static CURLcode smtp_perform_helo(struct connectdata *conn)
{
  CURLcode result = CURLE_OK;
  struct smtp_conn *smtpc = &conn->proto.smtpc;

  smtpc->sasl.authused = SASL_AUTH_NONE; /* No authentication mechanism used
                                            in smtp connections */

  /* Send the HELO command */
  result = Curl_pp_sendf(&smtpc->pp, "HELO %s", smtpc->domain);

  if(!result)
    state(conn, SMTP_HELO);

  return result;
}

The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.