/usr/lib/x86_64-linux-gnu/libpoppler-cpp.so.0 is in libpoppler-cpp0v5 0.48.0-2+deb9u2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libpoppler-cpp.so.0.3.0
/usr/lib/x86_64-linux-gnu/libpoppler-cpp.so.0.3.0