CVE-2023-4422: Understanding and Exploiting Cross-Site Scripting (XSS) in cockpit-hq/cockpit Prior to 2.6.3

Recently, a security vulnerability which falls under the domain of Cross-site Scripting (XSS) was discovered in the GitHub repository cockpit-hq/cockpit. In this post, we are going to understand what Cross-site Scripting (XSS) is, how it can be exploited, and the specific details of the vulnerability identified by CVE-2023-4422 that affects this repository up to version 2.6.2.

What is Cross-Site Scripting (XSS)?

Cross-site Scripting (XSS) is a type of security vulnerability that allows attackers to inject malicious client-side scripts into web pages viewed by other users. In other words, it is a weakness that allows hackers to compromise the interaction between an application and its users. XSS vulnerabilities occur when an application includes user-generated data in its output without properly validating or encoding it.

DOM-based XSS

In this instance, we are dealing with a Stored XSS vulnerability, where the malicious script is stored on the server and executed every time the affected page is loaded.

Exploitation

Exploiting an XSS vulnerability typically involves injecting a malicious script into user-generated data. This script will then be executed in the context of the vulnerable application, allowing the attacker to perform actions on behalf of the victims or access their sensitive data. Possible consequences include cookie theft, redirection to malicious websites, and exposure of personal information.

## CVE-2023-4422: Stored XSS in cockpit-hq/cockpit

Let's delve into the specific details of the vulnerability identified by CVE-2023-4422, which affects the cockpit-hq/cockpit repository up to version 2.6.2.

The vulnerability exists in the following file

/path/to/cockpit/upload/handle/Upload.php

The code responsible for handling the uploaded file content does not adequately validate or sanitize user-generated data, making it vulnerable to XSS.

Proof of Concept

Let's explore the exploit for this Stored XSS vulnerability. Consider the following malicious payload crafted to execute an alert displaying "XSS":

<svg onload="alert('XSS')">

To exploit the vulnerability, an attacker can upload a file containing this malicious payload. When the file is uploaded, the application will process and store the file content without properly validating it. The next time the application displays the file content, the malicious script will be executed, compromising the interaction between the application and its users.

Solution

The cockpit-hq/cockpit repository has addressed this vulnerability in version 2.6.3. To mitigate the risk, it is recommended to update your deployed application to this version. Additionally, users are urged to validate and sanitize user-generated data thoroughly and implement proper encoding techniques to prevent such vulnerabilities in the future.

Conclusion

XSS vulnerabilities remain a common security challenge for application developers. Understanding the implications of Cross-site Scripting, particularly the Stored XSS vulnerability discussed in this CVE-2023-4422 case, highlights the importance of thoroughly validating and safely handling user-generated data. By staying up-to-date with security best practices and the latest releases of the software we use, we can minimize the risks associated with such vulnerabilities.

For more information on the CVE, please refer to the CVE Details page. To see the fix implemented in the cockpit-hq/cockpit repository, visit their GitHub repository.

Timeline

Published on: 08/18/2023 19:15:00 UTC
Last modified on: 08/22/2023 00:58:00 UTC