SQL Injection Attacks: Is Your Data Secure? .NET Edition
- 1. SQL Injection Attacks: Is Your Data Secure? Cleveland C#/VB.Net User Group | Bert Wagner | February 22, 2018
- 2. Objective SQL injection prevention does not have an “easy” solution
- 3. Disclaimers • Try this at home • Not at work • Not on other people’s systems
- 4. Background • Business Intelligence Developer • Tech security enthusiast • Saw my first injection attempts in ~2001 – MySQL logs Demo code and slides available at bertwagner.com
- 5. Overview 1. Importance of SQL injection protection 2. Dynamic SQL 3. What does SQL injection look like? 4. Common misconceptions 5. Preventing SQL injection
- 6. • Data Leaks • Data Validity • Server Availability
- 7. Dynamic SQL “Just because you can, doesn’t mean you should.” • Can’t parameterize everything • Adaptable Queries • Performance However…
- 8. What is SQL Injection? • Dynamic string execution • Unsanitized input (could be from a column or parameter) • Performing something the query wasn’t originally intended to do
- 9. What is SQL Injection? Concatenating a parameter into our query string
- 10. What is SQL Injection? SQL injection can occur without concatenated parameters too
- 11. Let’s go back to 1998…
- 12. OWASP 2004
- 13. OWASP – Present Day
- 14. Common Misconceptions “The structure of my database isn’t public” You don’t have a Users table? Products? Inventory? etc... “The Amazing Bert”
- 15. Common Misconceptions “I obfuscate my table names” sys.objects? Errors displayed in app? Logs, emails, social engineering…?
- 16. Common Misconceptions “Isn’t it the DBAs job to protect the database?” True. But multiple layers of security are better than one. Front end validation doesn’t stop malicious users Server side validation does
- 17. Common Misconceptions “I’m not important enough to get hacked” Automated injection tools target everyone https://github.com/sqlmapproject/sqlmap/wiki/Techniques
- 18. Common Misconceptions “I use an ORM to code my SQL queries” ORMs are still vulnerable if you need to pass an argument that can’t be parameterized by SQL Server or if you use a vulnerable stored procedure Other libraries, like the LINQ Dynamic Query Library, try to mitigate this but are also not perfect https://stackoverflow.com/questions/8738953/is-injection-possible-through-dynamic-linq
- 19. Protecting Against SQL Injection Must take a multi-layered approach. Demos: • Don’t write dynamic SQL • sp_executesql • QUOTENAME() • REPLACE() • EXECUTE AS • Limit inputs • Homoglyph attacks • Proactively find injection vulnerabilities
- 20. Other Tools • sqlmap • Azure SQL • Continuous monitoring tools • Troy Hunt’s “hackable” website: https://hackyourselffirst.troyhunt.com/
- 21. Recap • No easy, single-approach solution • Validate, sanitize, escape • Developers and DBAs both responsible • Limit executing account privileges • Use other software to help test, find vulnerabilities
- 22. Thank you! @bertwagner bertwagner.com youtube.com/c/bertwagner bert@bertwagner.com 22 New posts and videos every Tuesday!
Editor's Notes
- #12: Hard to pin point exactly who first discovered SQL injection. DO know that in 1998 already appearing in hacker zines. This examples is showing a SQL query that’s variabalized in some app code
- #13: - Web 2.0, shiny buttons and every company trying to make money online. Problem was, no one knew how to do security. Unless you had a really security conscious developer, you were out of luck. Open Web Application Security Project was formed because a group of people realized needed to create education, information about the types of attacks out there. Put together top 10 list In the initial years, these ranked by guessing/first hand experience – no statistics available SQL and other injection attacks ranked as #6.