As cybersecurity becomes an increasingly critical concern across industries globally, it is paramount to recognize the inherent dangers within our networks, systems, and software. One such danger is 'broken access control', a vulnerability that, if exploited, can lead to compromising sensitive data, impacting business operations, and even undermining user trust. This article aims to provide an in-depth exploration of this common but often overlooked security flaw.

Understanding Broken Access Control

Broken access control arises when a user can perform actions that they should not be permitted to, or access data they should not have access to. This ranges from viewing sensitive information, editing other user's data, to taking control of administrative functions. The access control mechanisms implemented to restrict these actions are, in these situations, either absent, insufficient, or misconfigured — the access control is essentially 'broken.'

Common Forms of Broken Access Control

Broken access control can manifest in multiple ways within software applications. Some of the most common forms include Insecure Direct Object References (IDOR), Missing Function Level Access Control, and Forced Browsing.

Insecure Direct Object References (IDOR) occur when an application exposes a reference to an internal implementation object. An attacker can manipulate these references to gain unauthorized access to other objects.

Missing Function Level Access Control often occurs when an application does not consistently perform authorization checks before allowing access to functionality. An attacker may be able to execute functions that should be out of their purview.

Forced Browsing is a technique employed by attackers, through which they attempt to access resources by manually inputting URLs or changing URL parameters. If an application lacks effective access control, this method can lead to unauthorized access to restricted pages.

Detecting Broken Access Control

Detecting broken access control can be challenging as it involves thorough testing that involves both manual and automated methods. These may include User-Role Matrix Testing, Automated Scans, and Penetration testing.

User-Role Matrix Testing: By creating a matrix that delineates what actions each user role (e.g., customer, end user, administrator, etc.) can and cannot perform, you can manually test to ensure the access restrictions are functioning effectively.

Automated Scans: Various automated tools available in the market can simulate attacks to identify potential authorization vulnerabilities. However, while these tools can help identify low-hanging fruits, they may also produce false positives or negatives.

Penetration Testing: Having skilled penetration testers attempt to bypass your access controls can help detect potential security vulnerabilities, including weaknesses related to broken access control.

Preventing Broken Access Control

There are many vital measures that teams can implement to prevent broken access control in their applications. These include Enforcing Default Denial, Principle of Least Privilege, and Regular Access Audits.

Enforcing Default Denial: All access requests should be denied by default unless explicitly granted. Only approve privileges that are necessary for each role.

Principle of Least Privilege: User accounts, systems, and applications should have the fewest privileges necessary to perform their tasks. Reducing the access level reduces the risk of exploitation if that account or application is compromised.

Regular Access Audits: Regularly review and audit accounts and their access levels. Not only to confirm that the correct restrictions are in place, but to also ensure unnecessary access is revoked.

In Conclusion

In conclusion, broken access control is a critical issue in cybersecurity that requires adequate attention and systematic measures to prevent. An understanding of this vulnerability and its various forms, coupled with effective methodologies for detection and prevention, can empower teams to develop more secure software. Remember, staying vigilant and proactive is key to mitigating this risk and ensuring the security of your applications.