This is the 6th security advisory of FreeBSD for the year 2004. The problem is with FreeBSD’s IPv6 implementation, which in turn does not affect our systems at all, because all servers I maintain has disabled IPv6 completely, since there’s no IPv6 devices available at Beijing University of Technology’s public network.

p4 has corrected a setsockopt(2) IPv6 sockets input validation error. Patch againast this issue can be obtained from here. Personally, I’d suggest you to use 5-CURRENT instead of 5.2.1-RELEASE branch, as it has significant performance and stablity improvements.