/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/ is in debian-edu-config 1.702.
This file is owned by root:root, with mode 0o755.
..
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/000-arch-detection
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/000-default-dist
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/002-default-apt-keyring
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/010-set-resolver
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/011-http-nopipeline
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/015-edu-apt-source
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/020-rootpath
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/025-bootprompt-opts
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/032-edu-pkgs
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/035-default-lts-conf
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/045-remove-udev-net-rules
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/050-nbdquery
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/095-umount-error
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/098-etckeeper
/usr/share/ltsp/plugins/ltsp-build-client/Debian-custom/099-mount-cdrom