The (1) IPv6 and (2) ATM ioctl request handlers in the kernel in FreeBSD 8.3 through 9.2-STABLE do not validate SIOCSIFADDR, SIOCSIFBRDADDR, SIOCSIFDSTADDR, and SIOCSIFNETMASK requests, which allows local users to perform link-layer actions, cause a denial of service (panic), or possibly gain privileges via a crafted application.