static void process_bin_stat(conn *c) {
    char *subcommand = binary_get_key(c);
    size_t nkey = c->binary_header.request.keylen;

    if (settings.verbose > 1) {
        int ii;
        fprintf(stderr, "<%d STATS ", c->sfd);
        for (ii = 0; ii < nkey; ++ii) {
            fprintf(stderr, "%c", subcommand[ii]);
        }
        fprintf(stderr, "\n");
    }

    if (nkey == 0) {
        /* request all statistics */
        server_stats(&append_stats, c);
        (void)get_stats(NULL, 0, &append_stats, c);
    } else if (strncmp(subcommand, "reset", 5) == 0) {
        stats_reset();
    } else if (strncmp(subcommand, "settings", 8) == 0) {
        process_stat_settings(&append_stats, c);
    } else if (strncmp(subcommand, "detail", 6) == 0) {
        char *subcmd_pos = subcommand + 6;
        if (strncmp(subcmd_pos, " dump", 5) == 0) {
            int len;
            char *dump_buf = stats_prefix_dump(&len);
            if (dump_buf == NULL || len <= 0) {
                write_bin_error(c, PROTOCOL_BINARY_RESPONSE_ENOMEM, 0);
                return ;
            } else {
                append_stats("detailed", strlen("detailed"), dump_buf, len, c);
                free(dump_buf);
            }
        } else if (strncmp(subcmd_pos, " on", 3) == 0) {
            settings.detail_enabled = 1;
        } else if (strncmp(subcmd_pos, " off", 4) == 0) {
            settings.detail_enabled = 0;
        } else {
            write_bin_error(c, PROTOCOL_BINARY_RESPONSE_KEY_ENOENT, 0);
            return;
        }
    } else {
        if (get_stats(subcommand, nkey, &append_stats, c)) {
            if (c->stats.buffer == NULL) {
                write_bin_error(c, PROTOCOL_BINARY_RESPONSE_ENOMEM, 0);
            } else {
                write_and_free(c, c->stats.buffer, c->stats.offset);
                c->stats.buffer = NULL;
            }
        } else {
            write_bin_error(c, PROTOCOL_BINARY_RESPONSE_KEY_ENOENT, 0);
        }

        return;
    }

    /* Append termination package and start the transfer */
    append_stats(NULL, 0, NULL, 0, c);
    if (c->stats.buffer == NULL) {
        write_bin_error(c, PROTOCOL_BINARY_RESPONSE_ENOMEM, 0);
    } else {
        write_and_free(c, c->stats.buffer, c->stats.offset);
        c->stats.buffer = NULL;
    }
}

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.