isakmpd in OpenBSD 3.4 and earlier allows remote attackers to cause a denial of service via an ISAKMP packet with a malformed Cert Request payload, which causes an integer underflow that is used in a malloc operation that is not properly handled, as demonstrated by the Striker ISAKMP Protocol Test Suite.
Improper Restriction of Operations within the Bounds of a Memory Buffer The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary.