/usr/lib/x86_64-linux-gnu/libexempi.so is in libexempi-dev 2.2.1-1ubuntu1.1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libexempi.so.3.2.3
/usr/lib/x86_64-linux-gnu/libexempi.so.3.2.3