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

Other well-known Linux vulnerabilities


With time, Linux has gained a lot of popularity due to its open source nature. However, it has also resulted into increased security concerns. Linux systems tend to be as vulnerable as other operating systems, such as Windows. These vulnerabilities may be due to faults in the OS, or due to oversight by the Linux administrators.

How to do it...

In this section, we will see discuss about few of the most common Linux vulnerabilities, as follows:

  1. Linux Kernel netfilter: xt_TCPMSS: Even though it's an old vulnerability, affecting Linux kernels before 4.11, and 4.9.x before 4.9.36, it still exists in many systems of organizations that have failed to attend to this vulnerability and are still using older versions of the Linux kernel. It has CVE ID: CVE-2017-18017 and a critical vulnerability score of 9.8.
  2. If exploited successfully, the aforementioned vulnerability can help hackers send through a flood of communications and cause a denial-of-service (DoS) attack...