Database Security Overview Database Security 1 Introduction 2
Database Security
Overview Database Security 1) Introduction 2) DB Security Plan 3) Database Access Control 4) DBMS Security: Patching 5) DB Application: SQL injection, Inference Threats 6) Virtual Private Databases 7) Oracle Label Security 8) Inference Threats 9) Encryption 10) Auditing 11) Datawarehouse
1) Introduction - Motivation Database Security • “Securing the DB may be the single biggest action an organization can take to protect its assets” David C. Knox “Effective Oracle Database 10 g Security by Design”, Mc. Graw Hill, 2004. ISBN 0 -07 -223130 -0
1) Introduction - Scope Database Security • Database system security must worry about DB +… – Secure Database – Secure applications – Secure DBMS – Secure operating system in relation to database system – Secure web server in relation to database system – Secure network environment in relation to database system
1) Introduction - Literature Database Security AUTHOR Publisher ISBN Elsevier Digital Press 1 -5558 -334 -2 Afyouni, Hassan A. , Database Security (2006) and Auditing Thompson Course Technology 0 -619 -21559 -3 Effective Oracle Database 10 g Knox, David (2004) Security by Design Oracle Press 0072231300 Natan, Ron Ben 2005 TEXT Implementing Database Security and Auditing
1) Topics versus Books Database Security
![1) DB security books Database Security • • [1] Knox, David (2004), Effective Oracle](http://slidetodoc.com/presentation_image/31799dd363c28d9a3033c7c7810a944c/image-7.jpg "1) DB security books Database Security • • [1] Knox, David (2004), Effective Oracle")
1) DB security books Database Security • • [1] Knox, David (2004), Effective Oracle Database 10 g Security by Design, Mc. Graw-Hill. ISBN 007 -223130 -0 [5] Afyouni, Hassan A. (2006), Database Security and Auditing, Thompson Course Technology, 0 -619 -21559 -4. [6] Litchfield, “The Database Hacker’s Handbook: Defending Database Servers”, http: //www. amazon. com/gp/reader/0764578014/ref=sib_dp_pop_toc? ie=UTF 8&p=S 00 C# [7] Marlene Theriault & William Heney , http: //oreilly. com/catalog/orasec/chapter/ch 07. html Oracle Security. [8] Charles P. Pfleeger, Shari Lawrence Pfleeger, Security in Computing, Prentice Hall, ISBN-10: 0132390779, October 2006. 4 th ed. [9] Michael Howard , David Le. Blanc, Writing Secure Code, Microsoft Press, 2 nd edition, 2003, 2 nd edition, ISBN n. 0 -7356 -1722 -8. [10] Natan, Ron Ben (2005), Implementing Database Security and Auditing, Elsevier Digital Press, 1 -5558 -334 -2, 2005. [11] Finnigan, Pete. Oracle Security Step-by-Step, SANS Press, v. 2, 2004. • Note these are the references from the previous slide • You may also go to http: //adbc. kennesaw. edu (Database Courseware) and select the Security Module • • •
1) Introduction – Product Specific Books Database Security • Oracle Advanced Security (previously Advanced Network Option), contains network encryption tools. Depending on the version of Oracle, it is available for no extra cost. It is for the enterprise edition. • Best literature for OAS is Oracle Security Handbook by Marlene Theriault and Aaron Newman, Mc. Graw-Hill.
2) DB Security Plan Database Security http: //www. oreilly. com/catalog/orasec/chapter/ch 07. html
2) DB Security Plan Database Security Which is the most complex program/form to implement? If a data type is changed in the Customers table, what programs/forms may need modification? The Orders form accesses how many tables? The Employees table is accessed by how many programs/forms?
2) DB Security Plan Database Security Subjects • DAC Versus MAC • Access Matrix Model: Harrison-Ruzzo-Ullman – Authorized state: Q = (S, O, A) – Conditions (dependent) • Data • Time • Context • History Objects O 1 Oj Om S 1 A[S 1, O 1] A[S 1, Oj] A[S 1, Om] Si A[Si, O 1] A[Si, Oj] A[Si, Om] Sn A[Sn, O 1] A[Sn, Oj] A[Sn, Om]
2) DB Security Plan - Document User Database Security Administration • Part of the administration process • Reasons to document: – Provide a paper trail – Ensure administration consistency • What to document: – Administration policies, staff and management – Security procedures – Procedure implementation scripts or programs – Predefined roles description
3) DB Access Control Database Security • Default Users and Passwords – Users, Passwords • Default users/passwords – sys, system accounts – privileged, change default password – Sa (MS-SQL Server) – scott account – well-known account/password, change it - general password policies (length, domain, changing, protection) • People Having too many privileges – Privileges, Roles, Grant/Revoke • Privileges – System - actions – Objects – data • Roles (pre-defined and user-defined role) – Collections of system privileges (example: DBA role) • Grant / Revoke – Giving (removing ) privileges or roles to (from) users
3) DB Access Control - Default Passwords Database Security • Easiest way to log into an Oracle database is to use a default account with a known password [Finnigin] • http: //www. petefinnigan. com/default_password_checker. htm • This site has scripts that will identify all default users and lets you know if they still have their default passwords. You may download these scripts.
3) DB Access Control - Password Cracking Database Security • At http: //www. toolcrypt. org/index. html there are tools that you can download to crack the passwords. You need to verify this against the DB, because you can be sure that the hacker has these tools.
3) DB Access Control - Find all Privileges Database Security • http: //www. petefinnigan. com/find_all_privs. sql • Script to find which privileges have been granted to a particular user. This scripts lists ROLES, SYSTEM privileges and object privileges granted to a user. If a ROLE is found -- then it is checked recursively. • Output can be directed to the screen or to a file.
3) DB Access Control - Check for DBA Role Database Security
3) DB Access Control - How are privileges granted Database Security • DBMS like Oracle has pre-defined roles (ex: DBA) • You may also have user defined roles Example 1) Create Role Acct. Dept; 2) Grant Select, Update on Orders to Acct. Dept; 3) Grant Acct. Dept to Smith, Jones; 4) Grant DBA to Smith; Grant all privileges on Orders to Smith; Grant select on Orders to Public; Revoke delete on Orders from smith;
3) DB Access Control - Disable Account Database Security CREATE USER smith identified by s 9 default tablespace users; ALTER USER scott ACCOUNT LOCK -- lock a user account ALTER USER scott ACCOUNT UNLOCK; ALTER USER scott PASSWORD EXPIRE; -- Force new pwd
3) DB Access Control - Launch OEM Database Security • Choose stand-alone for personal Oracle and login to oracle using a dba user/password
3) DB Access Control - Connect to a Database Security • On the left side of the screen, double click Network and then Databases to connect to the database you want o manage.
3) DB Access Control - Maintain User Accounts Database Security • Once you login, you may create users, roles and profiles as well as granting privileges to them through a GUI interface.
3) DB Access Control - Profiles Database Security • PROFILE clause: indicates the profile used for limiting database resources and enforcing password policies. Example: • CREATE PROFILE app_user LIMIT SESSIONS_PER_USER UNLIMITED CPU_PER_SESSION UNLIMITED CPU_PER_CALL 3000 CONNECT_TIME 45 LOGICAL_READS_PER_SESSION DEFAULT LOGICAL_READS_PER_CALL 1000 PRIVATE_SGA 15 K COMPOSITE_LIMIT 5000000; • CREATE USER sidney IDENTIFIED BY out_standing 1 DEFAULT TABLESPACE demo QUOTA 10 M ON demo TEMPORARY TABLESPACE temp QUOTA 5 M ON system PROFILE app_user PASSWORD EXPIRE;
3) DB Access Control - Security MS-Access Database Security • Two methods for securing a database: – set password to open a database (system security); – user-level security, to limit the parts of the database that a user can read or update (data security).
3) DB Access Control - System Level: Open Exclusive Database Security
3) DB Access Control - System Level Security (cont. ) Database Security DBA Sets password User is prompted every time he/she opens the DB
3) DB Access Control - MS-Access: User Level Database Security
4) SECURE THE DBMS (Patch) Database Security • Possible Holes in DBMS – http: //technet. oracle. com/deploy/security/alert s. htm (50+ listed) – Buffer overflow problems in DBMS code – Miscellaneous attacks (Denial of Service, source code disclosure of JSPs, others) • Need for continual patching of DBMS – Cost of not patching Worms, virus, etc. SQL slammer worm
5) DB Applications Database Security • “ 75 percent of hacks happen at the application” – Gartner “Security at the Application Level”. • “The main battlefield between hackers and security professionals have moved from the network layer to the web applications” Eric Marvets, “Microsoft Security Summit”, April 13, 2006, Atlanta, Georgia
5) DB Applications - SQL Injection Database Security • Web Application where 1) User inputs text into a textbox 2) Text used to build SQL Query dynamically 3) Malicious input changes the nature of the query Example: user inputs names into textbox Name: Benjamin Franklin ' OR 1=1; Sql. Str = “SELECT * FROM EMPLOYEE WHERE EMPLOYEE. Name = ” + user. Input Sql. Str = SELECT * FROM EMPLOYEE WHERE EMPLOYEE. Name = 'Benjamin Franklin' OR 1 = 1; –Result: every row of the EMPLOYEE table will be returned
SQL Injection - Solution Database Security • Similar to Buffer overflow: validate user input.
6) Virtual Private Databases Database Security • May be implemented through Views in most Database Management Systems (DBMS) • In Oracle, you may create a policy that will be fired when an operation (Insert, Update, etc. ) is performed by a certain user on a certain object.
6) VPD, Example of Row Level Security w/ Views Database Security
6) VPD with a Policy Database Security
http: //bgoug. org/seminar-Velingrad-oct-2005/Presentations/Presentation_OLS. ppt Virtual Private Database Technology Database Security Data access via Virtual Private Database will perform the following five steps: 1. User sends SQL to the database server. 2. The associated table triggers a pre-defined security policy. 3. The security policy returns a predicate. 4. The SQL statement is modified according to the security policy. 5. Secured data returns to user.
6) VPD - Grant Execute on DBMS_RLS Database Security • CONNECT TO ORACLE AS SYSDBA SQL> connect sys as sysdba Enter password: ****** Connected. SYSDBA creates a user called SECMAN (Security manager) SQL> create user secman identified by s default tablespace users; SYSDBA GRANTS EXECUTE ON DBMS_RLS TO SECMAN so this user can create the VPD SQL> grant dba to secman; SQL> grant execute on dbms_rls to secman; CONNECT AS SECMAN SQL> connect secman/s;
VPD - Definition Database Security Ex. : SELECT * FROM Emp; -- becomes SELECT * FROM Emp where Emp. Name = User;
http: //bgoug. org/seminar-Velingrad-oct-2005/Presentations/Presentation_OLS. ppt Virtual Private Database Technology Database Security A VPD security model uses the Oracle dbms_rls package (RLS stands for row -level security) to implement the security policies and application contexts. This requires a policy that is defined to control access to tables and rows
6) VPD – Update Example Database Security Connecting Policy, Table and Function UPDATE mn 668 b 14. Employees set ext = 777; 1 row updated.
6) VPD - Security Policy Database Security -- create security policy BEGIN DBMS_RLS. drop_policy (object_schema => 'MN 668 B 14', object_name => ' Employee. Update. Order. View', policy_name => 'EMP_UPDATE_ORDERS_POLICY'); END; BEGIN dbms_rls. add_policy ( object_schema => 'MN 668 B 14', object_name => ' Employee. Update. Order. View ', policy_name => 'EMP_ORDERS_UPDATE__POLICY’, function_schema => 'MN 668 B 14', policy_function => 'EMPUSER_ONLY', statement_types => 'SELECT, UPDATE, INSERT, DELETE', update_check => TRUE ); END;
6) VPD - Summary Database Security • VPD security provides a new way to control access to Oracle data. • One Schema, several virtual schemas. • Dynamic nature of a VPD. At runtime, DBMS modifies SQL statement to add security. Burleson, Donald (2003), "Establish security policy with Oracle virtual private database", http: //www. dba-oracle. com/art_builder_vpd. htm
7) Oracle Label Security (OLS) Database Security • simulates multilevel db. • Adds a field for each row to store the row’s sensitive label. • Access is granted (or denied) comparing user’s identity and security clearance label with row’s sensitive label.
7) OLS and Multilevel Security Database Security • Information has different classifications • Users have different security clearances • Purpose: separate data based on its classification • Mandatory Access Control (MAC): security enforced by system and not by the user. • Polyinstantiation: multiple rows with same PK. Instances distinguished by security level.
7) Problem with Multilevel Security Database Security • It is really multiple instantiations of single-level DBMS, which strongly degrades performance. • Examples: Trusted Oracle, DB 2 for z/OS, Informix On. Line/Secure, Sybase secure system
7) Oracle Label Security: Database Security • simulates multilevel db. • Adds a field for each row to store the row’s sensitive label. • Access is granted (or denied) comparing user’s identity and security clearance label with row’s sensitive label. • Label contains LEVEL, GROUP and COMPARTMENT
7) OLS & VPD Database Security • Like VPD, OLS creates Policies • A policy is a name that associates labels, rules, and authorizations. • DBA defines a set of labels for data and users, along with authorizations for users and program units, that defines all access to objects.
7) OLS LABEL has 3 Components Database Security • level : mandatory, simple hierarchy • compartment optional, non-hierarchical • group optional, tree level hierarchy • OLS compares the user security clearance with the sensitivity label assigned to the data. • IF a label contains all 3 components, THEN the security clearance of the user >= the data sensitivity level, contain all compartments and at least one group.
7) OLS - More on 3 components Database Security • label has 3 components: • a single level (sensitivity) ranking • zero or more horizontal compartments • zero or more hierarchical groups
7) OLS – Column added Database Security • When an Oracle Label Security policy, a column is added to the table that is protected by the policy. This policy label column contains the label information for each data row. • DBA can choose to display or hide this column
7) OLS - Levels Database Security
7) OLS - Compartments Database Security
7) OLS - Groups Database Security
7) OLS & VPD Database Security • FGAC = Fine Grained Access Control (A mechanism to implement Row level security in Oracle Database) • OLS and VPD are the utilities which are used for FGAC. • OLS: GUI tool • ROW LEVEL SECURITY • COLUMN LEVEL SECUITY in Oracle 9 i, neither. use views. in Oracle 10 g you can o column masking with VPD, but not with OLS.
7) OLS Conclusion Database Security • Built on top of VPD • Higher Level, more refined than VPD • Built around Row Level Security, Not much for Column Level Security
8) Inference Threat Database Security
9) Encryption: overview Database Security • Encrypting Data-in-transit As it is transmitted between client-server • Encrypting Data-at-rest Storing data in the database as encrypted Encrypting of Data is another layer of security (security in depth). It does not substitute other DB security techniques such as strong password.
9) Encrypting Data-in-transit Database Security For a Hacker to eavesdrop on a conversation and steal data, two things may occur 1) Physically tap into the communications between the db client & the db server 2) Hacker must understand the communication stream in order to extract sensitive data. In order to do this, what does the Hacker need ?
Tools for packet sniffing Database Security the Hacker needs to have • With a minimum understanding of TCP/IP + • Use one of many network protocol analyzer that are freely available. • Packet (formatted block of data transmitted by a Network). • Sniffing: capturing and analyzing package (like dog sniffing).
Minimum Understanding of TCP/IP Database Security • Network Security book. Example: Roberta Bragg, Mark Rhodes-Ousley and Keith Strassberg, Network Security; The Complete Reference. • TCP/IP is well documented all over the web. • Documentation describes the headers of the packet.
9) Encryption - Where to run Network Analyzer Packet ? Database Security • Client Machine that has access to the Database server • Database Server
Network Protocol Analyzer: examples Database Security • Tcpdump: utility available as part of installation on most UNIX systems. Can be downloaded from http: //www. tcpdump. org • (windump). Windows counterpart. Available on some systems. Can be downloaded from http: //windump. polito. it • Wireshark (http: //www. wireshark. org/download. html): world’s most famous NP Analyzer. Formerly Ethereal (www. ethereal. com).
Implement Encryption, data-in-transit Database Security Fortunately there also many encryption techniques for data in transit: • Database-specific features such as Oracle Advanced Security • Connection-based metods (such as SSL) • Secure tunnels (such as SSH) • Relying on the operating Systems (IPSec Encryption)
Secure Socket Layer (SSL) Database Security • cryptographic protocols that provide secure communications on the Internet for such things as web browsing, e-mail, Internet faxing, instant messaging and other data transfers. • You may enable SSL from within a DBMS. • SQL-Server for example: Programs -> Microsoft SQL Server -> Server Network Utility, check the Force protocol Encryption checkbox. Then Stop and start SQL Server. • Server also must be informed how it will derive encryption keys • Note: make sure that your version of SSL is compatible with your version of My. SQL (like in ODBC or JDBC).
SSH Tunnels Database Security • SSH used in many applications. Example: Substitute for FTP with encryption. • From most DBMSs, you can set up SSH tunnels to encrypt database traffic by port forwarding (Encrypted session between client and server). • Example: to connect Linux client machine of IP CCC. C. CCC to a My. SQL instance installed on a server with IP address of SSS. S. SS listening in on port 3306 (default My. SQL port). • Ssh –L 1000: localhost: 3306 SSS. S. SS –l mylogin –I ~/. ssh id –N -g • -L=port forwarding, Any connection attempted on port 1000 on the local machine should be forwarded to port 3306 on the server. Therefore any connection on port 1000 will go through encryption.
IPSec Database Security • Another Infrastructure option that protects the DB with encryption tools. • IPSec is done by the OS so you need to encrypt all communications (can’t be selective). • It operates at layer 3 of the OSI network (lower level). Installing IPSec on Windows/XP • install IP Security Policy manager. Then from Control Panel -> Administrative Tools, select IPSec
Encrypting Data-at-rest Database Security • There are two reasons to do this – Protect it from DBAs. – Protect from File or Disk Theft.
Encrypting Data-at-rest Database Security • Encrypting at Application Layer Must do it at multiple locations from within app. Data can only be used from within application • Encrypting at File System/Operating System Layer less flexible. Requires you to encrypt everything. Performance degrades Weak for handling Disk Theft problem. • Encrypting within Database – Usually, most practical option
Encrypting at Application Layer Database Security • Application Developers use a cryptographic library to encrypt such as Java Cryptographic Extensions (JCE) – set of APIs in the java. security and java. crypto packages
Encryption at OS layer Database Security • Windows implements the Encrypted File System (EFS) and you can use it for MS-SQL Server. • Disadvantages ?
Encryption within Database Security • SQL Server 2005 you can access Windows Crypto. API through DB_ENCRYPT and DB_DECRYPT within T-SQL (similar to PL/SQL) Can use DES, Triple DES and AES (symmetric keys) • In ORACLE, you can access – DBMS_OBFUSCATION_TOOLKIT package that implements DES and Triple DES
Summary Database Security • DB Encryption can be divided into Data-in-transit and Data-at-rest • Encryption is useful as a last layer of defense (defense in depth). Should never be used as an alternative solution • Encryption should be used only when needed • Key Management is Key
10) Auditing Database Security • Need to be selective
2 main types of auditing: Database Security • Oracle-supplied auditing using AUDIT command. Results go to AUD$ • Trigger-based DML auditing • Either way, DBA must monitor auditing table. Auditing examples/scripts: • http: //www. securityfocus. com/infocus/1689 • http: //www. petefinnigan. com/papers/audit. sql
Example of Audit command Database Security • Must have audit system privileges • Only tracks in subsequent user sessions • Creates records in table AUD$ owned by sys – You don’t query this table, you query • Views such as DBA_AUDIT_TRAIL • • SQL> AUDIT Delete any table; NOAUDIT delete any table; AUDIT SELECT TABLE, UPDATE TABLE; AUDIT create session;
When to audit Database Security • When should we audit Oracle users ? – Basic set of auditing measures all the time – Capture user access, use of system privileges, changes to the db schema (DDL) If company handles sensitive data (financial market, military, etc. ) OR If there are suspicious activities concerning the DB or a user, specific actions should be done.
Audit w/ Triggers (generic solution) Database Security • Create a table that will contain audit information • Create a trigger that inserts a row into the table every time a certain operation is created such as LOGON, LOGOFF, CREATE TABLE, DELETE, etc.
11) Datawarehouses Database Security • Traditionally queried only by upper management • Encryption has not been an option due to performance implications • Designed as Open systems, permitting exploratory approach • Optimization techniques for quick responses
Datawarehouse Trends & Problems Database Security • Range of potential users are rapidly increasing • Number of security breaches are rapidly increasing • Legislation is addressing issue to protect personal information • Statistical Databases and Inferences User is allowed to see aggregate data, but not individual rows. With malicious input, user infers the value of individual rows.
End of Lecture Database Security End Of Today’s Lecture.
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