Heap-based buffer overflow in the AppleTalk networking stack in XNU 1228.3.13 and earlier on Apple Mac OS X 10.5.6 and earlier allows remote attackers to cause a denial of service (system crash) via a ZIP NOTIFY (aka ZIPOP_NOTIFY) packet that overwrites a certain ifPort structure member. (CVSS:10.0) (Last Update:2009-04-18)