CVE-2022-41634: Cross-Site Request Forgery (CSRF) Vulnerability Discovered in Media Library Folders Plugin (<= 7.1.1) on WordPress - Exploit Details, Original References, and Mitigation Steps

A recent security advisory has disclosed a Cross-Site Request Forgery (CSRF) vulnerability, labeled as CVE-2022-41634, affecting the popular Media Library Folders plugin (version 7.1.1 and lower) for WordPress. If exploited, this vulnerability allows an attacker to manipulate data on a target website, potentially causing data loss, unauthorized access, or other security breaches. In this post, we will explain the details surrounding this vulnerability, provide code snippets illustrating the issue, and offer guidance on mitigating the risk.

Context

Media Library Folders (MLF) is a widely used plugin for WordPress that provides advanced media management capabilities, including organizing, renaming, and moving media files within complex folder hierarchies. Because the plugin operates with high levels of permission, exploiting the CSRF vulnerability can result in significant unintended consequences for the targeted site.

Original References

The vulnerability was initially reported by independent security researchers, whose findings were subsequently confirmed and analyzed by WPScan Vulnerability Database:

- WPScan Vulnerability Reference: https://wpscan.com/vulnerability/ffa12629-1b7f-4a74-aaf2-26031dd6f9dd

Exploit Details

The CSRF vulnerability discovered in MLF plugin (<= 7.1.1) enables a malicious actor to forge web requests on behalf of an authenticated user, often an administrator, to perform various actions without the user's consent. For instance, deleting or moving a media file without permission, potentially causing data loss or disruption on the target website.

Below is a simplified code snippet for illustration, which demonstrates the lack of token validation when the plugin processes the AJAX request for deleting a file:

// Simplified vulnerable code from - media-library-folders.php
function mlf_delete_file_callback() {
   $ajax_nonce = $_POST['mlf_nonce'];
   // There should be a nonce validation here, such as:
   // if ( ! wp_verify_nonce( $ajax_nonce, 'media-library-folders' ) ) {
   //   die( 'Invalid security token' ); 
   // }
   $file =ABSPATH . $_POST['folder'] . "/" . $_POST['file'];
   unlink($file);
   die('File deleted');
}

As illustrated above, the lack of nonce validation (wp_verify_nonce) means that MLF is unable to confirm whether the incoming request is legitimate or crafted by an attacker.

Mitigation Steps

To ensure the security of your WordPress site employing the vulnerable version of the MLF plugin, below are the recommended steps:

1. Update the Media Library Folders plugin as soon as a patch or newer, secured version becomes available. Stay informed regarding any updates from the plugin developer by following their announcements, blog, or support forum.

2. Limit user permissions on your site, particularly for any user with the capacity to interact or modify the media library.

3. Implement and enforce strong password policies for all users with access to the media library, as well as any administrator accounts.

4. Use security plugins or a Web Application Firewall (WAF) to monitor and restrict unauthorized access attempts to your site.

In conclusion, CVE-2022-41634 is a critical vulnerability affecting the Media Library Folders plugin (<= 7.1.1) for WordPress, which can lead to unwanted consequences like data loss or unauthorized access. By staying informed, updating the plugin as needed, and following the recommended mitigation steps above, you can help ensure the security of your website and its users.

Timeline

Published on: 11/18/2022 23:15:00 UTC
Last modified on: 11/23/2022 18:05:00 UTC