Public cloneable() Method Without Final ('Object Hijack')

Demonstrations

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

In this example, a public class "BankAccount" implements the cloneable() method which declares "Object clone(string accountnumber)":

public class BankAccount implements Cloneable{

  public Object clone(String accountnumber) throws
  CloneNotSupportedException
  {

    Object returnMe = new BankAccount(account number);
    ...


  }

}

Example Two

In the example below, a clone() method is defined without being declared final.

protected Object clone() throws CloneNotSupportedException {
  ...
}

See Also