static void reds_on_main_agent_monitors_config(
        MainChannelClient *mcc, void *message, size_t size)
{
    VDAgentMessage *msg_header;
    VDAgentMonitorsConfig *monitors_config;
    RedsClientMonitorsConfig *cmc = &reds->client_monitors_config;

    cmc->buffer_size += size;
    cmc->buffer = realloc(cmc->buffer, cmc->buffer_size);
    spice_assert(cmc->buffer);
    cmc->mcc = mcc;
    memcpy(cmc->buffer + cmc->buffer_pos, message, size);
    cmc->buffer_pos += size;
    msg_header = (VDAgentMessage *)cmc->buffer;
    if (sizeof(VDAgentMessage) > cmc->buffer_size ||
            msg_header->size > cmc->buffer_size - sizeof(VDAgentMessage)) {
        spice_debug("not enough data yet. %d\n", cmc->buffer_size);
        return;
    }
    monitors_config = (VDAgentMonitorsConfig *)(cmc->buffer + sizeof(*msg_header));
    spice_debug("%s: %d\n", __func__, monitors_config->num_of_monitors);
    red_dispatcher_client_monitors_config(monitors_config);
    reds_client_monitors_config_cleanup();
}

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.