/usr/lib/debian-installer/images/7.0/i386/text/pxelinux.0 is in debian-installer-7.0-netboot-i386 20130613+deb7u3.b2.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/lib/debian-installer/images/7.0/i386/text/debian-installer/i386/pxelinux.0