Type confusion exists in _cancel_eval Ruby's TclTkIp class method. Attacker passing different type of object than String as retval argument can cause arbitrary code execution.<a href=http://cwe.mitre.org/data/definitions/843.html>CWE-843: Access of Resource Using Incompatible Type ('Type Confusion')</a>
http://web.nvd.nist.gov/view/vuln/detail?vulnId=CVE-2016-2337
