This affects the FreeBSD version because under FreeBSD the program must be installed setgid kmem or setuid root in order to access system load information through the memory devices. The Linux version should not be vulnerable because it reads information through procfs which requires no special privileges. Monitoring 2 devices for activity. Give up privs. The exploit and patch were tested with wmmon 1.0.b2 installed using the ports tree.
Standard disclaimers apply.
I first emailed the FreeBSD wmmon port maintainer about this back in February. At that time the program was installed setuid root, giving easy access to user root instead of just group kmem. I forgot about it until a few weeks ago when I checked the port again. The problem still exists, it has just been reduced from a root exploit to kmem.