Linux System Security: The Administrator's Guide to Open Source Security Tools, Second Edition - Hardcover

Mann, Scott; Mitchell, Ellen L.; Krell, Mitchell; Krell, Mitch

Hardcover

ISBN 10: 0130470112 ISBN 13: 9780130470119

Publisher: Prentice Hall Ptr, 2002

Synopsis

Lock down your Linux system now with Linux System Security, Second Edition - the up-to-the-minute, hands-on guide to open source security. It covers firewalls, intrusion detection, authentication, secure Web services, VPNs, and much more. This new edition includes coverage of Bastille and OpenSSH, plus key tools like sudo, portmap, xinetd, tiger, tripwire, ipchains, pam, and crack. Learn how to prepare systems for production environments; prevent common attacks; even protect mixed Linux/UNIX environments.

About this title

About the Author

SCOTT MANN is a Linux software engineer at LeftHand Networks in Colorado. He has previously specialized in Linux and UNIX systems for both SGI and Sun Microsystems. His previous Prentice Hall PTR books include Linux TCP/IP Network Administration.

ELLEN L. MITCHELL is a security analyst at Texas A&M University, where she is responsible for campus network security, development, and administration. She currently maintains the Tiger UNIX security package.

MITCHELL KRELL, Ph.D., is a former university professor turned consultant. He currently travels around the country teaching classes and consulting for various government agencies on a variety of topics including Linux, IRIX, system administration, networking, web development, and computer security.

From the Back Cover

Lock down your Linux system NOW!

• Up-to-the-minute security techniques for your entire Linux environment!
• NEW! In-depth coverage of Bastille, the breakthrough Linux lockdown tool!
• NEW! Intrusion detection with network sniffers and port scanners
• NEW! Complete coverage of the OpenSSH encryption suite
• Firewalls, email, Web services, filesystems, applications, and more
• Completely updated for RedHat 7.2

Now there's an up-to-the-minute, hands-on guide to using open source tools to protect any Linux system! Completely updated for the newest tools and distributions, Linux System Security, Second Edition covers virtually every facet of Linux security, from firewalls and intrusion detection to authentication and secure Web services. You'll master over a dozen crucial open source security tools, including sudo, portmap, xinetd, tiger, tripwire, ipchains, pam, crack, and more. Along the way, three long-time Linux sysadmins will show you the "gotchas," rules of thumb, and undocumented tricks it would take you years to learn on your own!

• Preparing Linux systems for a production environment
• Using Bastille to lock down Linux systems without unnecessarily compromising their functionality
• Combatting Trojan horses, backdoors, password cracking, buffer overflows, spoofing, DoS, and more
• OpenSSH: eliminating eavesdropping, connection hijacking, and other network-level attacks
• Detecting intrusions with network sniffers and port scanners
• Firewalls, email, Web services, filesystems, applications, and much more
• Protecting mixed Linux/UNIX(r) environments
• Includes a concise introduction to security policies

Want the benefits of Linux without the security risks? Get Linux System Security, Second Edition!

Prentice Hall Series on Computer Networking and Distributed Systems, Radia Perlman, Series Advisor

Excerpt. © Reprinted by permission. All rights reserved.

Preface

This book exists because we need it! In many ways, we (well, Scott, anyway) wish someone else had written it so that we could have just read it. We have found that it is much easier to read than it is to write (unlike disk drives, however, it takes orders of magnitude longer to write than to read)!

This book provides an introduction to installing, configuring, and maintaining Linux systems from a security perspective. In fact, it is really an administrator's guide to implementing security and security tools on Linux (although much of what is discussed can easily apply to other UNIX variants). It isn't a definitive book about security (there aren't any), but we think it provides a reasonable starting point for preparing and maintaining secure systems. If you follow the procedures outlined in this book, you will certainly reduce your overall level of vulnerability, and you will have an early warning system that may be able to prevent the most serious of system and network breaches.

We really tried to avoid discussing topics that are covered well elsewhere. Subjects such as cryptography, security policies, Transmission Control Protocol/Internet Protocol (TCP/IP) networking, firewalls, and so on, are well documented in other sources. We've noted resources for these topics at the end of each appropriate chapter and in Appendix A. We've also tried to provide similar resources for the many topics we did not have time to cover (publishers are so deadline intensive).

This book will not teach you how to break into systems, although some obvious tricks are described to heighten your awareness. Neither will this document describe the process of system and code auditing for vulnerability assessment-that task is left to people far more industrious than we are. Simply, this book will provide a framework-a foundation if you will-that will allow you to learn more and, hopefully, be as dynamic as the field of computer security itself.About This Book

The intent of this book is to give you a process to follow (with whatever modifications you feel are appropriate) to better secure your computing environment. We also tried to write in such a way that each chapter could stand on its own. For those of you who are unfamiliar with implementing secure computing environments, you may well benefit from reading this book in its entirety and then using it as a reference. If you are really new to the subject of security, read Practical UNIX and Internet Security or something similar first. Then read this book.

We have included instructions for compiling most of the utilities covered in this book. The reason behind such madness (mad, because those instructions will be out of date very quickly) is that, while there are resources that generically describe the procedure of building software, there are few that provide real-world examples. It has been our experience that very few new or junior system and network administrators have the experience necessary to fetch a publicly available tool, modify it appropriately, and successfully compile it. It is for those readers in particular that we have included these instructions. For those of you who don't need those instructions, just skip over them.

The first four chapters are overviews. We begin in Chapter 1 with a survey of vulnerabilities. Chapter 2 introduces the critical topic of security policies. Chapter 3 covers a wide range of topics from cryptography to networking to give us a framework for what follows. Chapter 4 provides a survey of user accounts, file permissions, and filesystem options as they relate to security.

Chapters 7 and 8 cover the topics of system accounting and system logging, respectively. A book about system security would not be complete without a discussion of these topics, which are very important in securing a system. Chapters 5, 6, and 9-17 are the heart of the book, providing a detailed look at utilizing the security capabilities of Linux and implementing publicly available tools to augment Linux security. Please be sure to learn about and utilize tiger (Chapter 13) and Tripwire (Chapter 14) before going live with any of the tools discussed elsewhere in the book. These two utilities will give you a high confidence level regarding the state of security of your systems, if used properly.

Chapter 18 shows how to implement all that is covered in the book. If you are in a hurry, you may want to read through this chapter early on in your study of this topic to get a sense of what needs to be done to provide a secure environment.

We sincerely hope you find this book as useful as we do!Errata or, More Simply, Bugs

There will be those! While we tested everything presented in this book for accuracy on RedHat 5.2 and almost everything on Red Hat 6.0, there are undoubtedly mistakes in this text. If you find any, please email them or any other comments you might have to us atlinux_upat@thekeyboard.com

We probably won't always answer, but we will post updates and corrections to a site that we'll link off of this book's catalog page on the publisher's website:phptr/ptrbooks/ptr_0130158070.html

Please check the site once in a while for new information.

Edition details

• Publisher: Prentice Hall Ptr
• Publication date: 2002
• Language: English
• ISBN 10: 0130470112
• ISBN 13: 9780130470119
• Binding: Hardcover
• Number of pages: 857