FreeBSD Security Advisory FreeBSD-SA-05:06 – The default permissions on the /dev/iir device node allow unprivileged local users to open the device and execute ioctl calls. Unprivileged local users can send commands to the hardware supported by the iir(4) driver, allowing destruction of data and possible disclosure of data.
You can download this advisory from the following link: https://packetstormsecurity.com/files/download/39100/FreeBSD-SA-05-06.iir.txt
Source: https://packetstormsecurity.com/files/39100/FreeBSD-SA-05-06.iir.txt.html