How To Patch and Protect Linux Server Against the Glibc GHOST Vulnerability # CVE-2015-0235

A very serious security problem has been found and patched in the GNU C Library called Glibc. It was announced on 27th January 2015. How can I fix GHOST vulnerability and protect my Linux server against the attack?

How do I verify that my server has been fixed against the Glibc GHOST vulnerability?