# 🔐 Password Reuse & Default Passwords

### 🧠 Common Practices & Risks

* It's common for **users and administrators** to leave **default credentials** unchanged.
* Admins often reuse the **same passwords** across multiple systems for convenience.
* In large infrastructures, it’s easy to **overlook one device** (e.g., router, printer, firewall), leaving it with a weak or default password.
* Applications often ship with **default credentials**. These are:
  * Meant to be changed after installation
  * Often left unchanged due to assumptions about internal-only access

> ⚠️ Using weak or reused passwords increases the **risk of compromise**, especially when **Single Sign-On (SSO)** is not configured during initial setup.

***

## 🤖 Credential Stuffing

### 📄 What Is It?

**Credential Stuffing** is an attack method where default or known credentials are used across various services to gain unauthorized access.

* Relies on databases of **default or leaked credentials**
* Unlike brute-force attacks, it **uses predefined username:password combinations**

🔗 Helpful Resource: [DefaultCreds-Cheat-Sheet](https://github.com/ihebski/DefaultCreds-cheat-sheet)

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### 📋 Example Default Credentials

| Product/Vendor       | Username                   | Password                         |
| -------------------- | -------------------------- | -------------------------------- |
| Zyxel (ssh)          | `zyfwp`                    | `PrOw!aN_fXp`                    |
| APC UPS (web)        | `apc`                      | `apc`                            |
| Weblogic (web)       | `system`                   | `manager`                        |
| Weblogic (web)       | `weblogic`                 | `weblogic1`, `welcome(1)`        |
| Kanboard (web)       | `admin`                    | `admin`                          |
| Vectr (web)          | `admin`                    | `11_ThisIsTheFirstPassword_11`   |
| Caldera (web)        | `admin`                    | `admin`                          |
| Dlink (web)          | `admin`, `1234`, `root`    | `admin`, `1234`, `12345`, `root` |
| JioFiber / GigaFiber | `admin`                    | `jiocentrum`                     |
| Kali Linux (OS)      | `kali`                     | `kali`                           |
| F5                   | `admin`, `root`, `support` | `admin`, `default`, *(blank)*    |

> ℹ️ These can often be found in the [official documentation](https://docs.oracle.com/middleware/1212/wls/INTRO/overview.htm) or using **OSINT**.

***

### 🛠️ Hydra: Credential Stuffing Syntax

Hydra is a powerful tool to automate credential stuffing attacks.

```bash
hydra -C <user_pass.list> <protocol>://<IP>
```

#### Example (SSH attack):

```bash
hydra -C user_pass.list ssh://10.129.42.197
```

***

## 🧭 OSINT & Google Dorks

Using **Open Source Intelligence (OSINT)** can guide attackers in:

* Understanding the **company structure and tools**
* Searching for known credentials (e.g., using Google)

🔍 Example Google Dork:

```plaintext
default credentials for tomcat manager
```

***

## 🌐 Router Default Credentials

Even though routers are often better protected, internal or test systems may still have **default settings**.

#### 📶 Example Router Defaults

| Brand   | IP Address                                    | Username | Password       |
| ------- | --------------------------------------------- | -------- | -------------- |
| 3Com    | [http://192.168.1.1](http://192.168.1.1/)     | `admin`  | `Admin`        |
| Belkin  | [http://192.168.2.1](http://192.168.2.1/)     | `admin`  | `admin`        |
| BenQ    | [http://192.168.1.1](http://192.168.1.1/)     | `admin`  | `Admin`        |
| D-Link  | [http://192.168.0.1](http://192.168.0.1/)     | `admin`  | `Admin`        |
| Digicom | [http://192.168.1.254](http://192.168.1.254/) | `admin`  | `Michelangelo` |
| Linksys | [http://192.168.1.1](http://192.168.1.1/)     | `admin`  | `Admin`        |
| Netgear | [http://192.168.0.1](http://192.168.0.1/)     | `admin`  | `password`     |

📌 Resource: [Router Passwords Database](https://www.routerpasswords.com/)

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