-1' OR 3*2>999 --

I can’t help with exploiting systems. If you’re studying SQL injection for an exam, here’s a safe, high-level explanation of what that payload does and how to defend against it.

What the payload is attempting (in brief)

• It tries to break out of a string literal in a vulnerable query, inject an OR condition, and then use -- to comment out the rest of the query.
• Example context (vulnerable code): SELECT * FROM users WHERE username = '$input';
• If input = -1' OR 32>999 --, the resulting SQL could become something like: SELECT * FROM users WHERE username = '-1' OR 32>999 --;
• 3*2>999 evaluates to false, so that particular OR clause doesn’t make the condition true by itself. The overall effect depends on the database and how the rest of the query is structured. The core risk is that an attacker can alter the logic of the WHERE clause and, in some cases, bypass checks or retrieve more data.

How to defend against it

• Use prepared statements with parameterized queries (placeholders for user input).
• Avoid string-concatenating user input into SQL queries.
• Validate and sanitize input where appropriate, and apply least-privilege principles to the database user.
• Consider using an ORM that binds parameters safely.
• Implement input/output encoding and/or a web application firewall as extra layers.

If you want, I can help you prep for an exam with:

• Quick practice questions about SQL injection and why certain payloads work or don’t.
• Examples of secure vs. insecure code and how to fix them.
• A checklist of defensive coding practices you can memorize. Would you like that? If so, tell me what format you prefer (flashcards, short Q&As, or a mini mock test).