Penetration Testing on X11 Server
X is an architecture-independent system for remote graphical user interfaces and input device capabilities. Each person using a networked terminal has the ability to interact with the display with any type of user input device.
Source: Wikipedia
In most of the cases the X’s Server’s access control is disabled. But if enabled, it allows anyone to connect to the server. This Vulnerability is called X11 Server Unauthenticated Access Open. You can get more information form here.
For a proper demonstration, we will have to create up a Lab with this Vulnerability.
Lab Setup
We will use Ubuntu 14.04 system for this Vulnerable Lab setup. After the basic installation of the Ubuntu Server, we will focus on locating the “lightdm.conf” file. The Location of this file is: /etc/lightdm/lightdm.conf. But if you can’t seem to find this at that location, you can get it for yourself from here.
To edit the file, we will use gedit.
gedit /etc/lightdm/lightdm.conf
FUll Article Read Here