CVE-2025-14842: WordPress Contact Form 7 RCE Vulnerability

CVE-2025-14842 Overview

The Drag and Drop Multiple File Upload – Contact Form 7 plugin for WordPress contains an unrestricted file upload vulnerability (CWE-434) that allows unauthenticated attackers to upload potentially dangerous .phar and .svg files. The plugin fails to properly block these file types in its upload validation logic, creating pathways for both remote code execution and stored cross-site scripting attacks.

This vulnerability affects all versions of the plugin up to and including version 1.3.9.2. When exploited, attackers can upload .phar files containing malicious PHP code which may execute directly on servers configured to process .phar files as PHP. Additionally, malicious .svg files can be uploaded to achieve Stored Cross-Site Scripting (XSS) attacks under certain circumstances.

Critical Impact

Unauthenticated attackers can upload arbitrary .phar or .svg files, potentially achieving remote code execution on vulnerable server configurations or executing stored XSS attacks against site visitors.

Affected Products

• Drag and Drop Multiple File Upload – Contact Form 7 plugin for WordPress versions up to and including 1.3.9.2
• WordPress sites using Contact Form 7 with the vulnerable upload plugin
• Web servers configured to execute .phar files as PHP (for RCE impact)

Discovery Timeline

• 2026-01-07 - CVE-2025-14842 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2025-14842

Vulnerability Analysis

This vulnerability stems from insufficient file type validation in the Drag and Drop Multiple File Upload plugin for Contact Form 7. The plugin maintains an allowlist or blocklist of file extensions but fails to include .phar (PHP Archive) and .svg (Scalable Vector Graphics) files in its dangerous file type restrictions.

The attack surface is particularly concerning because it can be exploited by unauthenticated users. Any visitor to a WordPress site with an exposed Contact Form 7 form using this plugin can attempt to upload malicious files. The vulnerability requires user interaction in the sense that an administrator or user must access the uploaded SVG file for XSS to trigger, though server-side code execution via .phar files may occur through direct file access depending on server configuration.

The scope is classified as "Changed" meaning successful exploitation can impact resources beyond the vulnerable component itself—for example, compromising the underlying web server or affecting other users who view uploaded SVG content.

Root Cause

The root cause of this vulnerability is incomplete input validation in the file upload handling functions. Specifically, the plugin's upload validation logic in dnd-upload-cf7.php does not recognize .phar and .svg as dangerous file types that should be blocked.

PHP Archive (.phar) files are a legitimate PHP packaging format but can contain executable PHP code. When a web server is configured to handle .phar files through the PHP interpreter, uploading such files effectively allows arbitrary PHP code execution.

SVG files, while typically used for vector graphics, are XML-based and can contain embedded JavaScript code. When rendered in a browser context, this JavaScript executes, enabling stored XSS attacks.

Attack Vector

The attack is network-based and requires no authentication. An attacker can exploit this vulnerability through the following general approach:

1. Identify Target: Locate a WordPress site running the vulnerable Drag and Drop Multiple File Upload plugin with an exposed Contact Form 7 form
2. Craft Malicious File: Create a .phar file containing malicious PHP code or an .svg file with embedded JavaScript
3. Upload File: Submit the malicious file through the contact form's file upload functionality
4. Trigger Execution: For .phar files, directly access the uploaded file path (if server executes .phar as PHP); for .svg files, wait for a user/admin to view the file or embed it in a page context

The vulnerability mechanism involves bypassing file type restrictions. Technical details can be found in the WordPress File Upload Code and the Wordfence Vulnerability Report.

Detection Methods for CVE-2025-14842

Indicators of Compromise

• Presence of .phar or .svg files in WordPress upload directories, particularly in Contact Form 7 upload locations
• Unexpected PHP Archive files in /wp-content/uploads/ or plugin-specific upload directories
• SVG files containing <script> tags, JavaScript event handlers, or javascript: URIs
• Web server access logs showing direct requests to .phar files in upload directories

Detection Strategies

• Monitor file upload events for .phar and .svg file extensions in WordPress upload directories
• Implement file integrity monitoring (FIM) to detect new executable file types in upload paths
• Scan uploaded SVG files for JavaScript content or malicious XML entities
• Review web server logs for unusual access patterns to upload directories

Monitoring Recommendations

• Configure web application firewall (WAF) rules to block .phar file uploads and inspect SVG content
• Enable logging for all file upload operations in WordPress and Contact Form 7
• Set up alerts for new files with executable extensions appearing in upload directories
• Implement SentinelOne endpoint detection to identify PHP code execution from unexpected file locations

How to Mitigate CVE-2025-14842

Immediate Actions Required

• Update the Drag and Drop Multiple File Upload – Contact Form 7 plugin to the latest patched version immediately
• Audit existing upload directories for any .phar or .svg files that may have been maliciously uploaded
• Configure web server to prevent execution of .phar files by removing the handler or blocking direct access
• Temporarily disable file uploads in Contact Form 7 if immediate patching is not possible

Patch Information

A security patch is available through the WordPress Plugin Changeset. The fix adds .phar and .svg to the list of blocked file extensions, preventing these dangerous file types from being uploaded through the plugin.

To update, navigate to the WordPress admin dashboard, go to Plugins, and update the "Drag and Drop Multiple File Upload – Contact Form 7" plugin to the latest available version. Verify the update by checking the plugin version number exceeds 1.3.9.2.

Workarounds

• Add .phar and .svg to the blocked file extensions list in the plugin settings if configurable
• Configure Apache/Nginx to deny direct access to upload directories or block .phar execution entirely
• Use a Web Application Firewall (WAF) to block file uploads with .phar or .svg extensions
• Implement server-side file type validation using MIME type checking in addition to extension filtering

# Apache configuration to block .phar execution in uploads directory
<Directory "/var/www/html/wp-content/uploads">
    <FilesMatch "\.phar$">
        Require all denied
    </FilesMatch>
    php_flag engine off
</Directory>