Book Image

Mastering Linux Security and Hardening - Third Edition

By : Donald A. Tevault
3.7 (7)
Book Image

Mastering Linux Security and Hardening - Third Edition

3.7 (7)
By: Donald A. Tevault

Overview of this book

The third edition of Mastering Linux Security and Hardening is an updated, comprehensive introduction to implementing the latest Linux security measures, using the latest versions of Ubuntu and AlmaLinux. In this new edition, you will learn how to set up a practice lab, create user accounts with appropriate privilege levels, protect sensitive data with permissions settings and encryption, and configure a firewall with the newest firewall technologies. You’ll also explore how to use sudo to set up administrative accounts with only the privileges required to do a specific job, and you’ll get a peek at the new sudo features that have been added over the past couple of years. You’ll also see updated information on how to set up a local certificate authority for both Ubuntu and AlmaLinux, as well as how to automate system auditing. Other important skills that you’ll learn include how to automatically harden systems with OpenSCAP, audit systems with auditd, harden the Linux kernel configuration, protect your systems from malware, and perform vulnerability scans of your systems. As a bonus, you’ll see how to use Security Onion to set up an Intrusion Detection System. By the end of this new edition, you will confidently be able to set up a Linux server that will be secure and harder for malicious actors to compromise.
Table of Contents (22 chapters)
1
Section 1: Setting up a Secure Linux System
9
Section 2: Mastering File and Directory Access Control (DAC)
12
Section 3: Advanced System Hardening Techniques
20
Other Books You May Enjoy
21
Index

Locking user accounts

Okay, you’ve just seen how to have Linux automatically lock user accounts that are under attack. There will also be times when you’ll want manually lock out user accounts. Let’s look at a few examples:

  • When a user goes on vacation and you want to ensure that nobody monkeys around with that user’s account while he or she is gone
  • When a user is under investigation for questionable activities
  • When a user leaves the company

With regard to the last point, you may be asking yourself, Why can’t we just delete the accounts of people who are no longer working here? And, you certainly can, easily enough. However, before you do so, you’ll need to check with your local laws to make sure that you don’t get yourself into deep trouble. Here in the United States, for example, we have the Sarbanes-Oxley law, which restricts what files publicly traded companies can delete from their computers. If...