> For the complete documentation index, see [llms.txt](https://alham-rizvi.gitbook.io/alhamrizvi/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://alham-rizvi.gitbook.io/alhamrizvi/picoctf-writeups/picoctf/web-exploitation/web-gauntlet-3.md).

# web-gauntlet-3

Log in as the **admin** user to retrieve the flag. However, there are two major obstacles:

* **A Blacklist:** Words like `admin`, `or`, `and`, `=`, and `true` are forbidden.
* **Character Limit:** Your total input cannot exceed **25 characters**.

The login page uses a **SQLite** database. When you enter data, the server reflects the query it is trying to run.

> **Reflected Query:** `SELECT username, password FROM users WHERE username="..." AND password="..."`

#### **3. The Bypass Strategy**

**Step A: Bypassing the "admin" Filter**

Since we cannot type `admin`, we use **String Concatenation**. In SQLite, the `||` operator joins two strings together.

* **Payload:** `'ad'||'min'`
* **Result:** The database combines them into `admin`, but the security filter only sees `ad` and `min`, so it lets it pass.

**Step B: Bypassing the "=" Filter**

We need to make the password check "True" without using the `=` sign. We use the **`GLOB`** operator with a wildcard.

* **Payload:** `GLOB '*'`
* **Result:** `GLOB` matches patterns. The asterisk (`*`) matches **anything**. This makes the password check always true because any password stored in the database will match "anything".

#### **4. Final Execution**

To stay under the 25-character limit, enter these into the login fields:

* **Username:** `ad'||'min`
* **Password:** `'GLOB'*`

#### **5. Capturing the Flag**

Once you are logged in as admin, the challenge description states the flag will be located at:

> `http://wily-courier.picoctf.net:59492/filter.php`


---

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