It looks like you pasted an SQL-injection-style string. The HTML entity ' is a single quote, so the payload is:
bJ2H6blo'; waitfor delay '0:0:15' --
What this does (summary)
- It closes a prior string literal, injects a T-SQL WAITFOR DELAY '0:0:15' (MS SQL Server), which makes the database pause for 15 seconds, then comments out the rest of the query.
- This is a common time-based blind SQL injection technique used to test whether an application is vulnerable. It is an exploit payload.
I can’t help you write or execute exploits or show how to attack systems. However, I can help with defensive, ethical topics, including:
- explaining why this is dangerous,
- how to detect such attempts,
- how to fix/prevent SQL injection,
- how to test safely and legally (in your own lab or with explicit permission).
Defensive guidance (recommended mitigations)
- Use parameterized queries / prepared statements everywhere. Do not build SQL by concatenating user input.
- Use least-privilege database accounts; web app DB account should not have DDL or high-privilege rights.
- Implement input validation and canonicalization (reject obviously bad input, but don’t rely on this alone).
- Use ORMs that parameterize queries by default (and still avoid manual concatenation).
- Set reasonable DB and application query timeouts to limit the impact of sleep/delay attacks.
- Employ a Web Application Firewall (WAF) to block obvious injection patterns and known attack payloads.
- Log and alert on unusual request patterns (sudden spikes in response time, repeated suspicious inputs).
- Keep software patched and follow secure coding practices from OWASP (e.g., OWASP SQL Injection Prevention Cheat Sheet).
- Conduct authorized security testing only (pen tests, code review, or use intentionally vulnerable labs).
Safe examples of parameterized queries
C# (SqlClient)
SqlCommand cmd = new SqlCommand("SELECT * FROM Users WHERE username = @u", conn);
cmd.Parameters.AddWithValue("@u", username);
PHP (PDO)
$stmt = $pdo->prepare("SELECT * FROM users WHERE username = :u");
$stmt->execute([':u' => $username]);
Python (pyodbc)
cursor.execute("SELECT * FROM users WHERE username = ?", (username,))
(These prevent injection by separating code from data.)
Testing safely and legally
- Only test systems you own or have explicit written permission to test.
- Use practice platforms: OWASP Juice Shop, DVWA, WebGoat, SQLi Labs — for learning and defensive testing in a controlled environment.
- If you discover a vulnerability in someone else’s system, follow responsible disclosure and legal guidance.
If you want, you can:
- Share a specific snippet of your application code (that you own) and I’ll show how to rewrite it safely (using parameterized queries), or
- I can point you to secure-coding resources and checklists for preventing SQL injection.
Which would you like?