isakmpd in OpenBSD 3.4 and earlier allows remote attackers to cause a denial of service (crash) via an ISAKMP packet with a delete payload containing a large number of SPIs, which triggers an out-of-bounds read error, as demonstrated by the Striker ISAKMP Protocol Test Suite.
https://exchange.xforce.ibmcloud.com/vulnerabilities/15630
http://www.openbsd.org/errata.html