In CVE-2017-0358, author notes that
The issue is that /sbin/modprobe is not designed to run in a setuid context. As the manpage of modprobe explicitly points out
The MODPROBE_OPTIONS environment variable can also be used to pass arguments to modprobe.
modprobe is supposed to add/remove modules from kernel, which anyway requires root privileges.
So what does it mean to say that "modprobe is not designed to run in setuid context"?