/usr/share/doc/xscreensaver/changelog.Debian.gz is in xscreensaver 5.15-2ubuntu1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/xscreensaver/../xscreensaver-data/changelog.Debian.gz
/usr/share/doc/xscreensaver/../xscreensaver-data/changelog.Debian.gz