/usr/lib/x86_64-linux-gnu/libxcb-screensaver.so.0 is in libxcb-screensaver0 1.11.1-1ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/x86_64-linux-gnu/libxcb-screensaver.so.0.0.0
/usr/lib/x86_64-linux-gnu/libxcb-screensaver.so.0.0.0