The mldinput function in sys/netinet6/mld6.c in the kernel in NetBSD 4.0, FreeBSD, and KAME, when INET6 is enabled, allows remote attackers to cause a denial of service (divide-by-zero error and panic) via a malformed ICMPv6 Multicast Listener Discovery (MLD) query with a certain Maximum Response Delay value.
The ipcomp6input function in sys/netinet6/ipcompinput.c in the KAME project before 20071201 does not properly check the return value of the mpulldown function, which allows remote attackers to cause a denial of service (system crash) via an IPv6 packet with an IPComp header.