/usr/share/xscreensaver/ is in rss-glx 0.9.1-6ubuntu4.
This file is owned by root:root, with mode 0o755.
..
/usr/share/xscreensaver/config/
/usr/share/xscreensaver/config/biof.xml
/usr/share/xscreensaver/config/busyspheres.xml
/usr/share/xscreensaver/config/colorfire.xml
/usr/share/xscreensaver/config/cyclone.xml
/usr/share/xscreensaver/config/drempels.xml
/usr/share/xscreensaver/config/euphoria.xml
/usr/share/xscreensaver/config/feedback.xml
/usr/share/xscreensaver/config/fieldlines.xml
/usr/share/xscreensaver/config/flocks.xml
/usr/share/xscreensaver/config/flux.xml
/usr/share/xscreensaver/config/helios.xml
/usr/share/xscreensaver/config/hufo_smoke.xml
/usr/share/xscreensaver/config/hufo_tunnel.xml
/usr/share/xscreensaver/config/hyperspace.xml
/usr/share/xscreensaver/config/lattice.xml
/usr/share/xscreensaver/config/lorenz.xml
/usr/share/xscreensaver/config/matrixview.xml
/usr/share/xscreensaver/config/pixelcity.xml
/usr/share/xscreensaver/config/plasma.xml
/usr/share/xscreensaver/config/skyrocket.xml
/usr/share/xscreensaver/config/solarwinds.xml
/usr/share/xscreensaver/config/spirographx.xml
/usr/share/xscreensaver/config/sundancer2.xml