How to Fix CVE-2024-45613 - A High Severity Cross-Site Scripting (XSS) vulnerability in CKEditor 5?

This is another example supporting Cross-site scripting (XSS) vulnerabilities continue to be part of OWASP Top 10 risks. Recently, a high-severity XSS flaw was discovered in CKEditor 5, a popular JavaScript-based rich text editor used on many websites.

On September 25, 2024, the CKEditor development team disclosed a critical Cross-Site Scripting (XSS) vulnerability in the CKEditor 5 clipboard package. This flaw, tracked as CVE-2024-45613, could allow attackers to execute arbitrary JavaScript code by exploiting a specific user action under certain editor configurations. With a CVSS 3.1 base score of 7.2 (High severity), this vulnerability poses a significant risk to websites and applications using vulnerable versions of CKEditor 5.

CKEditor is widely used across the web for providing rich text editing capabilities in content management systems, forums, email clients and many other applications. As such, this vulnerability potentially impacts a large number of websites and their users. Prompt action is required from developers and administrators to update affected CKEditor installations and mitigate the risk of exploitation.

Let's see about the flaw CVE-2024-45613, its potential impact, affected versions, and most importantly - how to detect and mitigate this security risk in your CKEditor 5 implementations.

A Short Introduction to CKEditor 5

CKEditor 5 is a modern, feature-rich JavaScript WYSIWYG editor framework. It provides a flexible and extensible architecture for building customized rich text editing solutions for web applications. Some key features of CKEditor 5 include:

CKEditor 5 is used by many popular content management systems, e-learning platforms, and enterprise applications to provide rich text editing functionality. Its extensibility and powerful features make it a popular choice for developers looking to add sophisticated editing capabilities to their web projects.

Summary of CVE-2024-45613

Here are the key details of the CVE-2024-45613 vulnerability:

The vulnerability stems from Improper Neutralization of Input During Web Page Generation (CWE-79). Under specific configurations, this flaw allows an attacker to inject malicious JavaScript code into the editor content. When triggered by a user action, this injected code can execute in the context of the victim's browser, potentially leading to unauthorized actions, data theft, or further exploitation.

Specifically, the XSS vulnerability can be exploited when the following conditions are met:

When these conditions are satisfied, an attacker who manages to insert malicious content into the editor can potentially execute arbitrary JavaScript code when a specific user action triggers the vulnerability.

The CKEditor security team discovered this vulnerability during an internal security audit. While the exact details of the exploitation method have not been publicly disclosed to prevent potential abuse, the team has emphasized the importance of updating to a patched version promptly.

Impact of CVE-2024-45613

The potential impact of this Cross-Site Scripting vulnerability in CKEditor 5 is significant, particularly for websites and applications that rely on user-generated content. Some of the key risks associated with successful exploitation of CVE-2024-45613 include:

The severity of this vulnerability is amplified by the fact that CKEditor 5 is widely used across many popular websites and applications. This broad attack surface increases the likelihood of exploitation attempts and potential impact on end-users.

Products Affected by CVE-2024-45613

The CVE-2024-45613 vulnerability affects multiple packages within the CKEditor 5 ecosystem. The following table outlines the affected versions:

It's important to note that the vulnerability only affects installations where specific plugins are enabled, as mentioned in the summary section. Configurations that do not use the Block Toolbar plugin in combination with either General HTML Support (with unsafe markup allowed) or the HTML Embed plugin are not vulnerable to this specific XSS issue.

How to Check if Your CKEditor 5 Installation is Vulnerable

To determine if your CKEditor 5 implementation is vulnerable to CVE-2024-45613, follow these steps:

3. Inspect Enabled Plugins: You can check which plugins are enabled in your CKEditor instance by examining your configuration code or using the CKEditor API. Look for entries related to BlockToolbar, GeneralHtmlSupport, or HtmlEmbed.

4. Test for Vulnerability: While it's not recommended to attempt actual exploitation, you can create a simple test case with potentially unsafe HTML content to see if it gets properly sanitized by your CKEditor instance. Always perform such tests in a safe, isolated environment.

5. Consult with Security Teams: If you're unsure about your configuration or the potential impact, consult with your organization's security team or a qualified web security professional for a thorough assessment.

Remember, even if your current configuration is not vulnerable, it's crucial to update to the patched version to prevent potential future issues if your configuration changes.

How to Fix CVE-2024-45613

To address the CVE-2024-45613 vulnerability in your CKEditor 5 implementation, follow these steps:

npm update ckeditor5 ckeditor5-clipboard

Or

yarn upgrade ckeditor5 ckeditor5-clipboard

2. Apply the Workaround (if immediate update is not possible): If you cannot immediately update to the patched version, you can implement a temporary workaround by disabling the Block Toolbar plugin. This will prevent the vulnerability from being exploited, but it may impact the functionality of your editor. To disable the Block Toolbar plugin, modify your CKEditor configuration:

ClassicEditor
    .create( document.querySelector( '#editor' ), {
        // Remove or comment out the BlockToolbar plugin
        // plugins: [ ..., BlockToolbar, ... ],
        // ...other configuration options...
    } )
    .then( /* ... */ )
    .catch( /* ... */ );

3. Review and Adjust Plugin Usage: After updating, review your use of the General HTML Support and HTML Embed plugins. If these features are not critical for your application, consider disabling them or configuring them more restrictively to reduce the attack surface.

4. Implement Content Security Policy (CSP): While not specific to this vulnerability, implementing a strong Content Security Policy can provide an additional layer of protection against XSS attacks. Configure your CSP headers to restrict the sources of executable scripts and other resources.

5. Perform Security Testing: After applying the fix or workaround, conduct thorough security testing of your CKEditor implementation to ensure the vulnerability has been properly mitigated and no other security issues are present.

6. Monitor for Future Updates: Stay informed about future security updates for CKEditor 5 by following their official channels, including the GitHub repository and security advisories.

7. Educate Development Team: Use this incident as an opportunity to educate your development team about the importance of prompt security updates and the risks associated with XSS vulnerabilities.

If you have any questions or concerns about this vulnerability or need assistance in securing your CKEditor 5 implementation, don't hesitate to reach out to the CKEditor security team at security@cksource.com or consult with a qualified web security professional.

We hope this post helps explores the details of CVE-2024-45613, its potential impact, affected versions, and most importantly - how to detect and mitigate this security risk in your CKEditor 5 implementations. Stay secure, stay updated, and continue to prioritize the safety of your users and their data. Thanks for reading this post. Please share this post and help secure the digital world.Visit our website thesecmaster.com, and our social media page on Facebook, LinkedIn, Twitter, Telegram, Tumblr, Medium, and Instagram and subscribe to receive updates like this

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