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Practical Linux Security Cookbook

You're reading from   Practical Linux Security Cookbook Secure your Linux machines and keep them secured with the help of exciting recipes

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Product type Paperback
Published in Apr 2016
Publisher Packt
ISBN-13 9781785286421
Length 276 pages
Edition 1st Edition
Tools
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Authors (2):
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Michael A Lindner Michael A Lindner
Author Profile Icon Michael A Lindner
Michael A Lindner
Tajinder Kalsi Tajinder Kalsi
Author Profile Icon Tajinder Kalsi
Tajinder Kalsi
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Toc

Table of Contents (12) Chapters Close

Preface 1. Linux Security Problems FREE CHAPTER 2. Configuring a Secure and Optimized Kernel 3. Local Filesystem Security 4. Local Authentication in Linux 5. Remote Authentication 6. Network Security 7. Security Tools 8. Linux Security Distros 9. Patching a Bash Vulnerability 10. Security Monitoring and Logging Index

Disabling or enabling SSH root login

The Linux systems have a root account by default, which is enabled by default. If unauthorized users get SSH root access to the system, it is not a good idea because this will give an attacker complete access to the system.

We can disable or enable the root login for SSH as per our requirements to prevent the chances of an attacker getting access to the system.

Getting ready

We need two Linux systems to be used as a server and client. On the server system, install the package openssh-server, as shown in the preceding recipe.

How to do it…

First, we will see how to disable SSH root login, and then we will also see how to enable it again:

  1. Firstly, open the main configuration file of SSH, /etc/ssh/sshd_config, in any editor.
    sudo nano /etc/ssh/sshd_config
    
  2. Now look for the line that reads as follows:
    PermitRootLogin yes
    
  3. Change the value from yes to no. Then, save and close the file:
    PermitRootLogin no
    
    • The output obtained will be as follows:
    How to do it…
  4. Once done, restart...
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