CVE-2024-31351: Copymatic Path Traversal Vulnerability

CVE-2024-31351 Overview

CVE-2024-31351 is an Unrestricted Upload of File with Dangerous Type vulnerability (CWE-434) in the Copymatic – AI Content Writer & Generator WordPress plugin. This vulnerability allows unauthenticated attackers to upload arbitrary files, including malicious PHP scripts, to vulnerable WordPress installations. The flaw exists in versions from n/a through 1.6 of the Copymatic plugin.

Critical Impact

Unauthenticated attackers can upload malicious files to WordPress servers, potentially leading to complete site compromise, remote code execution, and full server takeover.

Affected Products

• Copymatic – AI Content Writer & Generator plugin for WordPress (versions through 1.6)
• WordPress installations using the vulnerable Copymatic plugin
• Any website with the Copymatic plugin installed without proper file upload restrictions

Discovery Timeline

• 2024-05-17 - CVE-2024-31351 published to NVD
• 2025-04-18 - Last updated in NVD database

Technical Details for CVE-2024-31351

Vulnerability Analysis

This vulnerability stems from inadequate file upload validation within the Copymatic WordPress plugin. The plugin fails to properly restrict the types of files that can be uploaded through its functionality. Without proper validation of file extensions, MIME types, or file content, attackers can bypass intended security controls and upload executable files such as PHP web shells.

The attack can be executed remotely over the network without requiring any authentication or user interaction. This makes exploitation straightforward for attackers, as they can target any publicly accessible WordPress site running the vulnerable plugin version. Successful exploitation grants attackers the ability to execute arbitrary code on the server, potentially leading to complete compromise of confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of CVE-2024-31351 is the lack of proper file type validation in the Copymatic plugin's upload functionality. The plugin does not implement adequate checks to verify that uploaded files are of expected and safe types. This includes missing validation for:

• File extension whitelisting
• MIME type verification
• File content inspection (magic bytes)
• Proper sanitization of file names

Without these controls, the application accepts any file type uploaded by users, including executable scripts that can be used to compromise the web server.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or privileges. An attacker can exploit this vulnerability by:

1. Identifying a WordPress site running a vulnerable version of the Copymatic plugin
2. Crafting a malicious file (such as a PHP web shell) to upload
3. Submitting the malicious file through the plugin's unprotected upload endpoint
4. Accessing the uploaded file directly to execute arbitrary commands on the server

The vulnerability enables arbitrary file upload, which typically leads to remote code execution. Once a web shell or similar malicious script is uploaded, the attacker can execute system commands, steal sensitive data, modify website content, or pivot to attack other systems on the network. For detailed technical information, see the Patchstack Vulnerability Report.

Detection Methods for CVE-2024-31351

Indicators of Compromise

• Unexpected PHP or executable files appearing in WordPress upload directories or plugin folders
• Web server access logs showing requests to unusual file paths within the Copymatic plugin directory
• Newly created files with suspicious names or obfuscated content in the wp-content/uploads/ directory
• Unusual outbound network connections from the web server indicating potential command and control activity

Detection Strategies

• Monitor WordPress file system integrity for unauthorized new files, especially in upload directories and plugin folders
• Implement web application firewall (WAF) rules to detect and block attempts to upload executable file types
• Review web server access logs for POST requests targeting Copymatic plugin endpoints with file upload payloads
• Deploy endpoint detection tools to identify web shell artifacts and suspicious PHP file execution patterns

Monitoring Recommendations

• Enable file integrity monitoring (FIM) on WordPress installations to detect unauthorized file changes
• Configure alerts for new files created in web-accessible directories with executable extensions
• Monitor web server process execution for anomalous child processes spawned by PHP
• Implement logging and alerting for failed and successful file upload attempts to WordPress sites

How to Mitigate CVE-2024-31351

Immediate Actions Required

• Update the Copymatic plugin to the latest patched version immediately
• Audit WordPress file system for any suspicious or unexpected files that may have been uploaded
• If a patch is not yet available, consider temporarily disabling or removing the Copymatic plugin
• Review web server logs for any signs of exploitation attempts or successful compromises
• Reset credentials and API keys if compromise is suspected

Patch Information

Organizations should update the Copymatic – AI Content Writer & Generator plugin to a version newer than 1.6 that addresses this vulnerability. Check the WordPress plugin repository or the Patchstack Vulnerability Report for the latest security updates and patch availability.

Workarounds

• Temporarily deactivate and remove the Copymatic plugin until a patched version is available
• Implement web application firewall rules to block file upload requests to vulnerable plugin endpoints
• Restrict upload file types at the web server level using configuration directives
• Apply the principle of least privilege to web server directories to prevent execution of uploaded files

# Apache configuration to prevent PHP execution in uploads directory
<Directory "/var/www/html/wp-content/uploads">
    <FilesMatch "\.php$">
        Require all denied
    </FilesMatch>
</Directory>