Cross Site WebSocket Hijacking: What It Is and How to Prevent It

Cross Site WebSocket Hijacking (CSWH) is a type of attack that can compromise the security of your website. This attack exploits a vulnerability in the WebSocket protocol, which is used to establish a two-way communication channel between a client and a server. In this article, we will explain what CSWH is, how it works, and what you can do to prevent it.

What is Cross Site WebSocket Hijacking?

CSWH is a type of attack that lets an attacker hijack a WebSocket connection between a client and a server. This attack is possible when the attacker can trick the victim into visiting a malicious website that contains a crafted WebSocket request. When the victim visits this website, the request is sent to the server hosting the WebSocket, and the connection is established. However, the attacker is also able to intercept and manipulate the connection, allowing them to steal sensitive information or perform actions on behalf of the victim.

How Does Cross Site WebSocket Hijacking Work?

In order for CSWH to work, the attacker needs to be able to trick the victim into visiting a malicious website. This can be done in a number of ways, such as by sending a phishing email or by injecting a malicious script into a legitimate website. Once the victim visits the malicious website, the WebSocket request is sent to the server hosting the WebSocket.

At this point, the attacker can intercept and manipulate the connection by sending their own WebSocket requests. These requests can be used to steal sensitive information, such as session cookies or authentication tokens, or to perform actions on behalf of the victim, such as making unauthorized purchases or posting malicious content.

How to Prevent Cross Site WebSocket Hijacking

There are several steps you can take to prevent CSWH:

1. Use SSL/TLS to Encrypt WebSocket Traffic: By using SSL/TLS to encrypt WebSocket traffic, you can prevent attackers from intercepting and reading sensitive information. This is especially important if you are transmitting sensitive data, such as login credentials or payment information.
2. Use a Secure WebSocket Library: When implementing WebSocket functionality on your website, make sure to use a secure WebSocket library that has been vetted by security experts. This will help to ensure that your WebSocket implementation is not vulnerable to CSWH or other types of attacks.
3. Implement CSRF Protection: Cross-Site Request Forgery (CSRF) attacks can be used to execute WebSocket requests on behalf of a victim. To prevent CSRF attacks, you should implement CSRF protection on your website.
4. Use Content Security Policy (CSP): CSP can be used to prevent the execution of malicious scripts on your website. By using CSP, you can prevent attackers from injecting malicious scripts that could be used to initiate a CSWH attack.
5. Use the Same-Origin Policy: The Same-Origin Policy can be used to prevent WebSocket connections from being established between different domains. By using the Same-Origin Policy, you can prevent attackers from establishing a WebSocket connection with your website from a malicious domain.

Frequently Asked Questions

What is a WebSocket?

A WebSocket is a protocol that enables two-way communication between a client and a server. This protocol is used to create real-time web applications, such as chat applications and online games.

What is Cross-Site Request Forgery (CSRF)?

CSRF is a type of attack that tricks a victim into executing an unwanted action on a web application in which they are currently authenticated. This can be done by forging a request that appears to be legitimate but is actually initiated by the attacker.

Why is SSL/TLS important for WebSocket security?

SSL/TLS is important for WebSocket security because it encrypts the data transmitted over the WebSocket connection. Without encryption, an attacker could intercept and read sensitive information, such as login credentials or payment information.

How does Content Security Policy (CSP) work?

CSP is a security feature that enables websites to specify which sources of content are allowed to be executed on their pages. By using CSP, website owners can prevent attackers from injecting malicious scripts that could be used to initiate a CSWH attack.

What is the Same-Origin Policy?

The Same-Origin Policy is a security feature that prevents web pages from making requests to a different domain than the one that served the original page. By using the Same-Origin Policy, website owners can prevent attackers from establishing a WebSocket connection with their website from a malicious domain.

Can Cross Site WebSocket Hijacking be prevented?

Yes, CSWH can be prevented by using SSL/TLS to encrypt WebSocket traffic, using a secure WebSocket library, implementing CSRF protection, using CSP, and using the Same-Origin Policy.

Is Cross Site WebSocket Hijacking a common attack?

CSWH is not as common as other types of web application attacks, such as SQL injection and cross-site scripting (XSS). However, it is still a threat that website owners should be aware of and take steps to prevent.