Attack Authorization Schemes

Attack Authorization Schemes

Understanding Attack Authorization Schemes

Authorization schemes are critical security mechanisms that determine what actions users can perform after they have been authenticated. Attacking these schemes is a significant threat vector that ethical hackers and security professionals must understand.

Why Understanding Authorization Attacks is Important

Authorization attacks can allow attackers to:
- Access restricted functionality and resources
- Escalate privileges beyond their assigned level
- Bypass security controls intended to limit user actions
- Perform actions as other users, including administrators
- Extract sensitive data from systems

In security certifications like CEH, understanding these attack vectors is essential for both defending against them and demonstrating technical security knowledge.

Common Authorization Attack Techniques

1. Insecure Direct Object References (IDOR)
This occurs when applications expose internal implementation objects to users. For example, changing a parameter in a URL from account?id=123 to account?id=124 to access another user's account.

2. Horizontal Privilege Escalation
Accessing resources of another user with the same privilege level.

3. Vertical Privilege Escalation
Gaining access to functions reserved for higher-privilege users.

4. Parameter Tampering
Modifying parameters sent to the server to manipulate authorization checks.

5. Forced Browsing
Attempting to access restricted URLs by guessing their existence.

6. Path Traversal
Using "../" sequences to access files outside the web root directory.

7. JWT Attacks
Manipulating JSON Web Tokens to bypass authorization.

Authorization Vulnerabilities to Know

- Missing Function Level Access Control: When applications fail to verify authorization on the server side for each function.

- Client-Side Authorization: When authorization is implemented only on the client side and can be bypassed.

- Improper Session Management: When the application doesn't properly maintain and validate session states.

- Insecure Role/Permission Management: When roles and permissions are not properly defined or enforced.

Tools Used for Authorization Attacks

- Burp Suite (Proxy and Authorization add-ons)
- OWASP ZAP
- Browser developer tools
- Custom scripts for token manipulation
- JWT debugging tools (e.g., jwt.io)

Exam Tips: Answering Questions on Attack Authorization Schemes

1. Understand the Difference Between Authentication and Authorization
Authentication verifies identity (who you are), while authorization determines what you can do.

2. Know Authorization Mechanisms
Be familiar with Role-Based Access Control (RBAC), Attribute-Based Access Control (ABAC), Mandatory Access Control (MAC), and Discretionary Access Control (DAC).

3. Recognize Attack Patterns
Questions often describe scenarios - recognize which authorization attack is being described.

4. Focus on Business Logic
Many authorization flaws relate to business logic errors. Pay attention to questions about workflow bypass or accessing restricted functions.

5. Understand Defense Mechanisms
Know how to implement proper authorization controls, such as:
- Server-side validation of access rights
- Principle of least privilege
- Regular permission reviews
- Control of session management

6. Read Multiple Choice Options Carefully
For multiple choice questions, look for key terms related to authorization attacks. Eliminate options that relate to other attack types.

7. Context Matters
The appropriate authorization model depends on the context. Select answers that match the scenario described.

8. Common Exam Scenarios
Be prepared for questions on:
- Scenarios where an ordinary user accesses admin functions
- URL manipulation to access unauthorized resources
- Business logic flaws that allow bypassing purchase processes
- API authorization bypass techniques

Understanding authorization attacks requires thinking about applications from both a developer and attacker perspective. Consider what checks might be missing and how an attacker could circumvent authorization mechanisms.