/usr/lib/x86_64-linux-gnu/libvorbis.so is in libvorbis-dev 1.3.5-4+deb9u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libvorbis.so.0.4.8
/usr/lib/x86_64-linux-gnu/libvorbis.so.0.4.8