The Shellshock vulnerability affects the way in which the computer executes the commands that are entered at the terminal. This can result in a malicious hacker being able to take control of the machine and steal information. Shellshock can be exploited on various operating systems, including Windows, Mac OS X, and Linux. The attack vector is the user who is logged in to a remote machine and has shell access.

The Shellshock vulnerability is a security issue that affects all the *nix-based operating systems and all the software that uses the shell as an interface. It allows an attacker to execute arbitrary commands on the machine and to obtain sensitive information.