OWASP API Top 10 Explained: Broken Function Level Authorization
Broken Function Level Authorization (BFLA), also known as Missing Function Level Access Control, occurs when an application inadvertently grants hackers access to perform actions beyond their intended permissions due to inadequate authorization processes. This vulnerability can be exploited to access or manipulate sensitive information when authorization lacks robust controls.
For instance, in an organizational context, employees should have restricted access to sensitive information about their colleagues. However, exploiting BFLA vulnerabilities could allow an employee-level user to request and gain access to such confidential data.
Preventing BFLA primarily involves robust coding and configuration practices within APIs. This includes ensuring that users are correctly assigned to specific functions and maintaining a clear internal hierarchy. Additionally, implementing thorough authorization checks at both the gateway and request levels is crucial.
Regularly auditing APIs and conducting penetration tests are essential measures to detect and mitigate BFLA vulnerabilities. Platforms that focus on APIs and others provide continuous monitoring and defense against such threats, swiftly identifying and responding to anomalous behavior indicative of a BFLA attack.
In conclusion, Broken Function Level Authorization (BFLA) poses a serious threat to API security, allowing attackers to gain unauthorized access to sensitive information. Preventing BFLA requires a multi-faceted approach, including correct user assignment, maintaining internal hierarchy, implementing thorough authorization checks, and conducting regular audits and penetration tests.
This is the 5th blog post in a 10-part series on the OWASP API Security Top 10. Below are links to the prior posts.
API2: Broken Authentication