/usr/lib/x86_64-linux-gnu/libkadm5clnt.so.7 is in libkadm5clnt7-heimdal 1.7~git20150920+dfsg-4ubuntu1.16.04.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libkadm5clnt.so.7.0.1