jackson-databind: incomplete fix for CVE-2017-7525 permits unsafe serialization via c3p0 libraries

A flaw was discovered in FasterXML jackson-databind, where it would permit polymorphic deserialization of malicious objects using the c3p0 gadget when used in conjunction with polymorphic type handling methods such as enableDefaultTyping or when @JsonTypeInfo is using Id.CLASS or Id.MINIMALCLASS ...