Memory leak in the timezone functionality in PHP before 5.3.9 allows remote attackers to cause a denial of service (memory consumption) by triggering many strtotime function calls, which are not properly handled by the php_date_parse_tzfile cache.
http://lists.opensuse.org/opensuse-security-announce/2012-03/msg00013.html
http://lists.opensuse.org/opensuse-security-announce/2012-03/msg00016.html
https://bugs.php.net/bug.php?id=53502
https://bugzilla.redhat.com/show_bug.cgi?id=783609