/usr/share/cdbs/1/class/ is in cdbs 0.4.156ubuntu4.
This file is owned by root:root, with mode 0o755.
..
/usr/share/cdbs/1/class/ant-vars.mk
/usr/share/cdbs/1/class/ant.mk
/usr/share/cdbs/1/class/autotools-files.mk
/usr/share/cdbs/1/class/autotools-vars.mk
/usr/share/cdbs/1/class/autotools.mk
/usr/share/cdbs/1/class/cmake.mk
/usr/share/cdbs/1/class/gnome.mk
/usr/share/cdbs/1/class/langcore.mk
/usr/share/cdbs/1/class/makefile-vars.mk
/usr/share/cdbs/1/class/makefile.mk
/usr/share/cdbs/1/class/pd.mk
/usr/share/cdbs/1/class/perl-build-vars.mk
/usr/share/cdbs/1/class/perl-build.mk
/usr/share/cdbs/1/class/perl-makemaker-vars.mk
/usr/share/cdbs/1/class/perl-makemaker.mk
/usr/share/cdbs/1/class/perl-vars.mk
/usr/share/cdbs/1/class/perlmodule-vars.mk
/usr/share/cdbs/1/class/perlmodule.mk
/usr/share/cdbs/1/class/python-autotools.mk
/usr/share/cdbs/1/class/python-distutils.mk
/usr/share/cdbs/1/class/python-module.mk
/usr/share/cdbs/1/class/python-sugar.mk
/usr/share/cdbs/1/class/python-vars.mk
/usr/share/cdbs/1/class/qmake.mk
/usr/share/cdbs/1/class/scons-vars.mk
/usr/share/cdbs/1/class/scons.mk
/usr/share/cdbs/1/class/waf.mk