/usr/lib/x86_64-linux-gnu/libCgl.so is in coinor-libcgl-dev 0.58.4-2ubuntu2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libCgl.so.1.8.4
/usr/lib/x86_64-linux-gnu/libCgl.so.1.8.4