Understanding Broken Access Control (BAC): A Comprehensive Guide

As web applications have evolved from static to dynamic, the complexity of managing access has grown. The need for stringent access control mechanisms has become paramount, especially as data sensitivity and security concerns rise. Enter Broken Access Control (BAC) — a prevalent vulnerability in web applications that poses significant security risks. BAC can lead to unauthorized access to resources, enabling attackers to escalate privileges, manipulate data, and breach user privacy.

In this article, we’ll explore what BAC is, the various forms it can take, common attack strategies, and practical ways to test for and mitigate this vulnerability. By the end, you’ll understand how BAC works, how to recognize it, and the tools and techniques you can use to defend against it.

Broken Access Control is, quite simply, a failure in enforcing restrictions on what authenticated users are allowed to do. It manifests primarily in two types of privilege escalation: