except I am getting errors whenever this command tries to execute: sudo iptables -D fail2ban-ssh -s xxx.xxx.xxx.xxx -j REJECT --...
66
votes
8answers
119k views

How to Unban an IP properly with Fail2Ban

I'm using Fail2Ban on a server and I'm wondering how to unban an IP properly. I know I can work with IPTables directly: iptables -D fail2ban-ssh <number> But is there not a way to do it with ...
23
votes
4answers
20k views

Permanent block of IP after n retries using fail2ban

I have a fail2ban configured like below: block the ip after 3 failed attempts release the IP after 300 sec timeout This works perfectly and I want to keep it this way such that a valid user gets a ...
6
votes
1answer
2k views

measures to take against a dns amplification attack

I recently discovered that my server was being used as part of a DNS DDOS. Basically, my BIND setup allowed recursion, and it was used to attack a certain IP address using IP spoofing. I took the ...
2
votes
1answer
12k views

How To use fail2ban for Nginx? [closed]

How can I use fail2ban on an Nginx server? What are the rules to put in the jails.conf?
9
votes
4answers
20k views

In Fail2Ban, How to Change the SSH port number?

In my server, the ssh port is not the standard 22. I have set a different one. If I setup fail2ban, will it be able to detect that port? How can I tell it to check that port rather than port 22? The ...
11
votes
2answers
8k views

How do I setup monitoring of MySQL with Fail2ban?

Searching the internet with search engines on MySQL and fail2ban yields lots of results on putting your fail2ban logs into MySQL, however I'm wanting to monitor failed MySQL attempts to log in and ban ...
4
votes
4answers
968 views

fail2ban bans me after a series of *successful* logins

I created a passwordless ssh login for one of my servers by using the authorized_keys file. The server has fail2ban on it, and I noticed that after several successful logins I could no longer log in (...
3
votes
4answers
711 views

Protect ssh server

I've got a debian-machine running several services, like apache with http and https, jabber and an openssh server for administration. The ssh-server is not running on port 22. It's on something like ...
5
votes
6answers
3k views

fail2ban and denyhosts constantly ban me on Ubuntu

I just got an Ubuntu instance on Linode. To secure the SSH on it, I installed fail2ban (using apt-get), but then had a problem: fail2ban kept banning my IP (for limited durations, thankfully) even ...
4
votes
4answers
4k views

Fail2Ban on CentOS 6.5 Never Bans

Environment: *CentOS 6.5 *Fail2Ban 0.8.14-1 *date outputs the correct date Behavior: Fail2ban starts successfully, but does not create iptables blocks after bad SSH login attempts. I'm only concerned ...
2
votes
3answers
4k views

Why isn't fail2ban blocking failures?

This below is the output of fail2ban log. Nothing more shows up, but in auth.log I see like hundreds of failures for root user login (someone is bad ass brute forcing). 2011-07-06 01:48:16,249 ...
1
vote
1answer
674 views

Fail2ban configuration for nginx using firewallcmd in CentOS 7

Previously I have a CentOS 6.5 with Iptables and I configure some jails for nginx as suggested here: How To use fail2ban for Nginx?. But now I am in CentOS 7, trying to use the new firewall and ...