clone() Method Without super.clone()

The product contains a clone() method that does not call super.clone() to obtain the new object.


All implementations of clone() should obtain the new object by calling super.clone(). If a class does not follow this convention, a subclass's clone() method will return an object of the wrong type.


The following examples help to illustrate the nature of this weakness and describe methods or techniques which can be used to mitigate the risk.

Note that the examples here are by no means exhaustive and any given weakness may have many subtle varieties, each of which may require different detection methods or runtime controls.

Example One

The following two classes demonstrate a bug introduced by not calling super.clone(). Because of the way Kibitzer implements clone(), FancyKibitzer's clone method will return an object of type Kibitzer instead of FancyKibitzer.

public class Kibitzer {

  public Object clone() throws CloneNotSupportedException {

    Object returnMe = new Kibitzer();



public class FancyKibitzer extends Kibitzer{

  public Object clone() throws CloneNotSupportedException {

    Object returnMe = super.clone();



See Also

Comprehensive Categorization: Resource Lifecycle Management

Weaknesses in this category are related to resource lifecycle management.

SFP Secondary Cluster: Unexpected Entry Points

This category identifies Software Fault Patterns (SFPs) within the Unexpected Entry Points cluster.

Privilege Issues

Weaknesses in this category occur with improper handling, assignment, or management of privileges. A privilege is a property of an agent, such as a user. It lets the a...

Comprehensive CWE Dictionary

This view (slice) covers all the elements in CWE.

Weaknesses Introduced During Implementation

This view (slice) lists weaknesses that can be introduced during implementation.

Weaknesses in Software Written in Java

This view (slice) covers issues that are found in Java programs that are not common to all languages.

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