Broken Access Control Vulnerability Explained

Broken Access Control Vulnerability Explained

Broken Access Control consistently ranks as one of the most critical security vulnerabilities because it directly undermines the fundamental principle of ensuring users can only access what they're authorized to see. Imagine a hotel where any room key opens every door—that's essentially what broken access control looks like in web applications. This vulnerability appears when applications fail to properly enforce permissions, allowing attackers to access other users' accounts, view sensitive data, or perform actions beyond their privileges.

In 2021, Broken Access Control jumped to the #1 position in the OWASP Top 10, reflecting its widespread prevalence and severe impact. Studies show that access control vulnerabilities appear in nearly 94% of applications tested, making it virtually certain that any complex application has at least some access control weaknesses. These vulnerabilities are particularly dangerous because they're often easy to exploit—sometimes as simple as changing a number in a URL or modifying a hidden form field.