I'm trying to track down this strange behavoir for years now. Always after installing software-updates the permissions of a lot of system-tools are broken as you can see below. I am reasonable ...
I fixed a permissin problem for nagios like discribed here. The command was: sudo dpkg-statoverride --update --add nagios www-data 2710 /var/lib/nagios3/rw sudo dpkg-statoverride --update --add ...