find_xdg_file (int xdg_type, const char* filename) {
    /* xdg_type = 0 => config
       xdg_type = 1 => data
       xdg_type = 2 => cache*/

    gchar* xdgv = get_xdg_var (XDG[xdg_type]);
    gchar* temporary_file = g_strconcat (xdgv, filename, NULL);
    g_free (xdgv);

    gchar* temporary_string;
    char*  saveptr;
    char*  buf;

    if (! file_exists (temporary_file) && xdg_type != 2) {
        buf = get_xdg_var (XDG[3 + xdg_type]);
        temporary_string = (char *) strtok_r (buf, ":", &saveptr);
        g_free(buf);

        while ((temporary_string = (char * ) strtok_r (NULL, ":", &saveptr)) && ! file_exists (temporary_file)) {
            g_free (temporary_file);
            temporary_file = g_strconcat (temporary_string, filename, NULL);
        }
    }


    if (file_exists (temporary_file)) {
        return temporary_file;
    } else {
        g_free(temporary_file);
        return NULL;
    }
}

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