Client Side Vulnerabilities / Websockets

Web and API


WebSockets is a Client Side Vulnerability (CWE-811) that occurs in Web and API applications. It is an attack technique used to exploit a weakness in the communication layer between the client and the server. It allows an attacker to gain access to the application's backend and data using specially crafted requests. By exploiting this vulnerability, an attacker can gain access to confidential information, modify data, or even take control of the application. The OWASP Testing Guide states that WebSocket attacks should be tested for during penetration tests.


The risk associated with this vulnerability is high as it can potentially lead to data theft, data manipulation, or full application takeover. Attackers can use these methods to gain access to confidential information or modify data, which can have serious consequences.


The best way to mitigate the risk associated with WebSockets is to use secure protocols such as HTTPS and TLS. Additionally, developers should ensure that the application is properly configured and that all requests are properly authenticated. It is also important to regularly monitor the application logs to detect any suspicious activity.


The following code is an example of a WebSocket vulnerability from the CVE directory. The code contains a Remote Code Execution (RCE) vulnerability which allows an attacker to execute arbitrary code on the target system.

// Create a WebSocket server
var server = new WebSocketServer(
  {port: 8080},
  function(socket) {
    // Handle a connection
    socket.on('message', function(data) {
      // Execute the data as code

Curious? Convinced? Interested?

Arrange a no-obligation consultation with one of our product experts today.