How to Learn SQL Injection for CEH Exam?

Introduction

SQL Injection remains one of the most critical and frequently tested vulnerabilities in the CEH exam and real-world penetration tests. Even in 2025-2026, SQLi consistently ranks in the OWASP Top 10 because countless websites still store data insecurely.

Mastering SQL Injection not only helps you score easy marks in the CEH theory and practical exam but also makes you extremely valuable to employers who need web application penetration testers.

Understanding How SQL Injection Actually Works

At its core, SQL injection happens when user input is incorrectly filtered and gets concatenated directly into a database query.

• Normal query: SELECT * FROM users WHERE username = 'admin' AND password = 'pass123'
• Malicious input: ' OR '1'='1' --
• Final query becomes: SELECT * FROM users WHERE username = '' OR '1'='1' --' AND password = ''

This simple trick can bypass login forms, dump entire databases, or even gain shell access.

Different Types of SQL Injection You Must Master for CEH

• Error-based SQL Injection
• Union-based SQL Injection
• Blind Boolean-based SQL Injection
• Time-based SQL Injection
• Out-of-band (OOB) SQL Injection
• Stacked Queries / Multiple Statements

CEH v13 exam expects you to identify and exploit at least the first four types confidently.

Start practicing error-based and union-based attacks today.

Step-by-Step Manual SQL Injection Process

• Find input fields (login forms, search boxes, URL parameters)
• Test with single quote (') to trigger error
• Determine number of columns using ORDER BY
• Find visible columns using UNION SELECT
• Extract database name, table names, column names
• Dump usernames, passwords, and sensitive data

Essential Tools Every CEH Student Uses for SQL Injection

Master labs for unlimited practice.

Best Practice Labs to Master SQL Injection (Free & Legal)

• DVWA (Damn Vulnerable Web Application)
• SQLi Labs
• PortSwigger Web Security Academy (SQL injection section)
• bWAPP
• WebGoat
• Mutillidae II
• TryHackMe SQL Injection room
• Hack The Box starting point challenges

Advanced Techniques: Blind and Time-Based SQL Injection

When nothing is displayed on screen, attackers use blind techniques.

• Boolean-based: Asking true/false questions using AND 1=1, AND 1=2
• Time-based: Using WAITFOR DELAY '0:0:10' or SLEEP(10)
• Extracting data character by character using SUBSTRING and ASCII

These are heavily tested in CEH Practical and real pentests.

Blind SQLi requires patience – perfect your lab first.

Bypassing Filters and WAFs (Exam Favorite)

• Case variation: UnIoN SeLeCt
• Double encoding and comments: %55%4e%49%4f%4e/**/SeLeCt
• Using HPP (HTTP Parameter Pollution)
• Tamper scripts in Burp and sqlmap

Prevention Techniques Every Ethical Hacker Must Know

• Use prepared statements and parameterized queries
• Implement stored procedures properly
• Apply input validation and sanitization
• Use ORM frameworks (Hibernate, Django ORM)
• Deploy Web Application Firewall (ModSecurity, Cloudflare)
• Principle of least privilege for database users

Understanding prevention is equally important for the exam.

SQL Injection Cheat Sheet for Quick Revision

• Basic test: ' OR '1'='1
• Find columns: ' ORDER BY 10--
• Union attack: ' UNION SELECT 1,2,3,4--
• Database name: ' UNION SELECT 1,database(),3,4--
• Table names: ' UNION SELECT 1,table_name,3,4 FROM information_schema.tables--
• Time delay: ' AND IF(1=1, SLEEP(5),0)--

Conclusion

SQL Injection is not just another checkbox in the CEH syllabus — it is one of the highest-scoring and most practical modules. Follow this exact path:

• Week 1–2: Manual error-based & union-based on DVWA Low/Medium
• Week 3: Master blind and time-based on PortSwigger labs
• Week 4: Automate with sqlmap and bypass WAFs
• Practice daily for 30–60 minutes

Once you can reliably extract data from any vulnerable app under 10 minutes, you are 100% ready for both the CEH exam and real job interviews.

Start your hands-on journey today with proper guidance and unlimited lab access.

Frequently Asked Questions

Is SQL injection still relevant in 2025?

Yes. Thousands of websites and APIs are still vulnerable. It remains in OWASP Top 10 every year.

Will I get SQL injection questions in CEH exam?

Almost guaranteed. Both theory and practical exams include multiple SQLi scenarios.

Which type of SQLi is most common in CEH Practical?

Error-based and union-based appear most frequently.

How long does it take to learn SQL injection properly?

With daily practice, most students become confident in 3–4 weeks.

Is sqlmap enough for CEH exam?

No. You must know manual exploitation first. sqlmap is only for automation.

Can I practice SQL injection without installing anything?

Yes. Use PortSwigger Web Academy — completely browser-based and free.

Do I need to learn MySQL, MSSQL, Oracle syntax?

Focus 90% on MySQL syntax — it covers 95% of exam and real-world scenarios.

Is blind SQL injection hard?

It feels slow at first, but once you understand the logic, it becomes mechanical.

How many marks does SQL injection carry in CEH?

Typically 15–25 marks combined in theory and practical.

Which is the best free lab for SQLi?

PortSwigger Web Security Academy SQL injection labs are world-class and completely free.

Should I learn NoSQL injection too?

Not required for CEH, but good for advanced certifications like OSCP.

Can SQL injection give shell access?

Yes, using INTO OUTFILE or xp_cmdshell in privileged cases.

Is SQL injection only for login bypass?

No. You can extract full databases, modify data, or even execute OS commands.

Do modern frameworks prevent SQLi automatically?

Most modern frameworks do when used correctly, but legacy apps and poor coding still make SQLi common.

How do I start today?

Install DVWA or open PortSwigger labs and start breaking things legally right now.