$stmt = $pdo->prepare('SELECT coupon_name FROM coupons WHERE user_email = :email'); $stmt->execute(['email' => $userInput]); Use code with caution.
often fail because the application specifically removes or escapes the single quote character ( Bypass Technique backslash (
SQL Injection Challenge 5 in OWASP Security Shepherd is a classic lesson in and authentication bypass . It tests your ability to manipulate database queries when the application doesn't return direct data. 🛡️ Understanding the Challenge
From online discussions and walkthroughs of similar Security Shepherd challenges, a key observation emerges: . The backend query is using double quotes around the user input!. This means the query being executed is actually: Sql Injection Challenge 5 Security Shepherd
If the application returns an error or a message like "Multiple coupons found," you know the input is being executed as part of a SQL query.
This is the best defense. It ensures that user input is always treated as data, never as executable code.
After empirical testing on Security Shepherd v3: This is the best defense
The challenge forces the user to move beyond basic exploitation and think about how the escaping function operates. The backend's goal is to neutralize single quotes to prevent the attacker from breaking out of the SQL query's string context. However, the escaping function is applied recursively or without proper input validation.
The OWASP Security Shepherd SQL Injection Escaping Challenge is a milestone in understanding web application security. It effectively demonstrates that security is about details and that a single oversight—such as an imperfect escaping routine—can lead to catastrophic results.
The only reliable way to prevent SQL injection is to use (also known as prepared statements). This approach separates the SQL logic from the data, ensuring that user input is treated as a literal value rather than as part of the SQL command. The challenge is a stark reminder that relying on escaping or blacklisting is a losing battle. but OR / AND are.
Once the injection is successful, the application will reveal the "key" or flag for that module, indicating that the challenge has been solved.
Observing that -- is not filtered in this challenge, but OR / AND are. We need a tautology without those words.