FreeBSD 6.3, 6.4, 7.1, and 7.2 does not enforce permissions on the SIOCSIFINFO_IN6 IOCTL, which allows local users to modify or disable IPv6 network interfaces, as demonstrated by modifying the MTU.
Exploitability
AV:LAC:LAu:NImpact
C:NI:PA:P3.6/AV:L/AC:L/Au:N/C:N/I:P/A:P