X Windows Security: How to Protect your Display

The X Windows is as described in the X man pages a 'portable network-transparent window system'. X Windows is such a powerful and flexible interface that the user does not have to be in front of the machine to interact with it. Instead the user can be remotely located working in a transparent way. X Windows uses a client/server model where the client-server communications are done following the X protocol. X Windows as the time of this writing is in its version eleven release 6 (X11R6). The X consortium is in charge of maintaining the X Windows System and provides it free of charge and open source. X Windows is the standard protocol among UNIX-like systems but it is so popular that there are also implementations for personal computers and Macintosh that allow X emulation. There is even dedicate hardware equipment that only knows how to talk the X protocol language the so called X-terminals. This paper analyzes the threads and describe the security involved in the X Window Systems. It takes a practical overview of the X Windows security to emphasize the risks and indicate the measurements that must be taken.