/usr/share/nagios3/htdocs/images/dot.png is in nagiosgrapher 1.7.1-4.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/nagios3/htdocs/images/../../../nagiosgrapher/htdocs/images/dot.png
/usr/share/nagios3/htdocs/images/../../../nagiosgrapher/htdocs/images/dot.png