/usr/lib/x86_64-linux-gnu/libCnoidBody.so is in libcnoid-dev 1.5.0+dfsg-0.1build3.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libCnoidBody.so.1.5
/usr/lib/x86_64-linux-gnu/libCnoidBody.so.1.5