Book Image

SELinux System Administration. - Second Edition

Book Image

SELinux System Administration. - Second Edition

Overview of this book

Do you have the crucial job of protecting your private and company systems from malicious attacks and undefined application behavior? Are you looking to secure your Linux systems with improved access controls? Look no further, intrepid administrator! This book will show you how to enhance your system’s secure state across Linux distributions, helping you keep application vulnerabilities at bay. This book covers the core SELinux concepts and shows you how to leverage SELinux to improve the protection measures of a Linux system. You will learn the SELinux fundamentals and all of SELinux’s configuration handles including conditional policies, constraints, policy types, and audit capabilities. These topics are paired with genuine examples of situations and issues you may come across as an administrator. In addition, you will learn how to further harden the virtualization offering of both libvirt (sVirt) and Docker through SELinux. By the end of the book you will know how SELinux works and how you can tune it to meet your needs.
Table of Contents (16 chapters)
SELinux System Administration - Second Edition
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface

Securing shell services


Another infrastructural service that is security sensitive is a shell service. Whereas malicious individuals would be happy to get remote command execution (RCE) vulnerabilities on systems to exploit, shell services immediately provide an interactive environment. Of course, securing shell services is an important strategy for administrators.

Splitting SSH over multiple instances

One potential approach to harden a shell-service-providing server is to split the access for administrators and users.

The user-facing SSH server could possibly require just user ID and password authentication or key-based authentication. It'll be running on the default port 22 and perhaps enables chrooted SSH so that the regular users do not have access to the entire file system but only a particular location, such as /var/jail. Additional safeguarding approaches such as enabling a service like fail2ban (which checks the logs for the IP addresses that are trying a brute-force attack against...