/usr/lib/x86_64-linux-gnu/libevent.so is in libevent-dev 2.0.21-stable-2+deb8u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libevent-2.0.so.5.1.9
/usr/lib/x86_64-linux-gnu/libevent-2.0.so.5.1.9