Book Image

Mastering Defensive Security

By : Cesar Bravo
Book Image

Mastering Defensive Security

By: Cesar Bravo

Overview of this book

Every organization has its own data and digital assets that need to be protected against an ever-growing threat landscape that compromises the availability, integrity, and confidentiality of crucial data. Therefore, it is important to train professionals in the latest defensive security skills and tools to secure them. Mastering Defensive Security provides you with in-depth knowledge of the latest cybersecurity threats along with the best tools and techniques needed to keep your infrastructure secure. The book begins by establishing a strong foundation of cybersecurity concepts and advances to explore the latest security technologies such as Wireshark, Damn Vulnerable Web App (DVWA), Burp Suite, OpenVAS, and Nmap, hardware threats such as a weaponized Raspberry Pi, and hardening techniques for Unix, Windows, web applications, and cloud infrastructures. As you make progress through the chapters, you'll get to grips with several advanced techniques such as malware analysis, security automation, computer forensics, and vulnerability assessment, which will help you to leverage pentesting for security. By the end of this book, you'll have become familiar with creating your own defensive security tools using IoT devices and developed advanced defensive security skills.
Table of Contents (23 chapters)
Section 1: Mastering Defensive Security Concepts
Section 2: Applying Defensive Security
Section 3: Deep Dive into Defensive Security

Enhancing the protection of the server by improving your access controls

ACLs enable Unix administrators to apply detailed fine-tuning of permissions that may not be possible to achieve with the commands specified in the previous section. Therefore, let's explore how to work with ACLs so that you can take advantage of them to enhance the application and management of permissions.

Viewing ACLs

First, you can use the getfacl {file_name} command to see the ACL of the specified file.

The following figure shows an example of a file with and without an ACL. Notice that, when the file has an ACL, it adds a new line with the permissions of the specified user on the ACL, in this case, the cesar user and their associated permissions (rwx):

Figure 7.19 – View of the getfacl command

You can also identify whether a file has an ACL by doing a long listing (ls –l):

Figure 7.20 – Listing of a file with an ACL