How to Install CSF on Ubuntu 20.04

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Introduction

Before we start discussing how to install CSF on Ubuntu 20.04, let's take a quick look at What is CSF?

CSF is a ConfigServer Security and Firewall, a popular security tool for Linux. It provides a user-friendly interface for iptables to protect Linux servers. CSF has multiple features, such as a stateful packet inspection firewall, intrusion detection, a login-failure daemon, DDOS protection, and control-panel integration.

In this tutorial, you will install CSF. We will also answer some frequently asked questions about CSF.

Features of CSF

Stateful Packet Inspection Firewall – A robust firewall that monitors inbound and outbound packets to ensure only authorized traffic is allowed.
Intrusion Detection – Alerts and logs the activities of intruders.
Login-Failure Daemon – Monitors failed login attempts, and blocks them after certain limits are reached.
DDOS Protection – Monitors DDOS and brute force attacks, and blocks them in real time.
Control Panel Integration – Easy to integrate with 3rd party control panels such as cPanel, Plesk, and DirectAdmin.

Step 1 – Deploying the Ubuntu Server

1) Deploy the new Ubuntu 20.04 instance.

2) Connect to the server through SSH as root.

Step 2 – Preparing for the CSF Installation

1) Ubuntu 20.04 comes with UFW pre-installed. To install CSF, you must first remove it with the following command:

 apt remove ufw

2) Next, install the CSF dependencies.

apt install perl zip unzip libwww-perl liblwp-protocol-https-perl

3) The CSF requires Sendmail to dispatch alerts to the administrator.

apt install sendmail-bin

Step 3 – Installing the CSF

1) Navigate to /usr/src.

cd /usr/src

2) Download the CSF distribution, by using the following command:

wget https://download.configserver.com/csf.tgz

3) Next, extract the CSF.

tar -xzf csf.tgz

4) Then, navigate to /usr/src/csf.

cd csf

5) Once you're done, execute this command:

sh install.sh

6) Verify the status of CSF after the installation is complete:

perl /usr/local/csf/bin/csftest.pl

7) Confirm that all tests report as OK. You will observe the following result:

RESULT: csf should function on this server

8) Then, verify CSF status after the installation:

csf -v

9) You'll observe the following outcomes:

csf: v14.02 (generic)
*WARNING* TESTING mode is enabled - do not forget to disable it in the configuration

Step 4 – Configuring the CSF

1) The CSF runs in TEST mode by default. To disable it, edit /etc/csf/csf.conf.

nano /etc/csf/csf.conf

2) Locate the line TESTING = 1 and change the value to 0.

TESTING = "0"

3) Locate the line RESTRICT_SYSLOG = 0 and change its value to 3. This means only members of the RESTRICT_SYSLOG_GROUP can access the syslog/rsyslog files. To do this, use the following command:

RESTRICT_SYSLOG = "3"

4) Now, save the configuration file.

5) Stop and reload the CSF using the ra option.

csf -ra

FAQs to Install CSF on Ubuntu 20.04

What's the difference between CSF and iptables?

CSF is a front-end tool that uses iptables to protect Linux servers. It provides an easy to use interface and additional features such as an Intrusion Detection System and a Login Failure Daemon. iptables is a Linux firewall that helps to filter network traffic and can be used to secure a server.

How to check the CSF firewall status?

You need SSH-login permission to the Server to start or stop CSF. Log in to the server via Terminal or Putty. Check the status of CSF by running /etc/init.d/csf status.