local unsigned long time2dos(time_t t)
{
    struct tm *tm;
    unsigned long dos;

    if (t == 0)
        t = time(NULL);
    tm = localtime(&t);
    if (tm->tm_year < 80 || tm->tm_year > 207)
        return 0;
    dos = (tm->tm_year - 80) << 25;
    dos += (tm->tm_mon + 1) << 21;
    dos += tm->tm_mday << 16;
    dos += tm->tm_hour << 11;
    dos += tm->tm_min << 5;
    dos += (tm->tm_sec + 1) >> 1;   /* round to double-seconds */
    return dos;
}

The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory.