/usr/lib/x86_64-linux-gnu/libCDApplet.so is in cairo-dock-plug-ins-dbus-interface-vala 3.4.1-0ubuntu7.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libCDApplet.so.1
/usr/lib/x86_64-linux-gnu/libCDApplet.so.1