126.96.36.199 NDB Cluster and MySQL Security Procedures
In this section, we discuss MySQL standard security procedures as they apply to running NDB Cluster.
In general, any standard procedure for running MySQL securely also applies to running a MySQL Server as part of an NDB Cluster. First and foremost, you should always run a MySQL Server as the
mysql operating system user; this is no different from running MySQL in a standard (non-Cluster) environment. The
mysql system account should be uniquely and clearly defined. Fortunately, this is the default behavior for a new MySQL installation. You can verify that the mysqld process is running as the
mysql operating system user by using the system command such as the one shown here:
shell> ps aux | grep mysql root 10467 0.0 0.1 3616 1380 pts/3 S 11:53 0:00 \ /bin/sh ./mysqld_safe --ndbcluster --ndb-connectstring=localhost:1186 mysql 10512 0.2 2.5 58528 26636 pts/3 Sl 11:53 0:00 \ /usr/local/mysql/libexec/mysqld --basedir=/usr/local/mysql \ --datadir=/usr/local/mysql/var --user=mysql --ndbcluster \ --ndb-connectstring=localhost:1186 --pid-file=/usr/local/mysql/var/mothra.pid \ --log-error=/usr/local/mysql/var/mothra.err jon 10579 0.0 0.0 2736 688 pts/0 S+ 11:54 0:00 grep mysql
If the mysqld process is running as any other user than
mysql, you should immediately shut it down and restart it as the
mysql user. If this user does not exist on the system, the
mysql user account should be created, and this user should be part of the
mysql user group; in this case, you should also make sure that the MySQL data directory on this system (as set using the
--datadir option for mysqld) is owned by the
mysql user, and that the SQL node's
my.cnf file includes
user=mysql in the
[mysqld] section. Alternatively, you can start the MySQL server process with
--user=mysql on the command line, but it is preferable to use the
my.cnf option, since you might forget to use the command-line option and so have mysqld running as another user unintentionally. The mysqld_safe startup script forces MySQL to run as the
Never run mysqld as the system root user. Doing so means that potentially any file on the system can be read by MySQL, and thus—should MySQL be compromised—by an attacker.
As mentioned in the previous section (see Section 188.8.131.52, “NDB Cluster and MySQL Privileges”), you should always set a root password for the MySQL Server as soon as you have it running. You should also delete the anonymous user account that is installed by default. You can accomplish these tasks using the following statements:
shell> mysql -u root mysql> UPDATE mysql.user -> SET Password=PASSWORD('secure_password') -> WHERE User='root'; mysql> DELETE FROM mysql.user -> WHERE User=''; mysql> FLUSH PRIVILEGES;
Be very careful when executing the
DELETE statement not to omit the
WHERE clause, or you risk deleting all MySQL users. Be sure to run the
FLUSH PRIVILEGES statement as soon as you have modified the
mysql.user table, so that the changes take immediate effect. Without
FLUSH PRIVILEGES, the changes do not take effect until the next time that the server is restarted.
Many of the NDB Cluster utilities such as ndb_show_tables, ndb_desc, and ndb_select_all also work without authentication and can reveal table names, schemas, and data. By default these are installed on Unix-style systems with the permissions
wxr-xr-x (755), which means they can be executed by any user that can access the
See Section 21.4, “NDB Cluster Programs”, for more information about these utilities.