void AddActionCallback(const ActionCallback& callback) {
  DCHECK(g_task_runner.Get());
  DCHECK(g_task_runner.Get()->BelongsToCurrentThread());
  g_callbacks.Get().push_back(callback);
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.