_zip_read_eocd64(zip_source_t *src, zip_buffer_t *buffer, zip_uint64_t buf_offset, unsigned int flags, zip_error_t *error)
{
    zip_cdir_t *cd;
    zip_uint64_t offset;
    zip_uint8_t eocd[EOCD64LEN];
    zip_uint64_t eocd_offset;
    zip_uint64_t size, nentry, i, eocdloc_offset;
    bool free_buffer;
    zip_uint32_t num_disks, num_disks64, eocd_disk, eocd_disk64;

    eocdloc_offset = _zip_buffer_offset(buffer);

    _zip_buffer_get(buffer, 4); /* magic already verified */

    num_disks = _zip_buffer_get_16(buffer);
    eocd_disk = _zip_buffer_get_16(buffer);
    eocd_offset = _zip_buffer_get_64(buffer);

    if (eocd_offset > ZIP_INT64_MAX || eocd_offset + EOCD64LEN < eocd_offset) {
        zip_error_set(error, ZIP_ER_SEEK, EFBIG);
        return NULL;
    }

    if (eocd_offset + EOCD64LEN > eocdloc_offset + buf_offset) {
	zip_error_set(error, ZIP_ER_INCONS, 0);
	return NULL;
    }

    if (eocd_offset >= buf_offset && eocd_offset + EOCD64LEN <= buf_offset + _zip_buffer_size(buffer)) {
        _zip_buffer_set_offset(buffer, eocd_offset - buf_offset);
        free_buffer = false;
    }
    else {
        if (zip_source_seek(src, (zip_int64_t)eocd_offset, SEEK_SET) < 0) {
            _zip_error_set_from_source(error, src);
            return NULL;
        }
        if ((buffer = _zip_buffer_new_from_source(src, EOCD64LEN, eocd, error)) == NULL) {
            return NULL;
        }
        free_buffer = true;
    }

    if (memcmp(_zip_buffer_get(buffer, 4), EOCD64_MAGIC, 4) != 0) {
	zip_error_set(error, ZIP_ER_INCONS, 0);
        if (free_buffer) {
            _zip_buffer_free(buffer);
        }
	return NULL;
    }

    size = _zip_buffer_get_64(buffer);

    if ((flags & ZIP_CHECKCONS) && size + eocd_offset + 12 != buf_offset + eocdloc_offset) {
	zip_error_set(error, ZIP_ER_INCONS, 0);
        if (free_buffer) {
            _zip_buffer_free(buffer);
        }
        return NULL;
    }

    _zip_buffer_get(buffer, 4); /* skip version made by/needed */

    num_disks64 = _zip_buffer_get_32(buffer);
    eocd_disk64 = _zip_buffer_get_32(buffer);

    /* if eocd values are 0xffff, we have to use eocd64 values.
       otherwise, if the values are not the same, it's inconsistent;
       in any case, if the value is not 0, we don't support it */
    if (num_disks == 0xffff) {
	num_disks = num_disks64;
    }
    if (eocd_disk == 0xffff) {
	eocd_disk = eocd_disk64;
    }
    if ((flags & ZIP_CHECKCONS) && (eocd_disk != eocd_disk64 || num_disks != num_disks64)) {
	zip_error_set(error, ZIP_ER_INCONS, 0);
        if (free_buffer) {
            _zip_buffer_free(buffer);
        }
	return NULL;
    }
    if (num_disks != 0 || eocd_disk != 0) {
	zip_error_set(error, ZIP_ER_MULTIDISK, 0);
        if (free_buffer) {
            _zip_buffer_free(buffer);
        }
	return NULL;
    }

    nentry = _zip_buffer_get_64(buffer);
    i = _zip_buffer_get_64(buffer);

    if (nentry != i) {
	zip_error_set(error, ZIP_ER_MULTIDISK, 0);
        if (free_buffer) {
            _zip_buffer_free(buffer);
        }
	return NULL;
    }

    size = _zip_buffer_get_64(buffer);
    offset = _zip_buffer_get_64(buffer);

    if (!_zip_buffer_ok(buffer)) {
        zip_error_set(error, ZIP_ER_INTERNAL, 0);
        if (free_buffer) {
            _zip_buffer_free(buffer);
        }
        return NULL;
    }

    if (free_buffer) {
        _zip_buffer_free(buffer);
    }

    if (offset > ZIP_INT64_MAX || offset+size < offset) {
         zip_error_set(error, ZIP_ER_SEEK, EFBIG);
         return NULL;
     }
    if ((flags & ZIP_CHECKCONS) && offset+size != eocd_offset) {
 	zip_error_set(error, ZIP_ER_INCONS, 0);
 	return NULL;
     }

    if ((cd=_zip_cdir_new(nentry, error)) == NULL)
	return NULL;

    cd->is_zip64 = true;
    cd->size = size;
    cd->offset = offset;

    return cd;
}

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.