Non-final 'clone()' in secure context

Reports clone() methods without the final modifier.

Since clone() can be used to instantiate objects without using a constructor, allowing the clone() method to be overridden may result in corrupted objects, and even in security exploits. This may be prevented by making the clone() method or the enclosing class itself final.

Example:

class Main implements Cloneable {
  @Override
  protected Object clone() throws CloneNotSupportedException {
    return super.clone();
  }
}