The exception::getTraceAsString function in Zend/zend_exceptions.c in PHP before 5.4.40, 5.5.x before 5.5.24, and 5.6.x before 5.6.8 allows remote attackers to execute arbitrary code via an unexpected data type, related to a “type confusion” issue.
php.net/ChangeLog-5.php
rhn.redhat.com/errata/RHSA-2015-1135.html
rhn.redhat.com/errata/RHSA-2015-1186.html
rhn.redhat.com/errata/RHSA-2015-1187.html
rhn.redhat.com/errata/RHSA-2015-1218.html
www.openwall.com/lists/oss-security/2015/06/16/12
www.oracle.com/technetwork/topics/security/linuxbulletinjan2016-2867209.html
www.securityfocus.com/bid/75252
www.securitytracker.com/id/1032709
bugs.php.net/bug.php?id=69152