/usr/lib/x86_64-linux-gnu/libcfitsio.so.5 is in libcfitsio5 3.430-2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libcfitsio.so.5.3.43
/usr/lib/x86_64-linux-gnu/libcfitsio.so.5.3.43