SQL Injection Challenge 5 in OWASP Security Shepherd is a classic lesson in blind injection and authentication bypass. It tests your ability to manipulate database queries when the application doesn't return direct data. 🛡️ Understanding the Challenge
In Challenge 5, you are typically presented with a login screen or a search bar. Unlike earlier levels where you might see database errors or dumped tables, this level is "quieter."
The Goal: Gain unauthorized access or retrieve the hidden "key."
The Vulnerability: The application takes user input and places it directly into a SQL string without sanitization. 🔍 Step-by-Step Walkthrough 1. Identify the Entry Point
Locate the input field. Start by entering a single quote (').
If the page breaks or behaves differently, it confirms the input isn't being escaped.
In Challenge 5, a successful injection often results in a "Welcome" message or a successful login redirect. 2. The Logic Bypass
The query behind the scenes likely looks like this:SELECT * FROM users WHERE username = '$user' AND password = '$pass'
To bypass this, you need to make the WHERE clause always evaluate to TRUE. Enter this into the username field:admin' OR '1'='1 3. Handling the Password Sql Injection Challenge 5 Security Shepherd
Since the password check follows the username, you need to "comment out" the rest of the query so the system ignores the password requirement. For MySQL/PostgreSQL: admin' OR '1'='1' # For MS SQL: admin' OR '1'='1' -- 4. Refining the Payload
If the simple bypass doesn't work, the application might be checking for a specific number of columns or a specific user ID. Try:' OR 1=1 LIMIT 1 --
This tells the database: "Give me the first record in the table where the condition is true." Since '1=1' is always true, it logs you in as the first user (usually the Admin). 💡 Key Takeaways for Security Shepherd
Case Sensitivity: Sometimes the keyword OR must be uppercase or lowercase depending on the filter.
URL Encoding: If you are submitting via a URL bar, remember that spaces should be %20 and hashes should be %23.
Observation: Pay attention to the URL or the session tokens after a "successful" login; the key is often hidden there. 🚫 How to Prevent This To stop SQL injection in real-world apps:
Prepared Statements: Use parameterized queries so input is never treated as code.
Input Validation: Use allow-lists to ensure only expected characters are submitted. SQL Injection Challenge 5 in OWASP Security Shepherd
Principle of Least Privilege: Ensure the database user has limited permissions.
To help you get through this specific level, could you tell me: What response do you get when you submit a single quote? Are you seeing a login box or a search field?
Why does this contrived challenge matter? Because real-world SQL injection often looks exactly like this.
Doing this manually for 32 characters is intellectually satisfying but practically insane. The intended solution for Challenge 5 is a script. Below is a Python example using requests to automate Boolean blind SQL injection.
If the true/false response is identical, fall back to time-based:
5' AND IF(ASCII(SUBSTRING((SELECT hash FROM keys LIMIT 1),1,1)) = 97, SLEEP(5), 0) AND '1'='1
Then measure response time (>5 seconds = true).
We cannot steal the flag if we don't know the table name. We need to query the metadata. In Security Shepherd, the underlying database is typically MySQL (or sometimes H2). The metadata is stored in information_schema.
We want to find the table names. We suspect the data is in the second column. Step 4: Enumerate the Database Schema We cannot
Payload:
' UNION SELECT 1, table_name, 3 FROM information_schema.tables--
Result Analysis:
The application will likely list the first table name it finds in the database (e.g., CHARSETS or COLLATIONS). However, we want the application-specific tables. We need to narrow this down.
Typically, the default database schema name in Shepherd is PUBLIC or sometimes just the default schema.
Payload to find tables in the current schema:
' UNION SELECT 1, table_name, 3 FROM information_schema.tables WHERE table_schema != 'mysql' AND table_schema != 'information_schema'--
Note: The exact exclusion list may vary, but usually, you are looking for tables that look like users, challenge, or specifically tbl_ch5.
Let's assume the output reveals a table named challenge5 (or similar).
In Challenge 5, you are usually presented with a simple user interface containing an input field—often a search bar or a user ID lookup. When you input valid data, the application returns specific details (like a username or email). However, the goal is not just to log in; it is to retrieve hidden data (specifically, the "Admin" password or a specific flag) that is not intended to be visible.
The key difference in this challenge is often the lack of verbose SQL error messages. Unlike the "Low" or "Medium" challenges where syntax errors might reveal the database structure, Challenge 5 often implements a "Silent" error handling mechanism. If your SQL syntax is wrong, the page simply returns nothing or a generic error, rather than a database stack trace.