The SPL component in PHP before 5.4.30 and 5.5.x before 5.5.14 incorrectly anticipates that certain data structures will have the array data type after unserialization, which allows remote attackers to execute arbitrary code via a crafted string that triggers use of a Hashtable destructor, related to "type confusion" issues in (1) ArrayObject and (2) SPLObjectStorage.
http://git.php.net/?p=php-src.git%3Ba=commit%3Bh=88223c5245e9b470e1e6362bfd96829562ffe6ab
http://lists.opensuse.org/opensuse-updates/2014-09/msg00046.html
http://marc.info/?l=bugtraq&m=141017844705317&w=2
http://rhn.redhat.com/errata/RHSA-2014-1765.html
http://rhn.redhat.com/errata/RHSA-2014-1766.html
https://bugs.php.net/bug.php?id=67492
http://secunia.com/advisories/59794
http://secunia.com/advisories/59831
http://secunia.com/advisories/60998
http://support.apple.com/kb/HT6443
http://www-01.ibm.com/support/docview.wss?uid=swg21683486
http://www.debian.org/security/2014/dsa-2974
http://www.oracle.com/technetwork/topics/security/bulletinjan2015-2370101.html