DownloadItem* DownloadManagerImpl::CreateDownloadItem(
    const std::string& guid,
    uint32_t id,
    const base::FilePath& current_path,
    const base::FilePath& target_path,
    const std::vector<GURL>& url_chain,
    const GURL& referrer_url,
    const GURL& site_url,
    const GURL& tab_url,
    const GURL& tab_refererr_url,
    const std::string& mime_type,
    const std::string& original_mime_type,
    base::Time start_time,
    base::Time end_time,
    const std::string& etag,
    const std::string& last_modified,
    int64_t received_bytes,
    int64_t total_bytes,
    const std::string& hash,
    DownloadItem::DownloadState state,
    DownloadDangerType danger_type,
    DownloadInterruptReason interrupt_reason,
    bool opened,
    base::Time last_access_time,
    bool transient,
    const std::vector<DownloadItem::ReceivedSlice>& received_slices) {
  if (base::ContainsKey(downloads_, id)) {
    NOTREACHED();
    return nullptr;
  }
  DCHECK(!base::ContainsKey(downloads_by_guid_, guid));
  DownloadItemImpl* item = item_factory_->CreatePersistedItem(
      this, guid, id, current_path, target_path, url_chain, referrer_url,
      site_url, tab_url, tab_refererr_url, mime_type, original_mime_type,
      start_time, end_time, etag, last_modified, received_bytes, total_bytes,
      hash, state, danger_type, interrupt_reason, opened, last_access_time,
      transient, received_slices);
  downloads_[id] = base::WrapUnique(item);
  downloads_by_guid_[guid] = item;
  for (auto& observer : observers_)
    observer.OnDownloadCreated(this, item);
  DVLOG(20) << __func__ << "() download = " << item->DebugString(true);
  return item;
}

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.