CVE 2009-1957
charon/sa/ike_sa.c in the charon daemon in strongSWAN before 4.3.1 allows remote attackers to cause a denial of service (NULL pointer dereference and crash) via an invalid IKE_SA_INIT request that triggers "an incomplete state," followed by a CREATE_CHILD_SA request.
See the 
CVE page on Mitre.org
for more details.
