4.3. fail2ban

fail2ban can be tricky to configure correctly; with so many flavours of Linux it’s impossible to provide anything but general guidance.

4.3.1. Standard Filters

The filter files included are intended only as a starting point for those who want WPf2b to work “out of the box”.

There is no “one size fits all” configuration possible for fail2ban - what may be a soft failure for one site should be treated as a hard failure for another, and vice versa. Careful thought should be given to what is appropriate for your environment.

4.3.1.1. Typical Settings

  1. Copy wordpress-hard.conf and wordpress-soft.conf to your fail2ban/filters.d directory
  2. Create a new file in jail.d called wordpress.conf:
[wordpress-hard]
enabled = true
filter = wordpress-hard
logpath = /var/log/auth.log
maxretry = 1
port = http,https

[wordpress-soft]
enabled = true
filter = wordpress-soft
logpath = /var/log/auth.log
maxretry = 3
port = http,https

Note

Make sure you change logpath to the correct log for your OS. If your OS uses systemd it may be simpler and/or easier to install a real syslog service first.

  1. Reload or restart fail2ban

4.3.1.2. wordpress-hard.conf and wordpress-soft.conf

There are some things that are almost always malicious, e.g. blocked users and pingbacks with errors. wordpress-hard.conf is designed to catch these so that you can ban the IP immediately.

Other things are relatively benign, like a failed login. You can’t let people try forever, but banning the IP immediately would be wrong too. wordpress-soft.conf is designed to catch these so that you can set a higher retry limit before banning the IP.

For the avoidance of doubt: you should be using both filters.

4.3.2. Custom Filters

You should never modify the standard wordpress-hard.conf and wordpress-soft.conf files. Instead, copy them to, for example, wordpress-hard-custom.conf and wordpress-soft-custom.conf, and edit those.

It is very rare that individual filter rules are modified, but new rules are common; there is always an entry in the “Updating” notes when there is any change to the rules. It is your responsibility to ensure the rules in your custom filters are kept current.

4.3.2.1. wordpress-extra.conf

Version 4 introduced a number of new logging options which didn’t fit cleanly into either of the hard or soft filters - they’re extra.

For example, if your site doesn’t use WordPress comments at all, you could add the rules matching attempted comments to the hard-custom filter. Again, there is no “one size fits all” for these rules.

4.3.3. Updating

Whether you use the standard filter files or a highly-customed set of your own, it is critical they are kept up to date. There is always an entry in the “Updating” notes when the filter files need to be updated.

Obsolete filters may cause users to be blocked incorrectly, or attackers not to be detected.

WPf2b cannot update them for you.