static void cmd_xmeid(const char *tag, const char *id)
{
    mboxevent_set_client_id(id);

    prot_printf(imapd_out, "%s OK %s\r\n", tag,
                error_message(IMAP_OK_COMPLETED));
}

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.