Authorization bypass is a type of vulnerability that occurs when an attacker is able to gain unauthorized access to a system or application by bypassing the authorization process. Authorization is the process of determining whether a user or system has the appropriate permissions or privileges to access a particular resource or perform a specific action.
Authorization bypass can occur in a variety of ways, such as:
- Bypassing access controls through SQL injection or other methods
- Using default or hardcoded credentials
- Using weak encryption or hashing method
- Using a brute-force attack to guess the credentials
- Lack of rate-limiting on login attempts
- Bypassing access controls by manipulating the URL or hidden form fields
- Bypassing access controls by using session fixation or hijacking
An attacker who is able to bypass authorization can gain unauthorized access to sensitive data or perform actions that they should not be able to, such as altering or deleting data, or using the system for malicious purposes.
To prevent authorization bypass, it’s important to implement a robust authorization mechanism that is appropriate for the specific application and environment, and to regularly review and test it for any vulnerabilities. Additionally, it’s important to use a secure encryption method, use rate-limiting on login attempts, and be aware of common attack vectors such as SQL injection,session fixation and privilege escalation. It’s also important to keep in mind that while authentication is the process of verifying the identity of a user or system, Authorization is the process of determining whether a user or system has the appropriate permissions or privileges to access a particular resource or perform a specific action. It’s also important to implement access controls and role-based access controls (RBAC) to ensure that only authorized users can access specific resources or perform specific actions. This can include using appropriate encryption and secure protocols for transmitting sensitive data, as well as implementing multi-factor authentication to ensure that only authorized users can access the system. Additionally, it’s important to implement regular security audits and testing to identify and address any vulnerabilities in the authorization process. Overall, implementing a robust and well-designed authorization mechanism is crucial for ensuring the security and integrity of a system or application.
Here are a few examples of how authorization bypass can occur in PHP:
- Bypassing access controls through SQL injection: An attacker could use SQL injection to bypass the authorization process and gain unauthorized access to the application.
$username = $_POST['username'];
$query = "SELECT * FROM users WHERE username='$username' AND role='admin'";
$result = mysqli_query($conn, $query);
if(mysqli_num_rows($result) == 1) {
// user is admin, allow access
} else {
// user is not admin, deny access
}In this example, an attacker could use SQL injection to change the query and make it return a result even if the user is not an admin.
- Bypassing access controls by manipulating the URL: An attacker could manipulate the URL or hidden form fields to bypass the authorization process and gain unauthorized access to the application.
$page = $_GET['page'];
if($page == 'admin') {
if($_SESSION['role'] == 'admin') {
// allow access
} else {
// deny access
}
}In this example, an attacker could manipulate the URL or hidden form fields to change the value of the $page variable to ‘admin’ and gain access to the admin page without having the appropriate role.
- Bypassing access controls by using session fixation or hijacking: An attacker could use session fixation or hijacking to bypass the authorization process and gain unauthorized access to the application.
if(isset($_SESSION['username']) && isset($_SESSION['role'])) {
if($_SESSION['role'] == 'admin') {
// allow access
} else {
// deny access
}
}In this example, an attacker could use session fixation or hijacking to hijack a valid session and change the role to ‘admin’ and gain unauthorized access to the application.
These are just examples and there are many ways in which an authorization can be bypassed, so it’s important to have a robust authorization mechanism in place and to regularly review and test it for any vulnerabilities. It’s also important to use a secure encryption method, use rate-limiting on login attempts, and be aware of common attack vectors such as SQL injection,session fixation and privilege escalation.
Here are some sources:
https://www.triaxiomsecurity.com/common-web-application-vulnerabilities-authorization-bypass/
https://cwe.mitre.org/data/definitions/639.html
https://snyk.io/blog/spring-security-authorization-bypass-cve-2022-31692/
This is all for now!
Peace!
