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

Setting and enforcing password and account expiration

Something you never want is to have unused user accounts remain active. There have been incidents where an administrator set up user accounts for temporary usage, such as for a conference, and then just forgot about them after the accounts were no longer needed.

Another example would be if your company were to hire contract workers whose contract expires on a specific date. Allowing those accounts to remain active and accessible after the temporary employees leave the company would be a huge security problem. In cases like these, you want a way to ensure that temporary user accounts aren’t forgotten about when they’re no longer needed. If your employer subscribes to the conventional wisdom that users should change their passwords on a regular basis, then you’ll also want to ensure that it gets done.

Password expiration data and account expiration data are two different things. They can be set either...