/usr/share/ is in fusionforge-plugin-authcas 6.0.3+20151023-1ubuntu1.
This file is owned by root:root, with mode 0o755.
..
/usr/share/fusionforge/post-install.d/
/usr/share/fusionforge/cronjobs/
/usr/share/fusionforge/plugins/
/usr/share/fusionforge/plugins/authcas/
/usr/share/fusionforge/plugins/authcas/etc/
/usr/share/fusionforge/
/usr/share/doc/
/usr/share/doc/fusionforge-plugin-authcas/
/usr/share/doc/fusionforge-plugin-authcas/copyright
/usr/share/doc/fusionforge-plugin-authcas/README
/usr/share/fusionforge/plugins/authcas/etc/authcas.ini
/usr/share/fusionforge/plugins/authcas/common/
/usr/share/fusionforge/plugins/authcas/common/AuthCASPlugin.class.php
/usr/share/fusionforge/plugins/authcas/common/authcas-init.php
/usr/share/fusionforge/plugins/authcas/www/
/usr/share/fusionforge/plugins/authcas/www/post-login.php
/usr/share/fusionforge/plugins/authcas/README
/usr/share/doc/fusionforge-plugin-authcas/changelog.Debian.gz