void RenderFrameHostImpl::OnEnterFullscreen(
    const blink::WebFullscreenOptions& options) {
  std::set<SiteInstance*> notified_instances;
  notified_instances.insert(GetSiteInstance());
  for (FrameTreeNode* node = frame_tree_node_; node->parent();
       node = node->parent()) {
    SiteInstance* parent_site_instance =
        node->parent()->current_frame_host()->GetSiteInstance();
    if (ContainsKey(notified_instances, parent_site_instance))
      continue;

    RenderFrameProxyHost* child_proxy =
        node->render_manager()->GetRenderFrameProxyHost(parent_site_instance);
    child_proxy->Send(
        new FrameMsg_WillEnterFullscreen(child_proxy->GetRoutingID()));
    notified_instances.insert(parent_site_instance);
  }

  delegate_->EnterFullscreenMode(GetLastCommittedURL().GetOrigin());

  render_view_host_->GetWidget()->SynchronizeVisualProperties();
}

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.