static void vnc_display_close(DisplayState *ds)
{
    VncDisplay *vs = vnc_display;

    if (!vs)
        return;
    g_free(vs->display);
    vs->display = NULL;
    if (vs->lsock != -1) {
        qemu_set_fd_handler2(vs->lsock, NULL, NULL, NULL, NULL);
        close(vs->lsock);
        vs->lsock = -1;
    }
#ifdef CONFIG_VNC_WS
    g_free(vs->ws_display);
    vs->ws_display = NULL;
    if (vs->lwebsock != -1) {
        qemu_set_fd_handler2(vs->lwebsock, NULL, NULL, NULL, NULL);
        close(vs->lwebsock);
        vs->lwebsock = -1;
    }
#endif /* CONFIG_VNC_WS */
    vs->auth = VNC_AUTH_INVALID;
#ifdef CONFIG_VNC_TLS
    vs->subauth = VNC_AUTH_INVALID;
    vs->tls.x509verify = 0;
#endif
}

This category addresses vulnerabilities caused by flawed access control mechanisms, where incorrect permission settings allow unauthorized users to access restricted resources.