Cross-site Scripting (XSS) is a type of security vulnerability that allows attackers to inject malicious script code into trusted websites, which then gets executed by the browsers of its users. XSS attacks are common and pose a significant threat to web applications that fail to sanitize user-generated inputs properly.

This long read post explores documented vulnerability CVE-2023-4433, focusing on the stored XSS found in the GitHub repository cockpit-hq/cockpit prior to version 2.6.4. We will discuss the core aspects of this vulnerability, including code snippets, links to original references, and exploit details. This post aims to provide an exclusive understanding of the vulnerability while using simple language to ensure broad comprehension.

Summary of CVE-2023-4433

CVE-2023-4433 is a stored Cross-site Scripting (XSS) vulnerability found in the cockpit-hq/cockpit GitHub repository, specifically in versions prior to 2.6.4. This vulnerability poses a significant threat to users' data and enables attackers to exploit it by injecting malicious script code into the web application.

The Vulnerable Code Snippet

An issue was discovered in the cockpit-hq/cockpit GitHub repository code, which processes user-generated input without proper sanitization. This vulnerability leads to stored XSS attacks when the user input contains malicious script code. Here is a simplified example of the vulnerable code from the cockpit-hq/cockpit application:

function display_username(username) {
  // vulnerable code
  var user_element = document.createElement("div");
  user_element.innerHTML = username;
  document.body.appendChild(user_element);
}

In this code snippet, the display_username() function takes a username parameter and creates an HTML <div>-element containing the username text. It then appends this element to the document's body. Due to the lack of proper input sanitization, this code is vulnerable to stored XSS attacks.

Exploit Details

An attacker could exploit this vulnerability by injecting malicious script code, such as <script>alert("XSS")</script>, into the user input. For example, if the attacker enters this script code as their username, the unsanitized input gets processed and stored in the web application. When the application later displays this username, the malicious script code runs in users' browsers:

display_username('<script>alert("XSS")</script>');

This exploit allows the attacker to compromise users' data and execute harmful actions on their behalf, such as stealing cookies or session tokens.

Original References

Several resources detail the CVE-2023-4433 vulnerability, including a report by the National Vulnerability Database (NVD) and the official GitHub Advisory Database:

1. NVD Report: https://nvd.nist.gov/vuln/detail/CVE-2023-4433
2. GitHub Advisory: https://github.com/advisories/GHSA-xx73-22rh-j9scanner

Mitigation

Cockpit-hq/cockpit's developers have fixed this vulnerability in version 2.6.4. Updating to the latest version is critical for protecting users' security. Additionally, web application developers should implement proper input sanitization and validation measures to prevent XSS attacks.

Conclusion

Understanding and preventing stored XSS vulnerabilities like CVE-2023-4433 is essential for web application security. By discussing this CVE's code snippet, exploit details, and original references, this post aims to provide an exclusive look into the inner workings of this security vulnerability. Awareness, prevention, and timely patching of vulnerabilities are crucial elements in maintaining web applications' security and user safety.

Timeline

Published on: 08/19/2023 01:15:00 UTC
Last modified on: 08/23/2023 16:58:00 UTC