static CURLcode smtp_state_helo_resp(struct connectdata *conn, int smtpcode,
                                     smtpstate instate)
{
  CURLcode result = CURLE_OK;
  struct Curl_easy *data = conn->data;

  (void)instate; /* no use for this yet */

  if(smtpcode/100 != 2) {
    failf(data, "Remote access denied: %d", smtpcode);
    result = CURLE_REMOTE_ACCESS_DENIED;
  }
  else
    /* End of connect phase */
    state(conn, SMTP_STOP);

  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.