Book Image

Practical Linux Security Cookbook - Second Edition

By : Tajinder Kalsi
Book Image

Practical Linux Security Cookbook - Second Edition

By: Tajinder Kalsi

Overview of this book

Over the last few years, system security has gained a lot of momentum and software professionals are focusing heavily on it. Linux is often treated as a highly secure operating system. However, the reality is that Linux has its share of security ?aws, and these security ?aws allow attackers to get into your system and modify or even destroy your important data. But there’s no need to panic, since there are various mechanisms by which these ?aws can be removed, and this book will help you learn about different types of Linux security to create a more secure Linux system. With a step-by-step recipe approach, the book starts by introducing you to various threats to Linux systems. Then, this book will walk you through customizing the Linux kernel and securing local files. Next, you will move on to managing user authentication both locally and remotely and mitigating network attacks. Later, you will learn about application security and kernel vulnerabilities. You will also learn about patching Bash vulnerability, packet filtering, handling incidents, and monitoring system logs. Finally, you will learn about auditing using system services and performing vulnerability scanning on Linux. By the end of this book, you will be able to secure your Linux systems and create a robust environment.
Table of Contents (20 chapters)
Title Page
Copyright and Credits
Contributors
Packt Upsell
Preface
Index

Shorewall


Want to set up a Linux system as a firewall for a small network? Shorewall helps us to configure an enterprise-level firewall via standard Shorewall tools. Shorewall is actually built on Iptables, but it makes it easier to configure things.

Getting ready

A Linux system with two network cards installed and working is needed for configuring Shorewall. One card will be used as an external network interface and the second will be used as an internal network interface. In our example, we are using eth0 as external and eth1 as internal. Configure both cards as per the network configuration. Make sure that you are able to ping another system on the local network and also something on the external network, the internet. On this system, we will be installing the Shorewall package and then configuring it as per our requirements.

How to do it...

  1. We begin with installing Shorewall on our system using the apt-get command:
  1. Once the installation is complete, try to start Shorewall. You will get an...