How to Install CSF (ConfigServer & Security Firewall) on cPanel

ConfigServer & Security Firewall (CSF) is getting more popularity for cPanel servers security. It prevents your server from DDOS attacks. This article will help you for installing and configuring CSF firewall on cPanel servers.

Step 1 – Install CSF Firewall

First download latest source code of CSF firewall and extract on your system using following commands.

wget https://download.configserver.com/csf.tgz
tar xfz csf.tgz 
cd csf

After extracting latest code from your system. Execute install.sh script to install CSF on your system. The installer will automatically detect for cPanel server and install required modules for it.

chmod +x install.sh
sh install.sh

Step 2 – Configure CSF Firewall

Now edit /etc/csf/csf.conf configuration file and disable TESTING mode by setting value to “0”.

TESTING = “0”

Let’s restart csf service

csf -r

Now you can visit to WHM interface Home » Plugins » ConfigServer Security & Firewall to access CSF graphical interface for more configuration options.

Step 3 – Manage CSF with Command Line

We can also manage CSF firewall using command line. For example below is some

To allow an IP. Ip will be added to /etc/csf/csf.allow

csf -a 11.22.33.44
[or]
csf --add 11.22.33.44

To deny an IP. Ip will be added to /etc/csf/csf.deny

csf -d 11.22.33.44
[or]
csf --deny 11.22.33.44

To search for specific IP, CIDR in iptables rules.

csf -g 11.22.33.44 [or] csf --grep 11.22.33.44

Start the firewall rules

csf -s [or] csf --start

Flush/Stop firewall rules (Note: lfd may restart csf)

csf -f [or] csf --stop

Restart CSF firewall rules

csf -r [or] csf --restart