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Broken Access Control: Key Information and Prevention Tips to Boost Cybersecurity

Quick Summary: OWASP Broken access control vulnerabilities cause serious damage to web applications or software security because of negligence in the implementation of strict authorization. In this article, you will learn about common broken access control examples and how to overcome these attacks with defensive security measures.
Not all data in your application or system is available to every user. In fact, some data is exclusively available to certain users, like sensitive data is only accessible to admins. There comes the role of an access control mechanism that helps manage data access based on a user’s role and privileges.
What if this mechanism is not properly implemented? The result is that the data will be exposed to unauthorized users, causing a serious security challenge. This is what happens in the case of broken access control.
Broken access control is a critical security challenge that tops the list of OWASP top ten web app risks. In this blog, you will learn more about this vulnerability and tips to prevent it to protect your web apps.
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On This Page
- What is Broken Access Control?
- Causes of Broken Access Control Vulnerability
- Types of Broken Access Control Vulnerabilities
- How Does Broken Access Control Impact Businesses?
- Broken Access Control Attack Techniques Used by Attackers
- Eight Best Security Practices to Prevent Broken Access Control Vulnerabilities
- Protect Your Web Apps with ZeroThreat's Expertise
What is Broken Access Control (BAC)?
A broken access control (BAC) refers to the failure of an application or system to properly limit users' access to its data and resources based on permissions and responsibilities. Due to the lack of this restriction, any user can access prohibited data or resources without requisite permissions. This security flaw can arise due to misconfigurations, improper authentication mechanisms, and inappropriate session management.
For every system and application, different users have varied levels of privileges defining their ability to access data and resources. Not all users have the same privileges and permissions. For instance, a regular user can only view their profile, whereas an admin can edit or modify the data from the backend with extended access rights.
When access controls are loosely implemented, attackers can take advantage of this by various techniques, such as privilege escalation, to gain unauthorized access to data.
What are the Causes Behind Broken Access Control Vulnerability?
Broken access control vulnerability can occur due to many reasons. Knowing these reasons is helpful in understanding how this vulnerability manifests in your system to take appropriate measures to eliminate the potential risks.
Broken Authorization
An authorization mechanism helps restrict users from accessing what they are not permitted to. What if this mechanism is not properly implemented? In that case, an unauthorized user can access data or functionality that only users with higher privileges are entitled to.
For example, a user is able to access a dashboard functionality that is intended for admins by manipulating the URL. As a result, the user is able to modify, delete, or add data. This kind of authorization flaw causes broken access control vulnerability.
An attacker can take advantage of this flaw to manipulate or exfiltrate sensitive data. The attacker can act as a legitimate user when accessing unauthorized functionality or data.
Broken Session Management
Session management is a crucial function of web applications that manage a user’s data and state across multiple requests. When it is implemented improperly, it leads to broken access control causing serious security risks for your data and assets.
Broken session management can allow an attacker to take over a user’s session. It is known as session hijacking, which enables the attacker to perform unauthorized actions and pose as a legitimate user. There can be various reasons for improper session management like predictable session IDs, lack of session termination, session IDs, or tokens visible in URLs.
This security flaw welcomes various risks like privilege escalation, data breaches, and unauthorized access to sensitive data.
Broken Authentication
When a web application fails to validate users accessing protected resources or data properly, it is referred to as broken authentication. An attacker can exploit this type of security flaw to access protected data and resources.
Authentication is an important security layer in an access control mechanism that ensures that only users with valid credentials are able to access data and resources. As a result, it prevents the possibility of an attacker trying to access protected data and resources.
An example of this security flaw is related to JWT (JSON Web Tokens), which is used in web applications to authenticate users. The attacker can alter the signed algorithm of the token in case of a weak mechanism to bypass authentication and access protected information.
Injection Flaws
Injection flaws allow an attacker to insert malicious scripts into legitimate pages that get executed on a victim’s browser when clicked. Besides, the attacker can insert malicious commands like SQL queries that can be executed on the server, leading to SQL injections.
This kind of security flaw occurs when input data provided by users is directly used in an application’s logic without validating and filtering it. As a result, the attacker can bypass access controls to gain access to protected data and resources.
What are the Different Types of Broken Access Control Vulnerabilities?
Let's learn about five common broken access control examples in detail.
1. Insecure Direct Object References (IDOR)
This vulnerability takes place when a web app accidentally exposes internal interfaces, like file paths and database keys in its user interface (UI). This gives attackers a big-time opportunity to exploit confidential data. Attackers can manipulate these references to get access to unauthorized data by changing the URL parameter to access another user's private information or sensitive files.
2. Missing Function Level Access Control
Sometimes, access controls are only implemented at the user interface level, which allows attackers to bypass restrictions by going directly to the server's functions. They become free to perform unauthorized operations, such as accessing administrative functionalities to misuse sensitive data. For example, attackers can access administrative functionalities by directly calling an API endpoint without requiring login details or permissions.
3. Overly Permissive Access Controls
In some cases, access controls are not strictly enforced or provide excessive permissions. As a result, a user is able to access more information than required. It violates the PoLP (Principle of Least Privilege) that emphasizes granting the least required permissions. An attacker can exploit overly permissions to intrude into your backend and steal sensitive data. A typical example of this type of security flaw is when a user is able to access admin settings directly with the URL because there are no restrictions based on user roles and privileges.
4. Failure to Invalidate Sessions
When a user logs out of the session, the associated access rights should be revoked on an immediate basis. Failure to implement this can result in misusage of session tokens or cookies by attackers, as they can easily impersonate authenticated users to gain unauthorized access. So, if the user remains active after logging out, attackers can hijack the session and access the restricted areas of web apps.
5. Insecure Object References in APIs
APIs can sometimes expose confidential data without having to authorize and authenticate users' legitimacy. This inadvertent exposure can lead attackers to access unauthorized resources or perform malicious activities through API endpoints.
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How Does Broken Access Control Impact Businesses?
Let's check out in detail what kind of damage a broken access control causes to businesses.
Data Breaches
Broken access control leads allow unauthorized access to confidential information, such as personal, financial, or proprietary information, which can lead to data breaches. This can result in the theft of valuable data, which may be used for identity theft, fraud, or corporate espionage.
Regulatory Penalties
Non-compliance with data protection regulations (e.g., GDPR, HIPAA) due to weaker access control measures can cause businesses to undergo substantial penalties, which can affect their reputation in the market.
Operational Disruption
Unauthorized access can mess up business operations by enabling abnormal activities such as data deletion, modification, or sabotage. This can severely affect the productivity and service availability of organizations and cause operational downtime.
Increased Security Expenses
As businesses experience potential data breaches, they are likely to emphasize security, which makes them strategize their security plan and opt for advanced and emerging security technologies. This causes them to invest huge amounts.
Broken Access Control Attack Techniques Used by Attackers
There are many techniques that attackers can use to exploit broken access control vulnerabilities to steal data. Understanding these techniques is vital to build stronger defenses and prevent potential attacks. So, let’s check these techniques below.
Privilege Escalation
Attackers can use the privilege escalation technique to exploit weak access controls. It can be divided into two – horizontal escalation and vertical escalation. In the case of a horizontal privilege escalation, an attacker exploits authorization and session vulnerabilities to take access privileges to the same level as another user.
On the other hand, vertical privilege is a technique in which the attacker tries to access resources or data that are accessed by users with higher privileges.
Manipulate Parameters
Attackers can sometimes trick an application into granting access by tweaking URL parameters and form field values. With this technique, they can bypass the access control mechanism to obtain data. For example, a vulnerable website uses an ID parameter in its URL structure to provide information about a specific user. The attacker can manipulate this parameter to reveal information about other users.
Exploit API Endpoints
Another technique to exploit broken access control is abusing APIs. When APIs are not properly secured, they become an easy target for attackers. They can tamper with the inputs or API endpoints to perform unauthorized actions or gain access to data.
Misconfigurations
Attackers can also take advantage of misconfigurations that inadvertently expose sensitive data in public URLs. Misconfigurations can reveal sensitive information that can allow an attacker to obtain access to sensitive data.
Eight Robust Security Measures to Prevent Broken Access Control Vulnerabilities
Now that you have plenty of information about broken access control, it’s time to answer the next big question – how to prevent this threat. Well, the answer to this question somewhat lies in the information that you have already obtained throughout this blog. Yet, we are going to discuss a few broken access control prevention tips and practices to tackle this security challenge more effectively.
These defending security measures cover the details that will make an attacker’s job impossible. So, let’s check out the key steps in broken access control mitigation given below to strengthen security 10X and thwart potential data breaches.
1. Implement Proper Authentication
For validating users' identities, implementing proper authentication measures is indispensable to ensure that only authenticated users are accessing the system. Use robust authentication methods like passwords, multi-factor authentication (MFA), single sign-on (SSO), and biometrics for foolproof validation.
Moreover, you can also employ advanced security techniques like hashing with salt to enforce enhanced security in systems or applications.
2. Implement Authorization Checks
Authorization is the process of allocating users their access based on security protocols and their position. It determines what actions users can take or resources they can utilize.
Additionally, access control lists (ACLs) can be performed, and frameworks that support declarative access control policies can be chosen to streamline authorization checks.
3. Optimize Role-based Access Control
In the RBAC method, the permissions are granted on the basis of users' position rather than considering individuality.
Businesses can define roles based on organizational hierarchy and job responsibilities to provide accessibility accordingly.
4. Employ the Principle of Least Privilege
The principle of least privilege is all about providing access to users that suffice to let them perform their tasks and relevant activities properly. Implementing this security measure ensures that users only have access to the resources and functions that are related to their job roles.
This way, businesses can have a proper track of their work and enable broken access control mitigation.
5. Validate Inputs
With input validation, businesses can ensure that the data received by applications, including APIs, is legitimate and adheres to the expected formats.
By deploying input validation, businesses can thoroughly validate and sanitize the inputs and restrict SQL injection attacks and cross-site scripting.
Last year, cross-Site Scripting (XSS) ranked as the second most common High/Critical Security Vulnerability, accounting for 10.5% of all such vulnerabilities. The average time required for remediation was 100 man-days.
6. Enforce Secured API Design
As APIs can sometimes expose confidential data, enforcing secured API design is pretty vital. Design API security, keeping authentication, encryption, authorization, and validation of API requests in mind.
Deploy industry-standard authentication mechanisms like OAuth 2.0 or JSON Web Tokens (JWT) to secure API endpoints.
Also, it is important to encrypt the confidential data transmitted through APIs using HTTPS/TLS to safeguard it from interception and unauthorized access.
7. Monitor Log Access
Ensure to track logging and monitoring users' activities and accept attempts regularly. To identify and respond to suspicious behavior, it's crucial to log access to sensitive resources, authentication events, and instances where authorization fails.
Utilize security information and event management (SIEM) systems and intrusion detection/prevention systems (IDS/IPS) to examine each and every log and create alerts for abnormal activities.
8. Conduct Uniform Security Audits
According to Thales report, 93% of IT professionals believe security threats are surging significantly, a significant rise from 47% last year.
Ensure that regular security audits are conducted to validate the end-to-end security of web apps.
Enforce penetration testing to mock real-world attacks and check if the system can handle them effectively and security controls are properly deployed into the system.
When addressing any potential vulnerabilities associated with broken access control, priorly implement security patches.
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Broken access control can potentially make the path clear for attackers to manipulate sensitive data. One of the prime examples is OWASP broken access control vulnerability that causes unauthorized access to restricted data. We hope you can overcome these significant security threats with the defensive security measures we have curated for you in this article.
Apart from following these security practices, you can operate reliable security tools like ZeroThreat if you want to experience hands-on the best security scanning for your web apps and APIs in minutes. Try it out for free and you will surely optimize it more often!
Frequently Asked Questions
Is broken access control a serious threat?
Yes, broken access control is a serious threat as it can cause a serious adverse effect to app’s security by allowing unauthorized users to gain access to sensitive resources. This can lead to data breaches, unauthorized modifications, loss of confidentiality, and other security incidents, posing potential risks to security of systems and data.
How can I protect myself from broken access control attacks?
How to determine broken access control vulnerabilities?
What are common broken access control vulnerabilities?
Can broken access control be exploited offline?
Are there any tools to identify broken access control vulnerabilities?
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