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.<a href=http://cwe.mitre.org/data/definitions/843.html>Access of Resource Using Incompatible Type ('Type Confusion')</a>
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2015-4603
