/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/ is in libcdk-perl 20150928-1+b2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Alphalist.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Buttonbox.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Calendar.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Debug.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Diag.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Dialog.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Entry.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Fselect.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Graph.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Histogram.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Itemlist.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Label.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Marquee.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Matrix.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Mentry.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Menu.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Radio.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Scale.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Scroll.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Selection.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Slider.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Swindow.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Template.pm
/usr/lib/x86_64-linux-gnu/perl5/5.24/Cdk/Viewer.pm