ipsec-tools -- remotely exploitable computational-complexity attack

Robert Foggia via NetBSD GNATS reports:

The ipsec-tools racoon daemon contains a remotely exploitable computational
complexity attack when parsing and storing isakmp fragments. The implementation
permits a remote attacker to exhaust computational resources on the remote endpoint
by repeatedly sending isakmp fragment packets in a particular order such that
the worst-case computational complexity is realized in the algorithm utilized
to determine if reassembly of the fragments can take place.