clone() Method Without super.clone()
Weakness ID: 580 (Weakness Variant)Status: Draft
+ Description

Description Summary

The software contains a clone() method that fails to call super.clone() to obtain the new object.

Extended Description

All implementations of clone() should obtain the new object by calling super.clone(). If a class fails to follow this convention, a subclass's clone() method will return an object of the wrong type.

+ Time of Introduction
  • Implementation
+ Applicable Platforms

Languages

Java

+ Demonstrative Examples

Example 1

The following two classes demonstrate a bug introduced by failing to call super.clone(). Because of the way Kibitzer implements clone(), FancyKibitzer's clone method will return an object of type Kibitzer instead of FancyKibitzer.

(Bad Code)
Example Language: Java 
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();
...
}
}
+ Potential Mitigations

Phase: Implementation

Call super.clone() within your clone() method, when obtaining a new object.

Phase: Implementation

In some cases, you can eliminate the clone method altogether and use copy constructors.

+ Relationships
NatureTypeIDNameView(s) this relationship pertains toView(s)
ChildOfWeakness ClassWeakness Class485Insufficient Encapsulation
Development Concepts (primary)699
Research Concepts (primary)1000
ChildOfWeakness ClassWeakness Class573Failure to Follow Specification
Development Concepts699
Research Concepts1000
+ Content History
Modifications
Modification DateModifierOrganizationSource
2008-07-01Eric DalciCigitalExternal
updated Potential Mitigations, Time of Introduction
2008-09-08CWE Content TeamMITREInternal
updated Relationships, Other Notes
2009-07-27CWE Content TeamMITREInternal
updated Description, Other Notes, Potential Mitigations
Previous Entry Names
Change DatePrevious Entry Name
2008-04-11Erroneous Clone Method
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