static void process_bin_update(conn *c) {
    char *key;
    int nkey;
    int vlen;
    item *it;
    protocol_binary_request_set* req = binary_get_request(c);

    assert(c != NULL);

    key = binary_get_key(c);
    nkey = c->binary_header.request.keylen;

    /* fix byteorder in the request */
    req->message.body.flags = ntohl(req->message.body.flags);
    req->message.body.expiration = ntohl(req->message.body.expiration);

    vlen = c->binary_header.request.bodylen - (nkey + c->binary_header.request.extlen);

    if (settings.verbose > 1) {
        int ii;
        if (c->cmd == PROTOCOL_BINARY_CMD_ADD) {
            fprintf(stderr, "<%d ADD ", c->sfd);
        } else if (c->cmd == PROTOCOL_BINARY_CMD_SET) {
            fprintf(stderr, "<%d SET ", c->sfd);
        } else {
            fprintf(stderr, "<%d REPLACE ", c->sfd);
        }
        for (ii = 0; ii < nkey; ++ii) {
            fprintf(stderr, "%c", key[ii]);
        }

        fprintf(stderr, " Value len is %d", vlen);
        fprintf(stderr, "\n");
    }

    if (settings.detail_enabled) {
        stats_prefix_record_set(key, nkey);
    }

    it = item_alloc(key, nkey, req->message.body.flags,
            realtime(req->message.body.expiration), vlen+2);

    if (it == 0) {
        if (! item_size_ok(nkey, req->message.body.flags, vlen + 2)) {
            write_bin_error(c, PROTOCOL_BINARY_RESPONSE_E2BIG, vlen);
        } else {
            write_bin_error(c, PROTOCOL_BINARY_RESPONSE_ENOMEM, vlen);
        }

        /* Avoid stale data persisting in cache because we failed alloc.
         * Unacceptable for SET. Anywhere else too? */
        if (c->cmd == PROTOCOL_BINARY_CMD_SET) {
            it = item_get(key, nkey);
            if (it) {
                item_unlink(it);
                item_remove(it);
            }
        }

        /* swallow the data line */
        c->write_and_go = conn_swallow;
        return;
    }

    ITEM_set_cas(it, c->binary_header.request.cas);

    switch (c->cmd) {
        case PROTOCOL_BINARY_CMD_ADD:
            c->cmd = NREAD_ADD;
            break;
        case PROTOCOL_BINARY_CMD_SET:
            c->cmd = NREAD_SET;
            break;
        case PROTOCOL_BINARY_CMD_REPLACE:
            c->cmd = NREAD_REPLACE;
            break;
        default:
            assert(0);
    }

    if (ITEM_get_cas(it) != 0) {
        c->cmd = NREAD_CAS;
    }

    c->item = it;
    c->ritem = ITEM_data(it);
    c->rlbytes = vlen;
    conn_set_state(c, conn_nread);
    c->substate = bin_read_set_value;
}

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.