$ sudo apt-get update
$ sudo apt-get install libcfg6 

libcfg6 is installed in your system.

Make ensure the libcfg6 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libcfg6 *

You will get with libcfg6 package name, version, architecture and description in a table

libcfg6 package basic information: