It is important to understand OWASP broken access control examples because they can help organizations identify potential security weaknesses in their applications and take steps to remediate them before they can be exploited. Understanding real-world examples of broken access control incidents can also help organizations understand the impact that these types of vulnerabilities can have on their business and take appropriate measures to prevent similar incidents from occurring.
Moreover, understanding broken access control examples can also help organizations understand the various attack vectors that can be used to exploit these types of vulnerabilities, and can help to inform their security strategies by highlighting areas that require additional security controls or monitoring.
What is OWASP Broken Access Control?
OWASP Broken Access Control refers to a vulnerability or flaw in web application security where the application’s access control mechanisms are not properly implemented, leading to unauthorized access to restricted resources or sensitive information. By exploiting this vulnerability This vulnerability can occur in various forms, such as bypassing authentication, inadequate session management, forced browsing, or lack of access control checks on APIs.
4 OWASP Broken Access Control Attack Examples:
- Bypassing authentication by manipulating URL or HTTP parameters
- Inadequate session management, leading to session hijacking or fixation
- Using forced browsing to access restricted resources
- Lack of access control checks on APIs, leading to unauthorized access to sensitive data
Bypassing authentication by manipulating URL or HTTP parameters
An example of bypassing authentication by manipulating URL or HTTP parameters would be a web application that allows users to access restricted pages after logging in. The application uses a parameter in the URL, such as a session ID, to track the user’s authentication status. If the session ID can be easily manipulated, an attacker could change the ID in the URL to access restricted pages without logging in.
For instance, if the URL for a restricted page is
http://example.com/restricted.html?session_id=abc123, an attacker could change the
session_id parameter in the URL to
http://example.com/restricted.html?session_id=def456 to bypass authentication and access the restricted page.
This vulnerability can be prevented by properly validating and securely storing the session ID on the server and implementing proper access controls.
Inadequate session management, leading to session hijacking or fixation
An example of OWASP Broken Access Control with inadequate session management leading to session hijacking or fixation would be a web application that does not properly manage user sessions. For example, if the application does not use secure session IDs and does not properly expire or invalidate sessions after a certain amount of time or after a user logs out, an attacker could potentially steal the session ID and use it to hijack the user’s session.
For instance, consider a web application where users log in and are given a session ID that is stored in a cookie. If the session ID is easily predictable or the cookie is not properly secured, an attacker could steal the session ID and use it to access the user’s account without logging in. Similarly, if the session ID is not invalidated after a user logs out, an attacker could potentially reuse the session ID to continue accessing the user’s account even after the user has logged out.
Forced browsing to access restricted resources
An example of OWASP Broken Access Control attack using forced browsing to access restricted resources is when a user is able to access restricted pages or resources by simply changing the URL or using direct links. For instance, consider a web application with a page for administrators only, accessible at
http://example.com/admin.html. If the application does not properly check for user permissions before displaying the page, a user could access the page by simply navigating to the URL, even if they are not an administrator.
This vulnerability occurs when the application relies solely on the client-side to control access to restricted resources, rather than properly checking user permissions on the server-side. An attacker could use forced browsing to access sensitive information, such as confidential data or confidential files, by simply changing the URL or using direct links.
Lack of access control checks on APIs, leading to unauthorized access to sensitive data
An example of OWASP Broken Access Control attack due to lack of access control checks on APIs is when an application’s API does not properly check for user permissions before returning sensitive data. For instance, consider a web application with a REST API that returns sensitive information about a user’s account, such as their password or billing information. If the API does not properly check the user’s permissions before returning the data, an attacker could potentially access sensitive information by simply making API requests, even if they are not authorized to do so.
This vulnerability occurs when the API does not properly implement access control checks, allowing unauthorized access to sensitive information. An attacker could use this vulnerability to access confidential information, steal sensitive data, or perform other malicious actions.
Which are the most common methods used to exploit Broken Access Control vulnerabilities?
It is important for organizations to understand these methods and implement appropriate countermeasures, such as proper session management, strong authentication and access controls, and secure coding practices, to prevent exploitation and protect sensitive information.
Here are seven most common methods used to exploit OWASP broken access control vulnerabilities:
- Session Hijacking
- Session Fixation
- Forced Browsing
- API Exploitation
- URL Tampering
- Brute Force Attacks
- Injection Attacks
Session Hijacking Vulnerability
Session Hijacking is a type of attack in which an attacker takes control of an active user session by stealing the session identifier (such as a cookie or token) and using it to access sensitive information or perform actions as the user.
How Session Hijacking works?
Session hijacking vulnerability is a serious security threat because it can allow an attacker to bypass access controls and access sensitive information or perform unauthorized actions. It is important for organizations to implement proper session management and secure authentication mechanisms to prevent session hijacking and protect sensitive information.
Here’s how Session Hijacking works:
- The attacker intercepts the session identifier, either by sniffing network traffic or by exploiting a vulnerability in the application.
- The attacker uses the stolen session identifier to access the application as the user and perform actions as the user, such as accessing sensitive information, making unauthorized changes, or making unauthorized purchases.
- The attacker can persist in the application as the user until the user logs out or the session expires.
Session Fixation Vulnerability
Session Fixation is a type of attack that exploits a weakness in the way sessions are managed by a web application. The goal of the attacker is to fix a user’s session ID, which is typically stored in a cookie or token, to a specific value.
Once the session ID is fixed, the attacker can then use it to access sensitive information or perform actions as the user. This is because the application will associate the user’s actions with the fixed session ID, even if the user has logged out or closed their browser.
How session fixation works?
Here’s an example of how session fixation can be used to exploit broken access control:
- Attacker fixes the session ID: The attacker tricks the user into visiting a malicious website, which fixes the user’s session ID to a specific value.
- User logs in to the application: The user logs in to the application, which associates the fixed session ID with the user’s session.
- Attacker accesses the user’s session: The attacker uses the fixed session ID to access the user’s session and perform actions as the user, such as accessing sensitive information or making unauthorized changes.
Forced browsing is a type of attack where an attacker manipulates a URL or HTTP parameters to access restricted resources or pages in a web application that are not normally accessible to the attacker. In forced browsing, the attacker is essentially tricking the application into serving up information or pages that the attacker should not have access to.
How Forced browsing vulnerability works?
For example, an attacker could modify a URL to access a resource that is intended for only a specific user, such as an administrative panel. If the application does not properly implement access controls, the attacker can bypass them and gain unauthorized access to sensitive information or perform unauthorized actions.
Forced browsing attacks are often successful because many web applications do not properly validate user input, allowing attackers to manipulate URLs and HTTP parameters to access restricted resources. This is why it is important for organizations to properly implement access controls and validate user input to prevent forced browsing attacks and other types of broken access control attacks.
API Vulnerability Exploits
API Exploitation is a type of attack that targets vulnerabilities in an application’s APIs to bypass access controls and access sensitive information. APIs (Application Programming Interfaces) are a set of protocols, routines, and tools for building software and applications. They allow communication between different components and systems, and are often used to expose data and functionality to external parties.
API exploitation occurs when an attacker is able to bypass access controls and access sensitive information by exploiting vulnerabilities in the API. This can be done by manipulating the parameters in a request, accessing restricted resources directly, or exploiting vulnerabilities such as SQL injection.
How API vulnerability is exploited?
An API might allow a user to retrieve information about a specific customer record, but it may not properly implement access controls to ensure that the user is authorized to access that information. An attacker could exploit this vulnerability by sending a request to the API that includes the customer ID for a different customer, bypassing the access controls and gaining unauthorized access to sensitive information.
URL Tampering Vulnerability
URL tampering is a type of attack that involves manipulating the URL or parameters in a request to bypass access controls and access restricted resources. This can occur when an application does not properly validate input or properly implement access controls.
How URL tampering vulnerability is exploited?
URL tampering is a serious security vulnerability that can result in the compromise of sensitive information and the unauthorized access to restricted resources. It is important for organizations to properly validate input and implement access controls to prevent URL tampering and protect sensitive information.
Here’s an example of how URL tampering can be used to exploit broken access control:
- An attacker identifies a resource that is only accessible to authorized users, such as a sensitive file or sensitive information.
- The attacker examines the URL structure of the application to determine how access control is enforced.
- The attacker manipulates the parameters in the URL or request to bypass the access control checks and access the restricted resource.
For example, if the URL structure of the application is “/app/noaccess.php?id=123”, the attacker may change the value of “id” to “111” in an attempt to access a different restricted resource. If the application does not properly validate input or implement access controls, the attacker may be able to gain unauthorized access to sensitive information.
Brute Force Attacks
A Brute Force Attack is a type of attack that involves guessing a large number of possible combinations of values used to authenticate a user, such as a password or token, until the correct one is found.
In the context of broken access control, a brute force attack can be used to exploit vulnerabilities in the authentication process by guessing the correct login credentials for a user. Once the attacker has the correct login credentials, they can access sensitive information and perform unauthorized actions as the user.
Brute force attacks can be automated, allowing the attacker to try a large number of combinations in a short period of time. They can also be carried out using a dictionary of common passwords or a list of leaked passwords obtained from other data breaches.
How brute force attack works?
A brute force attack involves trying a large number of combinations of values, such as passwords or tokens, to guess the correct one used for authentication. In the context of a command-line interface, a brute force command attack can be performed using automated scripts or tools that run a series of commands to guess the correct login credentials.
For example, a brute force attack against a web application could involve using a script that sends a series of login requests, each with a different username and password combination, until the correct credentials are found. The script could use a list of commonly used passwords or a dictionary of leaked passwords to increase the chances of success.
Another example of a brute force attack using commands is password cracking, which involves using a tool to try a large number of possible passwords until the correct one is found. This can be done using command-line tools such as John the Ripper or Hashcat, which can use a dictionary or a list of possible passwords to crack the password hashes.
It is important to note that brute force attacks can be very resource-intensive and time-consuming, but they can still be successful if the passwords or tokens being guessed are weak or easily guessable.
Injection attacks in web application
Injection attacks are a type of security vulnerability that occur when an attacker is able to inject malicious code into an application. This can occur when an application fails to properly validate user input, allowing the attacker to inject code into the application’s logic and execute it.
By injecting malicious code into an application, attackers can bypass access controls and access sensitive information, perform unauthorized actions, and compromise the security and confidentiality of an organization’s data and systems.
How does Injection attack work in a web application?
Injection attacks can be used to exploit broken access control vulnerabilities in several ways, including:
- SQL Injection: Attackers can inject malicious SQL code into a web application’s database to bypass access controls and access sensitive information.
- Command Injection: Attackers can inject malicious shell commands into a web application to execute them on the server.