/usr/lib/x86_64-linux-gnu/libruby-2.3.so.2.3 is in libruby2.3 2.3.3-1+deb9u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libruby-2.3.so.2.3.0
/usr/lib/x86_64-linux-gnu/libruby-2.3.so.2.3.0