Practical Linux Security Cookbook

Chapter 9. Patching a Bash Vulnerability

In this chapter, we will learn the following concepts:

• Understanding the bash vulnerability through Shellshock
• Shellshock's security issues
• The patch management system
• Applying patches on the Linux systems

Understanding the bash vulnerability through Shellshock

Shellshock, or Bashdoor, is a vulnerability that's used in most versions of the Linux and Unix operating systems. It was discovered on September 12, 2014, and it affects all the distributions of Linux using a bash shell. The Shellshock vulnerability makes it possible to execute commands remotely using environment variables.

Getting Ready

To understand Shellshock, we need a Linux system that uses a version of bash prior to 4.3, which is vulnerable to this ...