Book Image

Practical Linux Security Cookbook

By : Michael A Lindner, Tajinder Kalsi
Book Image

Practical Linux Security Cookbook

By: Michael A Lindner, Tajinder Kalsi

Overview of this book

With the growing popularity of Linux, more and more administrators have started moving to the system to create networks or servers for any task. This also makes Linux the first choice for any attacker now. Due to the lack of information about security-related attacks, administrators now face issues in dealing with these attackers as quickly as possible. Learning about the different types of Linux security will help create a more secure Linux system. Whether you are new to Linux administration or experienced, this book will provide you with the skills to make systems more secure. With lots of step-by-step recipes, the book starts by introducing you to various threats to Linux systems. You then get to walk through customizing the Linux kernel and securing local files. Next you will move on to manage user authentication locally and remotely and also mitigate network attacks. Finally, you will learn to patch bash vulnerability and monitor system logs for security. With several screenshots in each example, the book will supply a great learning experience and help you create more secure Linux systems.
Table of Contents (17 chapters)
Practical Linux Security Cookbook
Credits
About the Author
About the Reviewer
www.PacktPub.com
Preface
Index

Shellshock's security issues


In this era where almost everything is online, online security is a major concern. These days, a lot of web servers, web-connected devices, and services use Linux as their platform. Most versions of Linux use the Unix bash shell, so the Shellshock vulnerability can affect a huge number of websites and web servers.

In the previous recipe, we took a look at the details of the Shellshock vulnerability. Now, we will understand how this bug can be exploited through SSH.

Getting Ready

To exploit the Shellshock vulnerability, we need two systems. The first system will be used as a victim and should be vulnerable to Shellshock. In our case, we will use an Ubuntu system as the vulnerable system. The second system will be used as an attacker and can have any Linux version running on it. In our case, we will run Kali on the second system.

The victim system will run the openssH-server package. It can be installed using this command:

apt-get install openssh-server

We will configure...