/usr/bin/pdfpun is in texlive-extra-utils 2014.20141024-1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/bin/../share/texlive/texmf-dist/scripts/pdfjam/pdfpun
/usr/bin/../share/texlive/texmf-dist/scripts/pdfjam/pdfpun