Book Image

Mastering Linux Security and Hardening - Second Edition

By : Donald A. Tevault
Book Image

Mastering Linux Security and Hardening - Second Edition

By: Donald A. Tevault

Overview of this book

From creating networks and servers to automating the entire working environment, Linux has been extremely popular with system administrators for the last couple of decades. However, security has always been a major concern. With limited resources available in the Linux security domain, this book will be an invaluable guide in helping you get your Linux systems properly secured. Complete with in-depth explanations of essential concepts, practical examples, and self-assessment questions, this book begins by helping you set up a practice lab environment and takes you through the core functionalities of securing Linux. You'll practice various Linux hardening techniques and advance to setting up a locked-down Linux server. As you progress, you will also learn how to create user accounts with appropriate privilege levels, protect sensitive data by setting permissions and encryption, and configure a firewall. The book will help you set up mandatory access control, system auditing, security profiles, and kernel hardening, and finally cover best practices and troubleshooting techniques to secure your Linux environment efficiently. By the end of this Linux security book, you will be able to confidently set up a Linux server that will be much harder for malicious actors to compromise.
Table of Contents (20 chapters)
1
Section 1: Setting up a Secure Linux System
8
Section 2: Mastering File and Directory Access Control (DAC)
11
Section 3: Advanced System Hardening Techniques

An overview of iptables

A common misconception is that iptables is the name of the Linux firewall. In reality, the name of the Linux firewall is netfilter, and every Linux distro has it built in. What we know is that iptables is just one of several command-line utilities that we can use to manage netfilter. It was originally introduced as a feature of Linux kernel version 2.6, so it's been around for a long time. With iptables, you do have a few advantages:

  • It's been around long enough that most Linux admins already know how to use it.
  • It's easy to use iptables commands in shell scripts to create your own custom firewall configuration.
  • It has great flexibility in that you can use it to set up a simple port filter, a router, or a virtual private network.
  • It comes pre-installed on pretty much every Linux distro, although most distros don't come with it preconfigured...