SQL Server security for developers and DBAs

1. SQL Server Security in an Insecure World
Gianluca Sartori
@spaghettidba
sqlconsulting.it

2. Say thank you to our Sponsors :

3. Gianluca Sartori
 Independent SQL Server consultant
 SQL Server MVP, MCTS, MCITP, MCT
 Works with SQL Server since version 7
 DBA @ Scuderia Ferrari
 Blog: spaghettidba.com
 Twitter: @spaghettidba

4. Agenda
 Security Matters
 What should I protect?
 How can I prevent attacks?

5.  Data Breaches are Common
 Data Breaches are Costly
 $450.000- $850.000 for large business
 $35.000 - $65.000 for small businesses
 + Reputational damage
 + Legal risks
-- Source: UK Government
Security Matters

6. Security Matters
 Security must be considered from the start
 Securing afterwards is extremely costly
 Poorly secured ecosystems are not always possible to fix
 Security is a process, not a product
 No single “magic” solution
 Ongoing process
 Attackers get smarter
 Security must be stronger

7. Information Security Principles
CIA triad

8. Information Security Principles
 Confidentiality
 Information cannot be disclosed to unauthorized individuals
 Integrity
 Data cannot be modified in an unauthorized or undetected
manner
 Availability
 Information must be available when needed

9. What happens to insecure systems?
 Confidentiality
 Data leaks
 Integrity
 Unauthorized data modifications
 Frauds
 Availability
 Outages

10. Attack Methodology
1. Scan for Vulnerabilities / Access
2. Gain Access
3. Escalate Privileges
4. Maintain Access
5. Cover Tracks
Looks complicated? It’s not!

11. DEMO
How fast can a [poorly configured] system be
compromised?
… damn fast!

12. How can I prevent it?
Implement security policies at all levels
 Physical Security
 External Network
 Internal Network
 Host OS
 Application
 Database

13. Physical security
 Disallow physical access to the infrastructure
 Servers
 Console
 Ports
 Disks
 Clients
 DBA workstation   + L
 What about the cloud?
 Networking devices
 Switches
 Routers
 Cables

14. Network Security
 Exclude External network as far as possible
 Implement proper network segmentation
 vLANs separate servers in groups
 Role
 Sensitivity
 Reduce “implied trust” relationships between servers
 Users / Servers is NOT proper segmentation
 Encrypt communications

15. Host OS
 Regular patching
 Antivirus
 Configuration  security best practices
 Shut down unneeded services
 Reduce attack surface
 Permissions  Least Privilege
 Auditing
 Logging

16. Application
Application is the most vulnerable component in
the stack
 Secure from the start
 Thorough design and code security review
 Input validation
 Authentication
 Authorization
 Error handling
 Auditing
 Logging

17. SQL Injection

18. SQL Injection

19. SQL Injection
 Has been known for years
 …yet N.1 in OWASP TOP 10 security risks
 Easy to detect with automated tools (SQLmap)
 …yet very common in the wild
 Potentially destructive

20. Injection techniques
 OR-based injection
 Stacked queries injection
 UNION-based injection
 Error-based injection
 Boolean-based blind injection
 Time-based blind injection

21. DEMO
Let’s sneak in!!

22. SQL Injection –Fixes
 Use bind parameters
 Enforces parameter data type
 Is not affected by regional settings
 Allows complex input
 Aggressive input sanitation does not

23. SQL Injection – False fixes
 ORMs do not avoid it
 Stored Procedures do not avoid it
 Input validation is not enough
 Obfuscated attacks
 Headers / query strings can be manipulated
 Not limited to web applications
 NoSQL is vulnerable as well!
 .NET’s String.Format is just plain concatenation!!!

24. DEMO
Let’s break things!!

25. What happened?
 We damaged the database, the instance and the OS
because we could
 Apply least privilege
 At the Database level
 At the Instance level
 At the OS level
 … at every level!

26.  Authenticate the user or the application?
 Prefer Windows Authentication when possible
 No need to provide password
 No need to store passwords in config files
 SQL Authentication is less secure
 Clear text < SQL2005
 RC4 < SQL2012
 Password policies
SQL Server Security - Authentication

27. SQL Server Security - Authentication
 Passwords are problematic
 Users tend to forget
 Sticky Notes
 Same password, multiple places
 Have I been pwnd?
 Use passwords that you cannot remember
 Use a Password Safe
 Keepass Password Safe

28. SQL Server Security - Authorization
Principle of least privilege:
 Users must be granted only the privileges essential for
their work
 Typical scenario:
 users are granted sysadmin role
 users are granted db_owner role  very common!
 users are granted built-in database roles
 Security must be taken into account from the start!!!

29. SQL Server Security
Best Practices:
1. Create application specific roles with no privileges
2. Grant minimum needed permissions to roles
3. Add users to roles
4. Don’t grant permissions to users
5. Use application roles to enhance security
 Windows groups <> database roles
 NEVER, EVER grant server roles to “regular” users

30. SQL Server Security
Additional features:
 TDE: Transparent Data Encryption
Encrypts database files and backup files
 SSL Network Encryption
Encrypts the communications channel between SQL Server and
client computers

31. SQL Server 2016 New Security Features
 Always Encrypted
Column-Level encryption
Data is encrypted both at rest and in memory
Decryption happens on the client
 Row-Level Security
Filters rows available to users
 Dynamic Data Masking
Obfuscates sensitive information

32. Resources
 OWASP
http://www.owasp.org
 Security checklist for the Database Engine
http://msdn.microsoft.com/en-us/library/ff848778(v=SQL.105).aspx
 Troy Hunt’s blog
http://www.troyhunt.com
 Troy Hunt’s free Pluralsight webinar: Why SQL Injection
Remains the #1 Web Security Risk Today
http://www.troyhunt.com/2015/06/free-recorded-webinar-on-
pluralsight.html

33. Q&A
Questions?

34. Stick around for RAFFLE and the AFTER EVENT!
 All our volunteers and organisers do not get paid for organizing
this event – If you see them, please:
 Give them a hug
 Shake their hand
 Say thank you
 Spread the word
 Get involved yourself
 Don’t forget to thank the sponsors for their support
 Thank the speakers for donating their time, energy and
expenses
 Don’t forget the feedback!