Broken Access Control

Overview

Access controls are critical for securing applications against unauthorized access to data and resources. Broken access controls can lead to data compromise, obtaining permissions beyond what’s intended for standard users, or account takeover attacks where outsiders hijack user accounts and initiate fraudulent transactions.

Description

Broken Access Control vulnerability refers to the improper implementation of access controls in web applications. This allows unauthorized users to access sensitive data and perform actions that they should not be able to. This vulnerability has become increasingly common, with 94% of tested applications found to have this vulnerability. Common vulnerabilities in this risk category include application logic faults that bypass access control checks by allowing users to change parameter values or force browse to certain URLs. To prevent this vulnerability, it is crucial to emphasize the importance of shifting security left in the development cycle. Access controls should be implemented early on in web app development, denying requests by default and rate limiting APIs.

How to Prevent ?

To prevent Broken Access Control vulnerability, follow these best practices: 1. Implement proper access controls throughout the application. 2. Deny requests by default and explicitly allow only what is necessary. 3. Use role-based access controls (RBAC) to assign access privileges based on user roles. 4. Regularly review and update access control configurations to ensure they are still effective. 5. Implement rate limiting to prevent abuse or automated attacks. 6. Perform thorough security testing to identify and address any access control vulnerabilities. 7. Train developers and educate them about secure coding practices and the importance of access controls.

Example Attack Scenarios:

• Account Takeover:  An attacker exploits a broken access control vulnerability to gain unauthorized access to a user's account. They may do this by bypassing authentication mechanisms or manipulating access control mechanisms. Once they have gained access to the account, they can perform actions on behalf of the user, such as making unauthorized purchases or accessing sensitive information.

• Privilege Escalation:  In a system with broken access control, an attacker may exploit vulnerabilities to gain elevated privileges. They may start with a low-privileged account and escalate their privileges to gain access to restricted resources or perform actions that should only be allowed for privileged users. This can lead to unauthorized access to sensitive data or unauthorized modification of system settings.