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

Using extended file attributes to protect sensitive files


Extended attributes are an extensible way to store metadata in files. These are name-value pairs associated with files and directories. Several filesystems support extended file attributes that enable further customization of allowable file operations.

Getting ready

At present, in Linux there are four different namespaces for extended file attributes:

  • user
  • trusted
  • security
  • system

Many tools are available for manipulating extended attributes, and these are normally included in the attr package, which comes with most Linux distributions.

If attr is not installed in your system, simply execute the following command to install it:

sudo apt-get install attr

To check if this package is installed on our system, just run attr in the Terminal. If an output appears as shown here, it will confirm that the package is installed:

The next step is to check if the kernel has support for the attribute. It can be checked using the following command:

The output...