Linux

Red Hat Enterprise Linux 6
Security Guide
A Guide to Securing Red Hat Enterprise Linux

Security Guide

Red Hat Enterprise Linux 6 Security Guide
A Guide to Securing Red Hat Enterprise Linux
Edition 3
Author
Copyright © 2011 Red Hat, Inc.
Based on the Fedora Security Guide (current version at http://docs.fedoraproject.org/en-US/
Fedora/16/html/Security_Guide/index.html), written byJohnray Fuller, Eric Christensen, Adam Ligas,
and other Fedora Project contributors.
The text of and illustrations in this document are licensed by Red Hat under a Creative Commons
Attribution–Share Alike 3.0 Unported license ("CC-BY-SA"). An explanation of CC-BY-SA is available
at http://creativecommons.org/licenses/by-sa/3.0/. In accordance with CC-BY-SA, if you distribute this
document oran adaptation of it, you must provide the URL for the original version.
Red Hat, as the licensor of this document, waives the right to enforce, and agrees not to assert,
Section 4d of CC-BY-SA to the fullest extent permitted by applicable law.
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This book assists users and administrators in learning the processes and practices of securing
workstations and servers against local and remote intrusion, exploitationand malicious activity.
Focused on Red Hat Enterprise Linux but detailing concepts and techniques valid for all Linux
systems, this guide details the planning and the tools involved in creating a secured computing
environment for the data center, workplace, and home.
With proper administrative knowledge, vigilance, and tools, systems running Linux can be both fully
functional and securedfrom most common intrusion and exploit methods.

Preface
vii
1. Document Conventions .................................................................................................. vii
1.1. Typographic Conventions .................................................................................... vii
1.2. Pull-quote Conventions....................................................................................... viii
1.3. Notes and Warnings ............................................................................................ ix
2. We Need Feedback! ....................................................................................................... ix
1. Security Overview
1
1.1. Introduction to Security................................................................................................. 1
1.1.1. What is Computer Security? ............................................................................... 1
1.1.2. SELinux ............................................................................................................ 3
1.1.3. Security Controls............................................................................................... 3
1.1.4. Conclusion ........................................................................................................ 4
1.2. Vulnerability Assessment .............................................................................................. 5
1.2.1. Thinking Like the Enemy ................................................................................... 5
1.2.2. Defining...