As more people gain access to the internet, organizations are increasingly developing web-based applications for user interaction.
However, poorly coded web applications can be a vulnerability, allowing unauthorized access to sensitive information and compromising web servers.
In this tutorial, you will learn how to hack a website and a bit about hacking databases, exploring various web application hacking techniques, and understanding the countermeasures you can implement to safeguard against such attacks.
Key Takeaways
- Familiarize yourself with web application hacking techniques.
- Understand the importance of implementing countermeasures to protect sensitive data.
- Awareness of potential vulnerabilities in web-based applications is crucial for maintaining security.
How to Hack a Website
In this practical scenario, let’s consider hacking the user session of a web application at www.techpanda.org.
The objective is to use cross-site scripting (XSS) to obtain the user’s session ID and impersonate a legitimate user.
The attacker already has access to the application and aims to gain admin access.
1. Start by visiting http://www.techpanda.org.
2. Input the login credentials.
3. Successfully logging in directs you to the dashboard.
4. Head to “Add New Contact” and input the following code as the first name:
5. This code incorporates JavaScript, adding a hyperlink with an onclick event. When a user clicks this link, the event retrieves the PHP session ID and sends it to the snatch_sess_id.php page.
6. Input the remaining details and save changes.
7. Your updated dashboard includes the new contact.
8. As the XSS code is now stored in the database, it loads every time users with access rights log in. Suppose an administrator logs in and clicks on “Dark”; a window with the session ID appearing in the URL is displayed.
Remember, the script could be transferring the value to a remote server where the PHP session ID is stored.
Users can then be redirected back to the website, unaware of the intrusion.
The value you obtain might differ from this example, but the underlying concept remains the same.
In this section, you’ll learn about session impersonation using Firefox and the Tamper Data add-on.
First, make sure you have Firefox installed, and then follow these steps to install the Tamper Data add-on:
1. In Firefox, click on the menu bar on the right end, then select Add-ons.
2. In the search bar field, search for Tamper Data add-on and click on Install.
3. Restart the Firefox Browser after the installation is complete.
Now, let’s see how you can use Tamper Data for session impersonation:
1. If the menu bar isn’t displayed in Firefox, enable it.
2. Click on the Tools menu, then select Tamper Data.
3. A new window will appear. If there is any existing data, click on the Clear button.
4. Click on the Start Tamper menu.
5. Switch back to your Firefox browser and type in the target URL (e.g., http://www.techpanda.org/dashboard.php), then press Enter.
6. A Tamper Data pop-up will appear. Choose the Tamper option, which lets you modify the HTTP header information before submitting it to the server.
7. Another window will appear. Paste the previously obtained PHP session ID (for example, 2DVLTIPP2N8LDBN11B2RA76LM2) after the equal sign.
8. Click the OK button.
9. The Tamper Data pop-up will show up again. Uncheck the checkbox “Continue Tampering?” and click the Submit button.
By following these steps, you’ll be able to access the dashboard without logging in, as you’ve now impersonated a login session using the PHP session ID retrieved through cross-site scripting.
Keep in mind that your goal is to understand this process to protect your own website better, not to misuse it.
Understand Web Applications and Their Threats
A web application is an online platform designed with a client-server model.
It runs on a web browser while the server, hosted on a web server, facilitates access to databases and handles the business logic.
Common programming languages used for web applications include Java, C#, PHP, and ColdFusion Markup Language, while popular database engines are MySQL, MS SQL Server, PostgreSQL, and SQLite.
Due to the public accessibility of most web applications, they are susceptible to various threats.
Here are some common web application threats:
- SQL Injection: Attackers can bypass login algorithms or damage data by exploiting vulnerabilities in the application’s SQL queries.
- Denial of Service Attacks (DoS): By overloading the application’s resources, this attack aims to prevent legitimate users from accessing the platform.
- Cross-Site Scripting (XSS): This threat involves injecting malicious code that can be executed within a user’s web browser, potentially leading to unauthorized access or data theft.
- Cookie/Session Poisoning: Modifying cookie or session data allows attackers to gain unauthorized access to a web application.
- Form Tampering: An attacker may change form data, such as prices in e-commerce applications, enabling them to obtain items at reduced prices.
- Code Injection: Injecting server-executable code like PHP or Python can reveal sensitive information, install backdoors, or compromise the server’s security.
- Defacement: In this type of attack, a hacker alters a website’s appearance or redirects all page requests to a single page showcasing the attacker’s message.
By being aware of these threats, you can take appropriate measures to protect your web applications against cyberattacks.
How to Safeguard Your Website from Hacking Attempts
To protect your website from various web server attacks, consider implementing the following security measures:
- SQL Injection: Reduce the risk of SQL injection by sanitizing and validating user inputs before submitting them to the database. Use prepared statements and parameterized queries when working with database engines like MS SQL Server or MySQL, as they are safer than traditional SQL statements.
- Denial of Service (DoS) Attacks: Utilize firewalls to block traffic from suspicious IP addresses during a DoS attack. Proper network configuration and intrusion detection systems can also help prevent successful attacks.
- Cross-Site Scripting: Minimize XSS attacks by validating and sanitizing headers, URL parameters, form parameters, and hidden values.
- Cookie/Session Poisoning: Encrypt cookie contents, set expiration times, and associate cookies with the client IP address used to create them in order to prevent cookie or session poisoning.
- Form Tampering: Validate and verify user input before processing to avoid form tampering.
- Code Injection: Treat all parameters as data, not executable code, to prevent code injection. Implement sanitization and validation techniques for added security.
- Defacement: Establish a strong web application development security policy to seal common vulnerabilities and safeguard your web server. Proper operating system configuration, web server software settings, and adherence to best security practices during web application development are essential.
By following these recommendations, you can effectively enhance your website’s security and protect it against potential hacking attempts.
Summary
As a user of web applications, it’s important to be aware of the potential threats your applications face.
With accessibility over the internet, these applications are vulnerable to various attacks, such as SQL Injection, Code Injection, XSS, Defacement, and Cookie poisoning.
To protect your web applications, it’s essential to enforce a strong security policy during development, which can safeguard them against these common vulnerabilities.
