The kernel in Apple Mac OS X before 10.8.5 allows remote attackers to cause a denial of service (panic) via crafted IGMP packets that leverage incorrect, extraneous code in the IGMP parser.
Apple Security Advisory 2013-09-12-1 - OS X Mountain Lion v10.8.5 and Security Update 2013-004 is now available and addresses Apache issues, BIND issues, ClamAV issues, and more.