Bug Hunter's Guide to Broken Access Control in Web Applications

As a bug hunter, you are tasked with finding vulnerabilities in web applications before they can be exploited by malicious actors. One of the most common vulnerabilities that you may encounter is broken access control. In this post, we will discuss what broken access control is, why it is important, and how to identify and exploit this vulnerability.

What is Broken Access Control?

Access control is the process of ensuring that only authorized users can access specific resources within a web application. Broken access control occurs when this process fails, allowing unauthorized users to access restricted resources. This can happen due to various reasons such as improper implementation of access control rules, lack of proper authentication and authorization mechanisms, or lack of input validation.

Why is Broken Access Control Important?

Broken access control is a serious vulnerability that can result in unauthorized access to sensitive data, user accounts, and system resources. This can lead to a range of security threats, including data theft, identity theft, and system compromise. As a bug hunter, it is important to identify and report this vulnerability to help ensure that web applications remain secure.

How to Identify Broken Access Control

Identifying broken access control requires a deep understanding of how the web application works, including the authentication and authorization mechanisms in place. Here are some common signs of broken access control that bug hunters should look for:

• Inconsistent access control rules across the application
• Access to sensitive resources without proper authentication
• Direct object reference (DOR) vulnerabilities
• Lack of input validation leading to parameter manipulation
• Insufficient session management

How to Exploit Broken Access Control

Once you have identified a broken access control vulnerability, the next step is to attempt to exploit it. Exploiting this vulnerability requires some technical skills and knowledge of web application security. Here are some steps that can be taken to exploit this vulnerability:

• Identify the vulnerable resource and the access control mechanism in place
• Bypass the access control mechanism using techniques such as URL manipulation, session hijacking, or parameter tampering
• Gain unauthorized access to the restricted resource
• Collect data or perform actions that were not authorized

How to Prevent Broken Access Control

Preventing broken access control requires a combination of technical and non-technical controls. Here are some best practices that can help prevent this vulnerability:

• Implement proper authentication and authorization mechanisms
• Use a role-based access control (RBAC) model
• Validate user input to prevent parameter manipulation attacks
• Use secure session management techniques
• Conduct regular security audits to identify and remediate vulnerabilities

Conclusion

Broken access control is a serious vulnerability that can result in unauthorized access to sensitive resources within a web application. As a bug hunter, it is important to understand this vulnerability, its impact, and how to identify and exploit it. By following best practices to prevent this vulnerability, web applications can remain secure and protected from potential attacks.