$ sudo apt-get update
$ sudo apt-get install libgsasl7 

libgsasl7 is installed in your system.

Make ensure the libgsasl7 package were installed using the commands given below,

$ sudo dpkg-query -l | grep libgsasl7 *

You will get with libgsasl7 package name, version, architecture and description in a table

libgsasl7 package basic information: