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The Hidden Threat: Mitigating Broken Function-Level Authorization for Strong Application Security

June 22, 2023
Written by
Vishnu Prasad K

Function-level authorization determines who gets access to what within an application. It's all about granting the right privileges to the right people that ensure a tight grip on sensitive functionalities. But here's the catch: Even the most seemingly impenetrable security architectures can harbor hidden flaws.

Broken function-level authorization refers to those pesky vulnerabilities that slip through the cracks. They lurk beneath the surface, ready to be exploited by cunning hackers who know just where to look. These security gaps pave the way for unauthorized access, privilege escalation, and all sorts of digital nightmares that can tarnish your app's reputation and put your users' data at risk.

Table of Contents

  1. What is Broken Function-Level Authorization?
  2. Common Vulnerabilities and Risks Associated with Broken Function-Level Authorization
  3. Exploring Concrete Examples of Broken Function-Level Authorization and Their Implications for Application Security
  4. Effective Mitigation Strategies to Counter Broken Function-Level Authorization
  5. Protect Your Application from Broken Function-Level Authorization with AppSecEngineer

What is Broken Function-Level Authorization?

Broken function-level authorization is a technical vulnerability that arises when an application's access controls fail to properly enforce granular permissions at the functional level. It occurs when flaws in the implementation or configuration allow unauthorized users to access functionalities or resources they shouldn't have access to. This vulnerability can stem from issues such as faulty access control logic, inadequate validation of user permissions, or misconfigured security policies.

Common Vulnerabilities and Risks Associated with Broken Function-Level Authorization

Insufficient or Weak Access Controls

This happens when access controls in an application are not adequately implemented or are easily bypassed because the application doesn't properly enforce restrictions on who can access specific functionalities or resources. Attackers can exploit this weakness by finding loopholes or taking advantage of flaws in the access control mechanisms. They may gain unauthorized access to sensitive data, manipulate functionalities, or perform actions that they shouldn't be able to.

Insecure Direct Object References

When an application exposes direct references or identifiers to internal objects, such as database records or files, without the necessary validation or authorization checks, it is known as an insecure direct object reference. Attackers can use these references to get unauthorized access to confidential information. For instance, if a program uses sequential IDs for records, an attacker can easily access the information of another user by changing the ID in the URL. This is similar to leaving your personal papers laying around where everyone may view them.

Privilege Escalation

Privilege escalation happens when an attacker gains elevated privileges or access rights within an application or system. It can occur in different ways, such as exploiting vulnerabilities, misconfigurations, or programming errors. By escalating their privileges, attackers can perform actions beyond their intended level of access. For instance, they may gain administrative rights, manipulate critical settings, or access sensitive data belonging to other users.

Exploring Concrete Examples of Broken Function-Level Authorization and Their Implications for Application Security

Case Study 1: Vulnerability in an e-Commerce application

In 2013, the retail giant Target encountered a significant data breach that impacted millions of customers. Unfortunately, attackers managed to gain unauthorized access to Target's network by exploiting a vulnerability in a third-party HVAC contractor's system. Once the attackers were inside, they navigated through the network, ultimately reaching the point-of-sale (POS) systems. By discovering and exploiting this vulnerability, the attackers were able to access a customer database and install malware on the point-of-sale systems. This allowed them to collect credit and debit card data, as well as personal information, from millions of Target customers during the busiest shopping season of the year.

Case Study 2: Authorization flaw in a banking system

During the 2016 Bangladesh Bank heist incident, cybercriminals took advantage of vulnerabilities in the authorization process of the bank's SWIFT (Society for Worldwide Interbank Financial Telecommunication) system. The attackers managed to infiltrate the bank's infrastructure and utilized malware to manipulate the authorization process. They specifically exploited weak controls surrounding transaction verification and approval, which allowed them to bypass the inadequate authorization measures in place. Through their actions, the attackers initiated a series of fraudulent transactions, amounting to hundreds of millions of dollars.

Case Study 3: Misconfigured access controls in a healthcare application

In the 2014 Community Health Systems (CHS) data breach incident, there were unfortunate vulnerabilities in the access controls of CHS's systems that allowed attackers to compromise sensitive patient data. During this incident, attackers exploited a misconfigured access control mechanism, enabling them to gain unauthorized access to CHS's network. Despite this setback, CHS responded swiftly to rectify the issue and prevent further breaches. The attackers, upon gaining entry into the system, accessed a range of patient data, including names, addresses, social security numbers, and medical records. While this breach was concerning, it prompted CHS to implement robust security measures and reinforce its commitment to safeguarding patient information.

Effective Mitigation Strategies to Counter Broken Function-Level Authorization

  1. Properly Defining and Implementing Access Controls - Having a well-defined and properly implemented access control framework is essential for maintaining a secure system. This involves identifying and categorizing user roles and responsibilities within the application and mapping them to specific permissions and functionalities. By following the principle of least privilege, organizations can ensure that users are granted only the necessary access for their tasks, preventing unauthorized access to sensitive functions and data. This proactive approach not only enhances security but also reduces the potential impact of any function-level authorization issues.
  1. Regularly Reviewing and Updating Access Control Policies - Policies for access control shouldn't be seen as a one-time setting. To handle new threats and evolving company needs, they must be examined and modified frequently. Organizations should conduct periodic assessments of their access control policies to identify any gaps or vulnerabilities. This involves reviewing user roles, permissions, and associated access controls, as well as evaluating the effectiveness of the implemented controls. By staying proactive and ensuring that access control policies are up to date, organizations can address potential weaknesses and strengthen their defense against broken function-level authorization.
  1. Conducting Penetration Testing and Security Audits - Penetration testing and security audits play a vital role in ensuring the robustness of access controls and enhancing application security. These activities offer proactive measures to assess vulnerabilities and identify weaknesses in the function-level authorization. During penetration testing, real-world attack simulations are performed to uncover potential areas of exploitation. Regular security audits provide a comprehensive evaluation of an organization's compliance with security standards. These audits assess the implementation of access controls, ensuring that policies and procedures are being correctly followed.
  1. Implementing Monitoring and Logging Mechanisms - Implementing strong monitoring and logging mechanisms is essential for maintaining a secure environment and effectively responding to incidents related to broken function-level authorization. Actively monitoring user activities help organizations quickly detect any suspicious behavior, unauthorized access attempts, or unusual usage patterns that may indicate a breach. This proactive approach enables organizations to take immediate action to prevent further damage and protect their systems. Logging mechanisms also play a crucial role in capturing detailed records of user actions. These records serve as valuable evidence for forensic analysis and investigations in case of security incidents. By analyzing these logs, organizations can identify potential weaknesses in their access controls, further enhancing their security measures. Additionally, logging facilitates compliance auditing by enabling the tracking and review of user actions, ensuring regulatory requirements are met.

Protect Your Application from Broken Function-Level Authorization with AppSecEngineer

Broken function-level authorization means that even though your application has implemented access controls, it's not doing a very good job of enforcing them. It's the vulnerability that sneaky hackers exploit to gain access to restricted areas and cause all sorts of chaos. The consequences of broken function-level authorization are far-reaching. Unauthorized users can gain access to functionalities they shouldn't have, leading to unauthorized data manipulation, exposure of sensitive information, and even privilege escalation. It's like granting a random person the ability to execute administrative commands or access confidential customer data.

To address this issue, developers need to implement robust access control mechanisms, thoroughly test their implementation, and regularly review and update security configurations. And how can they do that? Through proper and comprehensive application security training.

Here at AppSecEngineer, we will help you never ship a line of bad code again. With our complete arsenal of training materials, starting from 60+ courses and 1000+ hands-on labs (not to mention Challenges and Playgrounds!), we will not only make sure that your products are safe, but we will also help boost the productivity of your entire team!

Don't let insecure code hold you back. Visit us at www.appsecengineer.com.

Source for article
Vishnu Prasad K

Vishnu Prasad K

Vishnu Prasad is a DevSecOps Lead at we45. A DevSecOps and Security Automation wizard, he has implemented security in DevOps for numerous Fortune 500 companies. Vishnu has experience in Continuous Integration and Continuous Delivery across various verticals, using tools like Jenkins, Selenium, Docker, and other DevOps tools. His role sees him automating SAST, DAST, and SCA security tools at every phase of the build pipeline. He commands knowledge of every major security tool out there, including ZAP, Burp, Findsecbugs, and npm audit, among many others. He's a tireless innovator, having Dockerized his entire security automation process for cross-platform support to build pipelines seamlessly. When AFK, he is either pouring over Investment journals or in the swimming pool.

Vishnu Prasad K


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