local time_t dos2time(unsigned long dos)
{
    struct tm tm;

    if (dos == 0)
        return time(NULL);
    tm.tm_year = ((int)(dos >> 25) & 0x7f) + 80;
    tm.tm_mon  = ((int)(dos >> 21) & 0xf) - 1;
    tm.tm_mday = (int)(dos >> 16) & 0x1f;
    tm.tm_hour = (int)(dos >> 11) & 0x1f;
    tm.tm_min  = (int)(dos >> 5) & 0x3f;
    tm.tm_sec  = (int)(dos << 1) & 0x3e;
    tm.tm_isdst = -1;           /* figure out if DST or not */
    return mktime(&tm);
}

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.