Network exploitation

In this section, we’ll dive into exploiting command injection vulnerabilities in web applications that fail to filter user input before passing data on to operating system commands.

Network service exploitation

In September 2014, a critical vulnerability was discovered in the Unix Bash shell. This vulnerability, assigned the CVE-2014-6271 identifier and nicknamed Shellshock, sent shockwaves through the information security community due to its severity and widespread impact. Let’s dive into the technical details of this vulnerability and explore how it can be exploited.

The Shellshock vulnerability stems from a flaw in how Bash processes environment variables. Specifically, it allows an attacker to execute arbitrary commands by manipulating environment variables in a crafted manner.

In Bash, environment variables can be defined in the following format:

VAR=value

However, Bash also supports a feature called function exporting, which...