CVE-2024-36236: Exploring the DOM-Based XSS Vulnerability in Adobe Experience Manager 6.5.20 and Earlier

Adobe Experience Manager (AEM) is a popular content management system that has been widely used to manage enterprise websites and digital marketing channels. Unfortunately, it has been found to be vulnerable to a DOM-based Cross-Site Scripting (XSS) attack. This vulnerability, classified under CVE-2024-36236, affects AEM versions 6.5.20 and earlier. In this post, we'll discuss the details of this vulnerability, its potential impact, and how we can mitigate it.

Exploit Details

A DOM-based XSS vulnerability occurs when untrusted data is used to update the Document Object Model (DOM) directly, leading to the execution of malicious JavaScript code in the context of the victim's browser session. In this case, an attacker can exploit the flaw by crafting a malicious link that contains JavaScript code. If a user clicks on this link, the code will be executed, potentially compromising the user's session and leading to further attacks. This could include stealing cookie data, redirecting the user to a phishing website or distributing malware.

Here's an example of a code snippet that demonstrates how this vulnerability can be exploited

// Get user input from URL parameter
var userInput = decodeURIComponent(
  location.search.replace(/^(.*\?)/, '')
);

// Directly update DOM element with user input
document.getElementById('example').innerHTML = userInput;

In this code snippet, the user input is retrieved from the URL parameter and is then used to update the innerHTML of the DOM element with the ID example. This allows an attacker to inject malicious code through the URL parameter, which will be executed when the page loads.

Original References

1. CVE-2024-36236 in the NVD (National Vulnerability Database)
2. Adobe Security Bulletin

Mitigation

To protect against this vulnerability, it is recommended to update AEM to the latest version (6.5.20 or later) as soon as possible. Additionally, you can follow these best practices to prevent DOM-based XSS vulnerabilities:

1. Ensure that user input is properly sanitized and encoded before inserting it into the DOM. This can be done using libraries such as DOMPurify or OWASP Java Encoder.
2. Use safe methods to update the DOM instead of using the innerHTML property. For example, you can use the textContent, createTextNode, or createElement methods.
3. Implement a Content Security Policy (CSP) to restrict the sources from which scripts can be loaded, reducing the chances of executing malicious injected code.

Conclusion

CVE-2024-36236 highlights the importance of keeping web applications up-to-date and maintaining a secure coding environment. By understanding such vulnerabilities, updating affected software, and following best practices, developers and administrators can reduce the risk and keep their users safe from potential attacks.

Timeline

Published on: 06/13/2024 08:16:22 UTC
Last modified on: 06/17/2024 20:21:20 UTC