Stephen Kost's E-Business Suite Security Blog
Oracle 12c Real Application Security and Standard Database Auditing - Warning Database Logins Not Logged
Oracle 12c introduces several major new security features. Data redaction is one new feature and Real Application Security (RAS) is another. Per Oracle, RAS is the next generation Virtual Private Database (VPD) and is installed with Oracle Enterprise Edition – no additional license required. RAS is a new declarative and granular authorization model and is designed to be an application security platform for end-to-end application security. For those developing APEX applications (also installed with Enterprise Edition), RAS will certainly become an integral tool.
With RAS, developers define security policies instead of having to create and maintain PL/SQL code. Most notably, RAS however extends the security solution to define both application users and roles separate from database users and roles.
RAS allows for the creation of users, complete with user names and passwords, and stores them in the database. RAS users are not stored in DBA_USERS. RAS users are defined in DBA_XS_USERS, and their passwords are stored in SYS. XS$VERIFIERS.
With 126.96.36.199, RAS users can also directly connect to the database. It appears that with 188.8.131.52, RAS users can be defined with a flag to allow or disallow direct database logons. As any database security monitoring and logging solution should be monitoring database logon activity, it should be known that RAS users will NOT show up in standard Oracle database auditing. Standard database auditing instead picks up login activity by the generic user XS$NULL. Because it is designed to be part of an application, RAS has its own logging and auditing solution.
Basic logon activity for RAS users, however is logged in SYS.UNIFIED_AUDIT_TRAIL. Even if you have NOT enabled Unified Auditing in 12c, SYS.UNIFIED_AUDIT_TRAIL is being populated. Why this is the case will be the topic of another blog post. If you have compliance requirements to log and audit database logons, you will need to monitor SYS.UNIFIED_AUDIT_TRAIL for RAS user activity as well as for the creation of RAS users if not also potentially configuring RAS auditing. The example below should get you started.
With the below you can test for yourself how standard database auditing logs RAS user logons:
- Ensure auditing for create session is enabled, if not: audit create session by access;
- Create Real application security user
- Set password for Real Application Security user
- Review both dba_users and dba_xs_users to see for yourself where RAS users are defined.
- Log into the database with: INTEGRIGY_RAS_USER/oracle
- Look at your auditing and see a logon from XS$NULL instead of INTEGRIGY_RAS_USER
select * from sys.aud$ order by 1 desc
- Now look at SYS.UNIFIED_AUDIT_TRAIL. You will see XS$NULL for the DBUSERNAME but you will see 'INTEGRIGY_RAS_USER' in XS_USER_NAME.
select dbusername,xs_user_name ,event_timestamp
where xs_user_name = 'INTEGRIGY_RAS_USER'
order by event_timestamp
If you are not familiar with XS$NULL, XS$NULL is created when the database component Oracle XML Database (XDB) is installed. XDB is now a mandatory component of 12c and as such, XS$NULL must exist in the database. Per Oracle, XS$NULL is an internal account that represents the absence of a user in a session. It is used by the lightweight session infrastructure for APEX, RAS and XDB and the name of this user is hard coded in those modules. Because XS$NULL is not really a user, this account can only be accessed by the Oracle Database instance. XS$NULL has no privileges, and no one can authenticate as XS$NULL, nor can authentication credentials ever be assigned to XS$NULL.
If you have questions, please contact us at email@example.comReferences
Summary of Real Application Security http://www.oracle.com/technetwork/database/security/real-application-security/real-application-security-1964775.html
Oracle Documentation for Real Application Security http://docs.oracle.com/database/121/DBFSG/intro.htm#DBFSG10000
Is the XS$NULL user a required account? (Doc ID 1556725.1) https://support.oracle.com/rs?type=doc&id=1556725.1
UTL_FILE_DIR is the database initialization parameter the Oracle Database uses to determine what operating system directories and files PL/SQL packages, functions, and procedures may read from or write to when using the standard UTL_FILE database package. The directories specified in the UTL_FILE_DIR parameter may be accessed by any database user, which can be a security issue. In Oracle 9iR2, Oracle released new functionality called “Directories” that provides a more secure and robust capability to access operating system directories and files. The advantages of using Directories over UTL_FILE_DIR are –
- Read and/or Write access to a Directory can be granted to individual database accounts or roles
- A Directory can be added without having to bounce the database
- Directory name is used in the UTL_FILE.FOPEN statement rather than the directory path, which allows changes to the directory path without modification to the PL/SQL source code
The UTL_FILE database package is used to read from and write to operating system directories and files. By default, PUBLIC is granted execute permission on UTL_FILE. Therefore, any database account may read from and write to files in the directories specified in the UTL_FILE_DIR database initialization parameter.
Oracle usually assumes that PUBLIC has execute permission on UTL_FILE, therefore, many Oracle product installations do not specifically grant execute permission on UTL_FILE to Oracle installed database accounts. Consequently, revoking execute permission on UTL_FILE from PUBLIC will result in errors in a number of standard Oracle database utilities and The Oracle E-Business Suite. Also, some Oracle products and third party products will grant execute on UTL_FILE to PUBLIC during the installation of the product.
We do not recommend revoking execute permission on UTL_FILE from PUBLIC in database instances running the Oracle E-Business Suite and other complex applications (i.e., SAP, Peoplesoft, Oracle Clinical, etc.) due to the possibility of encountering errors in the application and third party products. Only revoke execute permission from PUBLIC in database instances where the application, third party products, and all database management tools can be thoroughly tested. All Oracle delivered products must be tested since Oracle often assumes UTL_FILE is granted to PUBLIC and does not provide the necessary grants when any products are installed – this includes products like Enterprise Manager Grid Control and Apex.
Security considerations with UTL_FILE can be mitigated by removing all directories from UTL_FILE_DIR and using the Directory functionality instead.Oracle E-Business Suite and UTL_FILE_DIR
The combination of UTL_FILE being granted to PUBLIC and UTL_FILE_DIR being publicly accessible creates a significant security issue for the Oracle E-Business Suite. The Oracle E-Business Suite uses UTL_FILE_DIR to read and write concurrent manager request temporary files. Also, UTL_FILE_DIR is extensively used by most organizations to access interface and conversion data files from PL/SQL interface programs.
In the Oracle E-Business Suite, UTL_FILE_DIR is usually set to include at least the directories specified in $APPLPTMP and $APPLTMP – in the default installation this will include at least “/usr/tmp”. Frequently, additional custom directories will be included for custom interfaces and other custom programs.
By accessing the APPLSYSPUB database account, an attacker can easy read and write interface data files. Depending on the exact configuration, implemented modules, and custom interfaces, this could allow access to sensitive information including social security numbers and credit card numbers.Migrating From UTL_FILE_DIR
For Oracle E-Business Suite customers, migrating from UTL_FILE_DIR to Directories requires only minimal changes and may require no source code changes depending on the design of the interfaces and other custom programs. The steps are as follows -
- Identify where UTIL_FILE is used
- Create Directories
- Change FOPEN calls to use Directories
- Edit UTL_FILE_DIR to remove physical Directories
Step One – Identify Where UTIL_FILE Is Used
The most difficult issue is identifying the packages, functions, and procedures using the physical directories in UTL_FILE_DIR. The UTL_FILE_DIR physical directories are only directly referenced by the UTL_FILE.FOPEN function. The FOPEN specifies the operating system directory and file name to open. All subsequent read, write, and close function calls use the file handle returned by FOPEN.
The following SQL may assist in identifying uses of UTL_FILE_DIR in FOPEN statements –
SELECT * FROM dba_source WHERE upper(text) like '%FOPEN%' AND name like '%<custom prefix>%' AND owner = 'APPS'
If the calls to FOPEN are not in a common function and are not accessed through some other indirection, it should be fairly straightforward to find and change the necessary FOPEN references in any custom PL/SQL packages, functions, and procedures. If the physical directory paths are stored in a table or in a concurrent program definition, then no changes to the source code are required.
At this time, converting the standard the Oracle E-Business Suite directories ($APPLPTMP and $APPLTMP) is not recommended as this is not supported by Oracle. Theoretically it should work without any issues, however, the Oracle E-Business Suite references the directories in multiple places including the $APPLPTMP and $APPLTMP environmental variables, system profile options (e.g., “ECX: XSLT File Path”), and potentially in some configuration files.
Step Two – Create Directories
The following general steps are required to change the references from UTL_FILE_DIR to Directories. Please note that the directory name MUST always be in uppercase in all UTL_FILE.FOPEN statements, otherwise errors may be encountered
For each custom directory in UTL_FILE_DIR, execute the following SQL statements in each development, test, and production database instance –
CREATE OR REPLACE DIRECTORY <name> AS '<physical directory path>';
GRANT READ, WRITE ON DIRECTORY <name> TO APPS;
as an example –
CREATE OR REPLACE DIRECTORY TMP_DIR AS '/usr/tmp';
GRANT READ, WRITE ON DIRECTORY TMP_DIR TO APPS;
The directories “/usr/tmp” and “../comn/temp” and any other directories specified in $APPLPTMP and $APPLTMP should remain in UTL_FILE_DIR, since these directories are required by Oracle.
Step Three – Change FOPEN Calls to Use Directories
Once directories have been created the next step is to edit your code to use them. The process is straightforward. If a physical directory is specified in the UTL_FILE.FOPEN statement, change the hard-coded path to the Directory name.
As an example –
FILE_ID := UTL_FILE.FOPEN('/usr/tmp', 'dummy.txt', 'W');
change to –
FILE_ID := UTL_FILE.FOPEN('TMP_DIR', 'dummy.txt', 'W');
Two pointers to keep in mind:
- Always be sure to use the directory name in uppercase and it must be enclosed in single quotes
- If the physical directory is specified in a table or as a parameter in a Concurrent Program definition, then just specify the Directory name rather than a physical path – /usr/tmp becomes TMP_DIR
Step Four – Edit UTL_FILE_DIR to Remove Physical Directories
Remove all the custom physical directories from UTL_FILE_DIR. The standard Oracle directories of ‘/usr/tmp’, ‘../comn/temp’, etc. should not be removed. The database must be bounced for the change to take effect.
If you have questions, please contact us at firstname.lastname@example.orgReferences
- Using CREATE DIRECTORY Instead of UTL_FILE_DIR init.ora Parameter”, Oracle Metalink, Metalink Note ID 196939.1 https://support.oracle.com/rs?type=doc&id=196939.1
In our blog post on 16-May, we provided guidance on Java JAR signing for the E-Business Suite. We are continuing our research on E-Business Suite Java JAR signing and will be presenting it in a forthcoming educational webinar. Until then we would like to share a few items of importance based on recent client conversations -
- Apply latest patches - The latest patches for Oracle E-Business Suite JAR signing are noted in 1591073.1. There are separate patches for 11i, 12.0.x, 12.1.x and 12.2.x. To fully take advantage of the security features provided by signing JAR files the latest patches need to be applied.
- Do not use the default Keystore passwords - Before you sign your JAR files change the keystore passwords. The initial instructions in 1591073.1 note that a possible first step before you start the JAR signing process is to change the keystore passwords. Integrigy recommends that changing the keystore passwords should be mandatory. The default Oracle passwords should not be used. Follow the instructions in Appendix A of 1591073.1 to change both keystore passwords. Each password must be at least six (6) characters in length. If you have already signed your JAR files, after changing the keystore passwords you must create a new keystore and redo all the steps in 1591073.1 to create a new signed certificate (it is much easier to change the keystore passwords BEFORE you sign your JAR files).
- The keystore passwords are available to anyone with the APPS password - Using the code below anyone with the APPS password can extract the keystore passwords. Ensure that this fact is allowed for in your polices for segregation of duties, keystore management and certificate security.
SQL> set serveroutput on
This will output the passwords in the following order:
store password (spass)
key password (kpass)
If you have questions, please contact us at email@example.comReferences
- 16-May-2014 Integrigy Blog post Oracle E-Business Suite Security - Signed JAR Files - What Should You Do
- Enhanced JAR Signing for Oracle E-Business Suite, 19-March-2014, Doc ID 1591073.1 https://support.oracle.com/rs?type=doc&id=1591073.1
- Oracle Tutorial on Java JAR signing: http://docs.oracle.com/javase/tutorial/deployment/jar/intro.html
Maintaining a secure Oracle E-Business Suite implementation requires constant vigilance. For the desktop clients accessing Oracle E-Business Suite, Integrigy recommends running the latest version of Java 7 SE. Java 7 is fully supported by Oracle with Public Updates through April 2015 and is patched with the latest security fixes. Most likely in late 2014 we anticipate that Oracle will have released and certified Java 8 with the Oracle E-Business Suite.
Most corporate environments utilize a standardized version of Java, tested and certified for corporate and mission critical applications. As such the Java auto-update functionality cannot be used to automatically upgrade Java on all desktops. These environments require new versions of Java to be periodically pushed to all desktops. For more information on how to push Java updates through software distribution see MOS Note 1439822.1. This note also describes how to download Java versions with the Java auto-update functionality disabled.
Keep in mind too that the version of Java used with the E-Business Suite should be obtained from My Oracle Support. Your Desktop support teams may or may not have Oracle support accounts.
Other points to keep in mind:
- To support Java 7, the Oracle E-Business Suite application servers must be updated per the instructions in MOS Note 393931.1
- “Non-Static Versioning” should be used the E-Business Suite to allow for later versions of the JRE Plug-in to be installed on the desktop client. For example, with Non-Static versioning JRE 7 will be invoked instead of JRE 6 if both are installed on a Windows desktop. With Non-Static versioning, the web server’s version of Java is the minimum version that can be used on the desktop client.
- You will need to implement the Enhanced JAR File signing for the later versions of Java 7 (refer to Integrigy blog posting for more information)
- Remember to remove all versions of Java that are no longer needed – for example JIinitiator
You may continue using Java 6. As an Oracle E-Business Suite customer, you are entitled to Java 6 updates through Extended Support. The latest Java 6 update (6u75) may be downloaded from My Oracle Support. This version (6u75) is equal to 7u55 for security fixes.
If you have questions, please contact us at firstname.lastname@example.orgReferences
- Oracle E-Business Suite Security - Signed JAR Files - What Should You Do
- All Java SE Downloads on MOS https://support.oracle.com/rs?type=doc&id=1439822.1
- Deploying JRE for Windows Clients in EBS R12 https://support.oracle.com/rs?type=doc&id=393931.1
- Static vs. Non-static Versioning and Set Up Options See Appendix B in https://support.oracle.com/rs?type=doc&id=393931.1
Tags: Security Strategy and StandardsOracle E-Business SuiteIT Security
Clients often contact Integrigy requesting assistance to protect their sensitive data. Frequently these are requests for assistance to locate and then encrypt sensitive data. While encryption offers protection for sensitive data, it by no means solves all security problems. How to protect sensitive data (and how to verify the trust of privileged users such as database administrators with sensitive data) requires more than just encryption.
The Oracle Database Security Guide (a great read for anyone interested in Oracle database security) makes three key points in Chapter Eight about encryption:
- Encryption does not solve access control problems - A user who has privileges to access data within the database has no more nor any less privileges as a result of encryption
- Encryption does not protect against a malicious database administrator - If untrustworthy users have significant privileges, then they can pose multiple threats to an organization, some of them far more significant than viewing unencrypted credit card numbers
- Encrypting everything does not make data secure – Data must be available when needed as well as backups and DR solutions considered. Moreover, encrypting all data will significantly affect performance.
Besides encryption, one of the security tools that Oracle provides is the DBMS_SQLHASH package. Hash values are similar to data fingerprints and can be used to validate if data has been changed (referred to as data integrity). Hashing is different from encryption and it is important to know the difference. If you need to know more about hashing, see the reference section below.
DBMS_SQLHASH package has been delivered since 10g and provides an interface to generate the hash value of the result set returned by a SQL query and provides support for several industry-standard hashing algorithms including SHA-1.
DBMS_SQLHASH.GETHASH(sqltext IN varchar2,
digest_type IN BINARY_INTEGER,
chunk_size IN number DEFAULT 134217728)
The SQL statement whose result is hashed
Hash algorithm used: HASH_MD4, HASH_MD5 or HASH_SH1
Use 3 for HASH_SH1, Use 2 for HASH_MD5 and 1 for HASH_MD4
Size of the result chunk when getting the hash
When the result set size is large, the GETHASH function will break it into chunks having a size equal to chunk_size. It will generate the hash for each chunk and then use hash chaining to calculate the final hash. The default chunk_size is 128 MB.
How Can Auditors use DBMS_SQLHASH
One use case for DBMS_SQLHASH is to help auditors trust-but-verify the actions of privileged users such as database administrators. By hashing key tables an auditor can quickly determine if the database administrator has made changes – either authorized or unauthorized. An auditor can do this by recording hashes at the start of an audit period for comparison to hashes at the end of the period. If the hashes at the end of the audit period match the hashes at the beginning of the period, no changes have been made. If there are a large number of databases and/or tables to audit, this approach is a very beneficial means of identifying what requires additional review – assuming sufficient logging has been configured to capture the details of the changes.
For example, to determine if there have been changes to Oracle database users and their associated privileges over a period of time, such as granting access to sensitive data, an auditor can hash the following Dictionary tables:
Note: to call the SYS.DBMS_SQLHASH package, the user will need execute rights granted from SYS.
SELECT SYS.DBMS_SQLHASH.GETHASH ('SELECT * FROM SYS.DBA_USERS ORDER BY USER_ID', 3) sh1_dba_user_hash FROM DUAL;
SELECT SYS.DBMS_SQLHASH.GETHASH('SELECT * FROM SYS.DBA_ROLES ORDER BY ROLE', 3) sh1_dba_roles_hash FROM DUAL;
SELECT SYS.DBMS_SQLHASH.GETHASH('SELECT * FROM SYS.DBA_TAB_PRIVS ORDER BY OWNER,TABLE_NAME', 3) sh1_dba_tab_privs_hash FROM DUAL;
SELECT SYS.DBMS_SQLHASH.GETHASH('SELECT * FROM SYS.DBA_SYS_PRIVS ORDER BY GRANTEE, PRIVILEGE', 3) sh1_dba_sys_privs_hash FROM DUAL;
SELECT SYS.DBMS_SQLHASH.GETHASH('SELECT * FROM SYS.DBA_ROLE_PRIVS ORDER BY GRANTEE, GRANTED_ROLE', 3) sh1_dba_role_privs_hash FROM DUAL;
The order by clause will change the HASH. Oracle Support Note 1569256.1 explains this in more detail. To guarantee the same HASH for a SQL issued at different times, the same ordering of the data must be used.
If you have questions or are interested in Integrigy's hashing methodology for Oracle and the Oracle E-Business Suite, please contact us at email@example.comReferences
- Oracle Database Security Guide 11g (chapter 8) http://docs.oracle.com/cd/E25054_01/network.1111/e16543/data_encryption.htm
- DBMS_SQLHASH Does Not Produce The Same Value In All Cases https://support.oracle.com/rs?type=doc&id=1569256.1
- What is a cryptographic hash function? http://en.wikipedia.org/wiki/Cryptographic_hash_function
- Great explanation on the differences between encryption and hashing http://www.youtube.com/watch?v=FYfMZx2hy_8