09 Mar, 2023

Access control weaknesses

Vulnerability Assessment as a Service (VAaaS)

Tests systems and applications for vulnerabilities to address weaknesses.

Access control weaknesses refer to vulnerabilities in the security measures that are put in place to restrict or regulate access to a system, network, or data. Access control is an essential component of information security and helps to prevent unauthorized access, modification, or disclosure of sensitive data.

Access control weaknesses can take various forms, including:

  • Weak or easily guessed passwords: Passwords that are easy to guess or crack are a significant vulnerability, as they allow unauthorized users to gain access to the system or data.

  • Lack of multifactor authentication: Multifactor authentication, which requires users to provide multiple forms of identification (such as a password and a fingerprint or a security token), can enhance access control by making it harder for unauthorized users to gain access.

  • Misconfigured access control lists: Access control lists (ACLs) define which users or groups can access specific resources, such as files or directories. Misconfigured ACLs can allow unauthorized users to gain access to sensitive data.

  • Insufficient or incorrect permissions: Users should be granted the least amount of access necessary to perform their job functions. Giving users more permissions than they need can increase the risk of unauthorized access or accidental data leaks.

  • Lack of auditing and monitoring: Without proper auditing and monitoring, it can be challenging to detect unauthorized access or other security breaches.

Example of vulnerable code on different programming languages:


in Java:

				
					public void viewUserProfile(String userId) {
    User user = getUserById(userId);
    if (user != null) {
        System.out.println("User Name: " + user.getName());
        System.out.println("Email Address: " + user.getEmail());
    }
}

				
			

 

In this code, the viewUserProfile method is used to display a user’s profile information. However, there is no access control check to ensure that the user calling this method is authorized to view the profile. An attacker could exploit this vulnerability by passing in a different user ID and gaining access to another user’s profile.

• in Python:

				
					def read_file(filename):
    with open(filename, 'r') as f:
        contents = f.read()
    return contents

				
			


This code reads the contents of a file using Python’s built-in open function. However, there is no access control check to ensure that the user calling this function is authorized to read the file. An attacker could exploit this vulnerability by passing in a different filename and gaining access to sensitive data.

• in PHP:

				
					if ($_SESSION['isAdmin']) {
    // Allow the user to delete a record
    deleteRecord($_GET['recordId']);
}

				
			


In this code, the deleteRecord function is only called if the user has the isAdmin flag set in their session. However, there is no access control check to ensure that the user calling this code is authorized to delete the record. An attacker could exploit this vulnerability by modifying the isAdmin flag in their session and gaining access to delete records they are not authorized to delete.

Examples of exploitation Access control weaknesses

Password guessing:

Weak or easily guessable passwords can be exploited by attackers to gain unauthorized access to a system or data. Attackers can use automated tools to try various combinations of passwords until they find the correct one.

Session hijacking:

If a user’s session ID is compromised, an attacker can use it to impersonate the user and gain access to sensitive data or perform unauthorized actions.

Directory traversal:

A directory traversal attack exploits a vulnerability in which an attacker can navigate outside the root directory and access files they are not authorized to view. This can be done by manipulating URLs or file paths.

Privilege escalation:

If a user is granted more permissions than they need, an attacker can exploit this vulnerability to gain elevated privileges and access sensitive data or perform unauthorized actions.

Social engineering:

Attackers can use social engineering techniques to trick users into disclosing their login credentials or other sensitive information, allowing them to gain unauthorized access.

Brute force attacks:

Attackers can use brute force attacks to gain unauthorized access to a system or data by trying various combinations of login credentials until they find the correct ones.

Privilege escalation techniques for Access control weaknesses

Exploiting vulnerabilities:

Attackers can exploit vulnerabilities in software or operating systems to gain elevated privileges. This can be done by exploiting buffer overflow, injection attacks, or other vulnerabilities.

Misconfiguration:

Misconfigured access control lists or permission settings can lead to privilege escalation. Attackers can exploit these misconfigurations to gain elevated privileges and access to sensitive resources.

Impersonation:

Attackers can impersonate a user with higher privileges to gain access to resources they would not normally be authorized to access. This can be done by stealing or guessing login credentials, or by exploiting vulnerabilities in authentication mechanisms.

Abusing functionality:

Some applications or systems may have features or functionality that can be abused to gain elevated privileges. For example, an attacker may be able to exploit a feature that allows users to execute arbitrary code or run system commands.

Exploiting default settings:

Default settings in software or operating systems may provide higher privileges than necessary. Attackers can exploit these default settings to gain elevated privileges.

Social engineering:

Attackers can use social engineering techniques to trick users with higher privileges into providing access to sensitive resources or elevating their permissions.

General methodology and checklist for Access control weaknesses

Methodology:

  1. Identify the access control requirements: The first step is to understand the access control requirements for the application or system being tested. This includes identifying the authorized users, the types of data or resources they are authorized to access, and the access control mechanisms in place.

  2. Map out the application or system: Next, map out the application or system being tested to identify all the entry points and user actions that could potentially lead to access control vulnerabilities.

  3. Test for direct object references: Test for direct object references by attempting to access resources that should not be accessible. For example, attempt to access a resource by changing the resource ID in the URL.

  4. Test for privilege escalation: Test for privilege escalation by attempting to gain elevated privileges. For example, attempt to access an administrative function by guessing or stealing login credentials.

  5. Test for indirect object references: Test for indirect object references by attempting to access resources through other resources that should not be accessible. For example, attempt to access a user’s private data by accessing it through another user’s account.

  6. Test for insufficient authorization checks: Test for insufficient authorization checks by attempting to access resources that should require authorization but do not. For example, attempt to access a restricted resource without providing any credentials.

  7. Test for business logic vulnerabilities: Test for business logic vulnerabilities that could lead to access control weaknesses. For example, test for vulnerabilities in workflow processes that could allow unauthorized access to resources.

  8. Test for error handling: Test for error handling by attempting to trigger errors in the application or system being tested. This can help identify access control vulnerabilities that are not immediately apparent.

  9. Review access control mechanisms: Review the access control mechanisms in place, including authentication, authorization, and audit logging. This can help identify weaknesses in these mechanisms that could be exploited by attackers.

  10. Document and prioritize vulnerabilities: Document all vulnerabilities identified during testing and prioritize them based on their severity and potential impact on the application or system being tested.

Checklist:

  1. Verify that the authentication mechanisms are functioning properly and that they are adequately protecting the application or system from unauthorized access.

  2. Check that the authorization mechanisms are enforcing proper access control policies and that users are only able to access resources that they are authorized to access.

  3. Test for direct object reference vulnerabilities by attempting to access resources directly by manipulating URLs or resource identifiers.

  4. Test for indirect object reference vulnerabilities by attempting to access resources indirectly by exploiting relationships between resources.

  5. Test for privilege escalation vulnerabilities by attempting to gain elevated privileges through exploitation of vulnerabilities in the application or system.

  6. Test for insufficient authorization checks by attempting to access resources that should require authorization but do not.

  7. Review the access control policies to ensure that they are complete, accurate, and up to date.

  8. Test for business logic vulnerabilities that could lead to access control weaknesses.

  9. Review the audit logging mechanisms to ensure that they are properly recording all access attempts and that they are adequately protected from tampering.

  10. Prioritize and document all findings, including their severity and potential impact on the application or system being tested.

Tools set for exploiting Access control weaknesses

Manual Tools:

  • Burp Suite: A web application security testing tool that can be used to manually identify and exploit access control vulnerabilities, such as insufficient authorization checks and direct object references.

  • Postman: A REST API development and testing tool that can be used to manually test access control vulnerabilities, such as insufficient authorization checks and privilege escalation vulnerabilities.

  • Manual testing frameworks: Manual testing frameworks, such as the OWASP Testing Guide and the NIST SP 800-115, provide guidance and checklists for identifying and exploiting access control weaknesses.

  • Command-line tools: Command-line tools, such as cURL and wget, can be used to manually test access control vulnerabilities, such as direct object references and insufficient authorization checks.

Automated Tools:

  • Nessus: A vulnerability scanner that can be used to automatically detect access control vulnerabilities, such as weak authentication and authorization mechanisms.

  • Acunetix: A web vulnerability scanner that can be used to automatically detect access control vulnerabilities, such as insufficient authorization checks and direct object references.

  • Nmap: A network exploration and vulnerability scanning tool that can be used to automatically identify access control vulnerabilities, such as open ports and unsecured services.

  • OpenVAS: An open source vulnerability scanner that can be used to automatically detect access control vulnerabilities, such as weak authentication mechanisms and privilege escalation vulnerabilities.

  • Nikto: A web server scanner that can be used to automatically detect access control vulnerabilities, such as default credentials and directory listing vulnerabilities.

  • Vega: A web vulnerability scanner and testing platform that can be used to automatically detect access control vulnerabilities, such as insufficient authorization checks and direct object references.

  • SQLMap: An automated SQL injection tool that can be used to exploit access control vulnerabilities, such as weak authentication mechanisms and privilege escalation vulnerabilities.

  • Metasploit: A penetration testing tool that can be used to automatically exploit access control vulnerabilities, such as weak authentication mechanisms and privilege escalation vulnerabilities.

  • ZAP: A web application security scanner that can be used to automatically detect access control vulnerabilities, such as insufficient authorization checks and direct object references.

Browser Plugins:

  • Tamper Data: A Firefox add-on that can be used to intercept and modify HTTP/HTTPS requests and responses, allowing testers to manually test access control vulnerabilities.

  • Cookie Editor: A Chrome extension that can be used to manually edit and modify cookies, allowing testers to test access control vulnerabilities related to cookie-based authentication mechanisms.

  • EditThisCookie: A Chrome extension that can be used to edit and manipulate cookies, allowing testers to test access control vulnerabilities related to cookie-based authentication mechanisms.

  • ModHeader: A Chrome extension that can be used to modify HTTP headers, allowing testers to test access control vulnerabilities related to header-based authentication mechanisms.

  • LiveHTTPHeaders: A Firefox add-on that can be used to view and modify HTTP headers, allowing testers to test access control vulnerabilities related to header-based authentication mechanisms.

  • Web Developer: A browser extension that can be used to modify and manipulate web pages, allowing testers to test access control vulnerabilities related to client-side access control mechanisms.

  • HackBar: A Firefox add-on that can be used to test and manipulate URL parameters and data, allowing testers to test access control vulnerabilities related to URL-based access control mechanisms.

Average CVSS score of stack Access control weaknesses

The average CVSS score of stack access control weaknesses can vary widely depending on the specific vulnerabilities and their severity. However, in general, access control vulnerabilities are considered to be high or critical severity, with CVSS scores ranging from 7.0 to 10.0.

Some common examples of access control vulnerabilities and their average CVSS scores include:

  1. Insufficient authentication: CVSS score 8.0 – 10.0

  2. Insufficient authorization: CVSS score 7.0 – 9.0

  3. Direct object reference: CVSS score 7.5 – 9.0

  4. Privilege escalation: CVSS score 8.0 – 9.0

  5. Broken access control: CVSS score 8.0 – 10.0

It’s worth noting that CVSS scores are just one metric for measuring the severity of a vulnerability, and that other factors such as the impact on the organization and the likelihood of exploitation should also be considered when prioritizing and addressing access control weaknesses.

The Common Weakness Enumeration (CWE)

• CWE-285: Improper Authorization – This CWE refers to weaknesses related to authorization mechanisms that are not properly implemented, allowing unauthorized access to resources.

• CWE-287: Improper Authentication – This CWE refers to weaknesses related to authentication mechanisms that are not properly implemented, allowing attackers to bypass authentication and gain unauthorized access.

• CWE-306: Missing Authentication for Critical Function – This CWE refers to weaknesses related to critical functions that are not properly protected by authentication mechanisms, allowing unauthorized access to these functions.

• CWE-346: Origin Validation Error – This CWE refers to weaknesses related to web applications that do not properly validate the origin of requests, allowing attackers to perform cross-site request forgery (CSRF) attacks.

• CWE-352: Cross-Site Request Forgery (CSRF) – This CWE refers to weaknesses related to web applications that do not properly validate requests, allowing attackers to perform CSRF attacks.

• CWE-434: Unrestricted Upload of File with Dangerous Type – This CWE refers to weaknesses related to web applications that allow users to upload files without proper validation, which can lead to the uploading of malicious files.

• CWE-639: Authorization Bypass Through User-Controlled Key – This CWE refers to weaknesses related to applications that rely on user-controlled keys for authorization, which can be easily bypassed by attackers.

• CWE-732: Incorrect Permission Assignment for Critical Resource – This CWE refers to weaknesses related to applications that incorrectly assign permissions to critical resources, allowing unauthorized access to these resources.

• CWE-759: Use of a One-Way Hash without a Salt – This CWE refers to weaknesses related to applications that use one-way hash functions without a salt, which can make them vulnerable to pre-computed hash attacks.

• CWE-829: Inclusion of Functionality from Untrusted Control Sphere – This CWE refers to weaknesses related to applications that include code from untrusted sources, which can lead to security vulnerabilities, including access control weaknesses.

CVES related to Access control weaknesses

• CVE-2017-12251 – A vulnerability in the web console of the Cisco Cloud Services Platform (CSP) 2100 could allow an authenticated, remote attacker to interact maliciously with the services or virtual machines (VMs) operating remotely on an affected CSP device. The vulnerability is due to weaknesses in the generation of certain authentication mechanisms in the URL of the web console. An attacker could exploit this vulnerability by browsing to one of the hosted VMs’ URLs in Cisco CSP and viewing specific patterns that control the web application’s mechanisms for authentication control. An exploit could allow the attacker to access a specific VM on the CSP, which causes a complete loss of the system’s confidentiality, integrity, and availability. This vulnerability affects Cisco Cloud Services Platform (CSP) 2100 running software release 2.1.0, 2.1.1, 2.1.2, 2.2.0, 2.2.1, or 2.2.2. Cisco Bug IDs: CSCve64690.

• CVE-2002-1747 – Vtun 2.5b1 does not authenticate forwarded packets, which allows remote attackers to inject data into user sessions without detection, and possibly control the data contents via cut-and-paste attacks on ECB.

Access control weaknesses exploits

  • SQL injection – this type of attack allows an attacker to bypass access controls and gain access to sensitive data by manipulating SQL queries.

  • Cross-site scripting (XSS) – this type of attack allows an attacker to inject malicious code into a web page, which can then be executed in the browser of other users, allowing the attacker to steal session tokens and bypass access controls.

  • Cross-site request forgery (CSRF) – this type of attack allows an attacker to forge requests that are sent to a web application from a user that has already authenticated, allowing the attacker to execute unauthorized actions on the application.

  • Broken access control – this type of attack allows an attacker to bypass access controls by manipulating or intercepting requests that are sent to the application.

  • Privilege escalation – this type of attack allows an attacker to elevate their privileges within the application or operating system, giving them access to resources that they are not authorized to access.

  • Session hijacking – this type of attack allows an attacker to take over a user’s session by stealing their session ID, allowing the attacker to bypass authentication and access resources that are restricted to that user.

  • Directory traversal – this type of attack allows an attacker to access files outside of the intended directory structure, allowing them to access sensitive files that they are not authorized to access.

  • Insufficient authentication – this type of attack allows an attacker to bypass authentication controls by exploiting weaknesses in the authentication mechanism, such as weak passwords or the use of easily guessable secret questions.

  • Insufficient authorization – this type of attack allows an attacker to bypass authorization controls by exploiting weaknesses in the authorization mechanism, such as failing to validate input or not properly checking permissions.

  • Insecure direct object reference (IDOR) – this type of attack allows an attacker to access or manipulate objects directly, bypassing access controls that are intended to restrict their access.

Practicing in test for Access control weaknesses

Capture the flag (CTF) challenges – There are several CTF challenges available online that focus on access control weaknesses. These challenges provide a safe and controlled environment for practicing access control testing and can help you develop your skills in identifying and exploiting access control vulnerabilities.

Vulnerable applications – There are several intentionally vulnerable applications available for practicing access control testing, such as OWASP Juice Shop and Damn Vulnerable Web Application (DVWA). These applications provide a safe and legal environment for practicing access control testing and can help you learn how to identify and exploit access control weaknesses.

Bug bounty programs – Many companies offer bug bounty programs that reward security researchers for identifying and reporting security vulnerabilities, including access control weaknesses. Participating in these programs can provide an opportunity to practice access control testing on real-world applications while earning rewards for your efforts.

Online courses and tutorials – There are several online courses and tutorials available that focus on access control testing, such as those offered by OWASP and SANS Institute. These courses can help you develop your skills in identifying and exploiting access control vulnerabilities.

Penetration testing labs – Some companies offer penetration testing labs that provide a safe and legal environment for practicing access control testing. These labs typically simulate real-world scenarios and can help you develop your skills in identifying and exploiting access control weaknesses.

For study Access control weaknesses

OWASP – The Open Web Application Security Project (OWASP) is a non-profit organization that provides resources and guidelines for improving the security of web applications. Their website offers a variety of resources related to access control, including the OWASP Top 10, which lists the top 10 most critical web application security risks, and the Access Control Cheat Sheet, which provides guidance on how to implement access control correctly.

SANS Institute – The SANS Institute is a training and certification organization that offers courses and resources related to cybersecurity. Their website offers a variety of resources related to access control, including the SANS Top 25, which lists the 25 most dangerous software errors, and the Access Control Fundamentals course, which provides an introduction to access control.

NIST – The National Institute of Standards and Technology (NIST) is a government agency that provides guidance and resources related to cybersecurity. Their website offers a variety of resources related to access control, including the NIST Cybersecurity Framework, which provides a framework for improving the cybersecurity of organizations.

Books – There are several books available that focus on access control and security, such as “The Web Application Hacker’s Handbook” by Dafydd Stuttard and Marcus Pinto and “Security Engineering: A Guide to Building Dependable Distributed Systems” by Ross Anderson.

Online courses – There are several online courses available that focus on access control, such as those offered by Udemy and Coursera.

Books with review of Access control weaknesses

The Web Application Hacker’s Handbook: Finding and Exploiting Security Flaws by Dafydd Stuttard and Marcus Pinto – This book provides an in-depth guide to identifying and exploiting security vulnerabilities in web applications, including access control weaknesses.

Hacking Exposed: Web Applications by Joel Scambray, Mike Shema, and Caleb Sima – This book provides a comprehensive guide to web application security, including access control weaknesses.

Web Security Testing Cookbook: Systematic Techniques to Find Problems Fast by Paco Hope and Ben Walther – This book provides a collection of recipes for testing web applications, including techniques for identifying and exploiting access control weaknesses.

Black Hat Python: Python Programming for Hackers and Pentesters by Justin Seitz – This book provides a guide to using Python for security testing and includes examples of how to identify and exploit access control weaknesses.

Gray Hat Hacking: The Ethical Hacker’s Handbook by Allen Harper, Daniel Regalado, et al. – This book provides an overview of ethical hacking and includes chapters on web application security and access control weaknesses.

The Basics of Web Hacking: Tools and Techniques to Attack the Web by Josh Pauli – This book provides an introduction to web hacking and includes chapters on identifying and exploiting access control weaknesses.

Securing Web Applications: The Definitive Guide for JavaScript Developers by Mario Casciaro – This book provides a guide to securing web applications, including techniques for addressing access control weaknesses.

Security Engineering: A Guide to Building Dependable Distributed Systems by Ross Anderson – This book provides an overview of security engineering and includes chapters on access control and authorization.

The Shellcoder’s Handbook: Discovering and Exploiting Security Holes by Chris Anley, John Heasman, et al. – This book provides a guide to exploiting security vulnerabilities, including access control weaknesses.

Cybersecurity for Executives: A Practical Guide by Gregory J. Touhill and C. Joseph Touhill – This book provides a practical guide to cybersecurity for executives and includes chapters on access control and authorization.

List of payloads Access control weaknesses

  • Accessing unauthorized pages or directories by manipulating URLs or parameters

  • Modifying cookies to bypass authentication or access restricted areas

  • Forcing access to administrative or privileged functionality by changing HTTP request parameters or variables

  • Using default or weak passwords to gain access to systems or accounts

  • Brute-forcing passwords or guessing credentials through social engineering tactics

  • Exploiting race conditions or timing vulnerabilities to access restricted functionality

  • Using SQL injection to gain unauthorized access to databases or data

  • Forging authentication tokens or session IDs to bypass access controls

  • Intercepting or manipulating network traffic to gain unauthorized access

  • Leveraging business logic flaws to gain unauthorized access or privileges.

How to be protected from Access control weaknesses

  1. Implement strong authentication and password policies, including the use of multi-factor authentication where possible.

  2. Ensure that all user accounts have appropriate access levels and permissions, and regularly review and update these permissions as necessary.

  3. Use encryption to protect sensitive data, both in transit and at rest.

  4. Regularly monitor logs and activity to detect and respond to any unauthorized access attempts or suspicious activity.

  5. Implement access controls at every layer of your infrastructure, including web applications, operating systems, and network infrastructure.

  6. Regularly test your access controls using vulnerability assessments and penetration testing to identify any weaknesses and address them before they can be exploited by attackers.

  7. Educate employees and users about the importance of strong passwords, avoiding phishing scams, and other security best practices.

  8. Implement role-based access control (RBAC) to ensure that users only have access to the resources and data necessary for their job function.

  9. Implement least privilege access control to ensure that users only have the minimum access necessary to perform their job functions.

  10. Regularly apply software updates and patches to all systems and applications to address known security vulnerabilities.

Mitigations for Access control weaknesses

  1. Implement strong authentication mechanisms, such as multi-factor authentication, to ensure that only authorized users can access the system or application.

  2. Use RBAC (role-based access control) to assign specific roles to users and control what actions they can perform.

  3. Implement least privilege access control to ensure that users only have access to the minimum resources necessary to perform their job functions.

  4. Implement access controls at every layer of your infrastructure, including web applications, operating systems, and network infrastructure.

  5. Regularly monitor logs and activity to detect and respond to any unauthorized access attempts or suspicious activity.

  6. Implement encryption to protect sensitive data, both in transit and at rest.

  7. Regularly test your access controls using vulnerability assessments and penetration testing to identify any weaknesses and address them before they can be exploited by attackers.

  8. Implement strong password policies and enforce password expiration and complexity requirements.

  9. Regularly apply software updates and patches to all systems and applications to address known security vulnerabilities.

  10. Educate employees and users about the importance of strong passwords, avoiding phishing scams, and other security best practices.

Conclusion

Access control weaknesses can pose a serious threat to the security of an organization’s systems and data. Attackers who exploit these weaknesses can gain unauthorized access to sensitive data, modify or delete critical information, and even take control of entire systems.

To prevent access control weaknesses, it is important to implement strong access controls at every layer of your infrastructure, including web applications, operating systems, and network infrastructure. This includes implementing RBAC and least privilege access control, using strong authentication mechanisms, and regularly testing your access controls using vulnerability assessments and penetration testing.

In addition, organizations should regularly monitor logs and activity to detect and respond to any unauthorized access attempts or suspicious activity, and implement encryption to protect sensitive data. By following these best practices, organizations can reduce the risk of access control weaknesses and help protect their systems and data from unauthorized access.

Other Services

Ready to secure?

Let's get in touch