static int mov_read_cmov(MOVContext *c, AVIOContext *pb, MOVAtom atom)
{
#if CONFIG_ZLIB
    AVIOContext ctx;
    uint8_t *cmov_data;
    uint8_t *moov_data; /* uncompressed data */
    long cmov_len, moov_len;
    int ret = -1;

    avio_rb32(pb); /* dcom atom */
    if (avio_rl32(pb) != MKTAG('d','c','o','m'))
        return AVERROR_INVALIDDATA;
    if (avio_rl32(pb) != MKTAG('z','l','i','b')) {
        av_log(c->fc, AV_LOG_ERROR, "unknown compression for cmov atom !");
        return AVERROR_INVALIDDATA;
    }
    avio_rb32(pb); /* cmvd atom */
    if (avio_rl32(pb) != MKTAG('c','m','v','d'))
        return AVERROR_INVALIDDATA;
    moov_len = avio_rb32(pb); /* uncompressed size */
    cmov_len = atom.size - 6 * 4;

    cmov_data = av_malloc(cmov_len);
    if (!cmov_data)
        return AVERROR(ENOMEM);
    moov_data = av_malloc(moov_len);
    if (!moov_data) {
        av_free(cmov_data);
        return AVERROR(ENOMEM);
    }
    avio_read(pb, cmov_data, cmov_len);
    if (uncompress (moov_data, (uLongf *) &moov_len, (const Bytef *)cmov_data, cmov_len) != Z_OK)
        goto free_and_return;
    if (ffio_init_context(&ctx, moov_data, moov_len, 0, NULL, NULL, NULL, NULL) != 0)
        goto free_and_return;
    atom.type = MKTAG('m','o','o','v');
    atom.size = moov_len;
    ret = mov_read_default(c, &ctx, atom);
free_and_return:
    av_free(moov_data);
    av_free(cmov_data);
    return ret;
#else
    av_log(c->fc, AV_LOG_ERROR, "this file requires zlib support compiled in\n");
    return AVERROR(ENOSYS);
#endif
}

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.