static int mov_read_dref(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
    AVStream *st;
    MOVStreamContext *sc;
    int entries, i, j;

    if (c->fc->nb_streams < 1)
        return 0;
    st = c->fc->streams[c->fc->nb_streams-1];
    sc = st->priv_data;

    avio_rb32(pb); // version + flags
    entries = avio_rb32(pb);
     if (entries >= UINT_MAX / sizeof(*sc->drefs))
         return AVERROR_INVALIDDATA;
     av_free(sc->drefs);
     sc->drefs = av_mallocz(entries * sizeof(*sc->drefs));
     if (!sc->drefs)
         return AVERROR(ENOMEM);
    sc->drefs_count = entries;

    for (i = 0; i < sc->drefs_count; i++) {
        MOVDref *dref = &sc->drefs[i];
        uint32_t size = avio_rb32(pb);
        int64_t next = avio_tell(pb) + size - 4;

        if (size < 12)
            return AVERROR_INVALIDDATA;

        dref->type = avio_rl32(pb);
        avio_rb32(pb); // version + flags
        av_dlog(c->fc, "type %.4s size %d\n", (char*)&dref->type, size);

        if (dref->type == MKTAG('a','l','i','s') && size > 150) {
            /* macintosh alias record */
            uint16_t volume_len, len;
            int16_t type;

            avio_skip(pb, 10);

            volume_len = avio_r8(pb);
            volume_len = FFMIN(volume_len, 27);
            avio_read(pb, dref->volume, 27);
            dref->volume[volume_len] = 0;
            av_log(c->fc, AV_LOG_DEBUG, "volume %s, len %d\n", dref->volume, volume_len);

            avio_skip(pb, 12);

            len = avio_r8(pb);
            len = FFMIN(len, 63);
            avio_read(pb, dref->filename, 63);
            dref->filename[len] = 0;
            av_log(c->fc, AV_LOG_DEBUG, "filename %s, len %d\n", dref->filename, len);

            avio_skip(pb, 16);

            /* read next level up_from_alias/down_to_target */
            dref->nlvl_from = avio_rb16(pb);
            dref->nlvl_to   = avio_rb16(pb);
            av_log(c->fc, AV_LOG_DEBUG, "nlvl from %d, nlvl to %d\n",
                   dref->nlvl_from, dref->nlvl_to);

            avio_skip(pb, 16);

            for (type = 0; type != -1 && avio_tell(pb) < next; ) {
                if(url_feof(pb))
                    return AVERROR_EOF;
                type = avio_rb16(pb);
                len = avio_rb16(pb);
                av_log(c->fc, AV_LOG_DEBUG, "type %d, len %d\n", type, len);
                if (len&1)
                    len += 1;
                if (type == 2) { // absolute path
                    av_free(dref->path);
                    dref->path = av_mallocz(len+1);
                    if (!dref->path)
                        return AVERROR(ENOMEM);
                    avio_read(pb, dref->path, len);
                    if (len > volume_len && !strncmp(dref->path, dref->volume, volume_len)) {
                        len -= volume_len;
                        memmove(dref->path, dref->path+volume_len, len);
                        dref->path[len] = 0;
                    }
                    for (j = 0; j < len; j++)
                        if (dref->path[j] == ':')
                            dref->path[j] = '/';
                    av_log(c->fc, AV_LOG_DEBUG, "path %s\n", dref->path);
                } else if (type == 0) { // directory name
                    av_free(dref->dir);
                    dref->dir = av_malloc(len+1);
                    if (!dref->dir)
                        return AVERROR(ENOMEM);
                    avio_read(pb, dref->dir, len);
                    dref->dir[len] = 0;
                    for (j = 0; j < len; j++)
                        if (dref->dir[j] == ':')
                            dref->dir[j] = '/';
                    av_log(c->fc, AV_LOG_DEBUG, "dir %s\n", dref->dir);
                } else
                    avio_skip(pb, len);
            }
        }
        avio_seek(pb, next, SEEK_SET);
    }
    return 0;
}

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.