OWASP Backend Security Project Oracle Hardening

= Overview =

= Description =

Installation security
This section is useful to understand how the installation will introduce vulnerabilities if it is not made “security oriented”.

Options and products
The Oracle Database installation pack contains a lot of options and products beside to the database server, so a custom installation should be done to avoid installing options and products not needed. The Oracle components other than the list below should be removed if not specifically required by any database applications.

Sample schemas
Oracle Corporation provides sample schemas in order to provide a common platform for examples. Review, after the installation, installed schema and remove any schema you do not need, using the follow SQL statement:

SQL> DROP USER  CASCADE;

Patching
You should keep up to date the Oracle Database therefore, periodically, you should check the Oracle Technology Network web site (http://otn.oracle.com/deploy/security/alerts.htm) to keep up on security alerts issued from Oracle Corporation in regard to all installed components.

Sometime, there are public vulnerility about Oracle software without a patch so it is a good idea subscribe to the security mailing lists so that you will be able to catch those new security issues and to find a way to mitigate the risk of the new vulnerability.

Initialization parameters
This section cover the Oracle Initialization parameters that are relevant for the security aspects. All the following initialization parameters have to be specified for all Oracle instances.

Example SQL for setting the REMOTE_OS_AUTHENTICATION parameter:

SQL> ALTER SYSTEM SET REMOTE_OS_AUTHENTICATION = FALSE SCOPE=BOTH

Scope:
 * MEMORY: This value change the instance immediately, but the configuration is lost after a restart.
 * SPFILE: This value NOT change the instance immediately, but a restart is necessaty to take effect.
 * BOTH:  This value change the instance immediately as well as the spfile.

Owner account
The Oracle OS installation account, owner of all Oracle application and datafiles, should be used only for the update and maintenance of the Oracle software and will not be used during the standard DBA activities. The individual DBAs will have to use their assigned OS personal accounts, so the auditing process will be able to actions performed with the correct OS account. The Oracle software installation account will not be a member of the administrative group.

Files and directories
All files and directories generated during the installation process of Oracle will be restricted to the Oracle software owner or the DBA OS user group, especially the file list below:

Other accounts should be denied access except to executables under the “bin” directory as specifically required. All files stored in the “bin” directory will be owned by the Oracle software installation account. These files and directories will be secured by using access control methods native to the operating system.

Lock and expire unused accounts
A number of default database server user accounts are create during the installation process so, if you do not use the Database Configuration Assistant, you should lock and expire all default database user accounts. Unlock only those accounts that need to be accessed on a regular basis and assign a strong password to each of these unlocked accounts.

Example SQL for reviewing the Oracle Default Accounts with status “OPEN”:

SQL> SELECT  FROM dba_users WHERE account_status <> ’OPEN’ ORDER BY ;

Example SQL for Locking Accounts:

SQL> ALTER USER  ACCOUNT LOCK;

Change default password
The major weakness concerning the password is that some user default account, after the installation, still has a default password associated with it, so you should be review the passwords of all default accounts (SYS, SYSTEM, DBSNMP, OUTLN and so on) and change it if necessary.

Enforce password policy
The password policy should be enforced by password verification function setting password parameter (list below) and providing password complexity feature like minimum length, password not same as the username, the password contains repeating characters, the password differs from the previous password by at least a maximal number of letters.

Example SQL for setting a password verification function to a profile:

SQL> CREATE PROFILE  LIMIT PASSWORD_VERIFICATION_FUCTION

Example SQL for assigning profile profile to a user:

SQL> CREATE USER  IDENTIFIED BY PROFILE ;

Encrypt network logins
The password information in a connection request should be encrypted to protect against network eavesdropping. The value of the follow parameter should be review:

ORA_ENCRYPT_LOGIN (on the client machine) DBLINK_ENCRYPT_LOGIN (on the server machine)

Once these parameters have been set to TRUE, passwords will be encrypted in connection requests. Note that on Oracle version 9.02 and later these parameter are not available, in fact it is encrypt automatically the password information when transmitting over a network, although the setting or changing of passwords is NOT encrypted when across the network.

Protect network communications
It is a good idea use the Oracle Advanced Security to use Secure Socket Layer (SSL) as to encrypt network traffic between clients and databases. Enable the protection about network communication by following the next step:

...

XML database (XDB) protocol server
The XML Database (XDB) offers access to the Oracle XML DB resources using the standard Internet protocols FTP, listening on TCP port 2100, and HTTP, listening on TCP port 8080. The Oracle XML DB Protocol Server is a specific type of Oracle shared server dispatcher and is specified in the Oracle database initialization parameter file for startup, so if XDB is not used it should be turned off editing the init.ora or spfile.ora (replace SID with the name of your SID) file and remove or comment the follow line:

dispatchers="(PROTOCOL=TCP) (SERVICE=XDB)"

If access via the Internet protocols is required, logging should be enabled by setting the “ftp-log-level” and “http-log-level” parameters to a value of 1 in xdbconfig.xml file.

Password
A listener password should be set at the end of listener configuration process to avoid from unauthorized start, stop, and configure. The password will be stored in encrypted format within the listener.ora file by using the LSNRCTL utility:

LSNRCTL> set current_listener  LNSRCTL> set password Password: (type "enter" if it is the first time) The command completed successfully LSNRCTL> change_password Old password: (type "enter") New password:  Reenter new password:  […]  The command completed successfully LSNRCTL> save_config (important to save the configuration) […]  Saved LISTENER configuration parameters. Listener Parameter File […] Old Parameter File […] The command completed successfully LSNRCTL> exit

Admin restrictions
The remote administration of the Oracle listener should be prevent by setting to TRUE the ADMIN_RESTRICTIONS parameter in the listener.ora file:

ADMIN_RESTRICTIONS_ = TRUE

Network address restriction
The network address restrictions should be enforced by the Oracle listener to further protect your database from unauthorized remote access. Network address restriction is required when the PLSQL EXTPROC is in use to protect against unauthenticated access to the database. To enable network address restriction, edit the SQLNET.ORA to add the follow line:

TCP.VALIDNODE_CHECKING = YES

Then, to defines TCP/IP addresses that are allowed to connect to database add the follow line:

TCP.INVITED_NODES = 

At the end, to defines TCP/IP addresses that are refused connections to the database set the follow parameter

TCP.EXCLUDED_NODES = 

Inbound connection timeout
The amount of time the listener waits for a network client to complete the connection request should be manage to prevent a denial of service attack. The name of parameter to set to configure inbound connection timeout and the name of the file of configuration, depends on Oracle version.

Audit
= References =

[1] The Oracle Hacker's Handbook: Hacking and Defending Oracle by David Litchfield

[2] The Database Hacker's Handbook: Defending Database Servers by David Litchfield

[3] Database Security Technical Implementation Guide by DISA for the DOD

[4] Oracle Database Security Guide by Oracle Corporation

[5] Oracle Database Security Checklist by Oracle Corporation