CVE-2025-14800: WordPress Redirection CF7 RCE Vulnerability

CVE-2025-14800 Overview

The Redirection for Contact Form 7 plugin for WordPress contains an arbitrary file upload vulnerability due to missing file type validation in the move_file_to_upload function. This critical flaw affects all versions up to and including 3.2.7, allowing unauthenticated attackers to copy arbitrary files to the affected site's server. When the PHP configuration setting allow_url_fopen is enabled, attackers can also upload remote files directly to the server, significantly expanding the attack surface.

Critical Impact

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

Affected Products

• Redirection for Contact Form 7 plugin for WordPress versions ≤ 3.2.7
• WordPress installations with the vulnerable plugin installed
• Servers with allow_url_fopen enabled are at increased risk for remote file upload attacks

Discovery Timeline

• 2025-12-21 - CVE-2025-14800 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-14800

Vulnerability Analysis

This vulnerability is classified as CWE-434 (Unrestricted Upload of File with Dangerous Type). The core issue stems from the move_file_to_upload function within the class-wpcf7r-save-files.php file failing to implement proper file type validation before processing uploaded files. This architectural weakness allows attackers to bypass intended security controls and upload files of any type to the WordPress server.

The vulnerability is particularly dangerous because it requires no authentication, meaning any remote attacker can exploit it without needing valid credentials. The attack can be conducted entirely over the network, though the exploitation complexity is considered higher due to specific conditions that must be met for successful compromise.

Root Cause

The root cause lies in the absence of file type validation logic within the move_file_to_upload function located at line 180 in class-wpcf7r-save-files.php. The function accepts file inputs without verifying whether the uploaded file matches an allowed list of safe file extensions or MIME types. This missing input validation is a fundamental security oversight that enables the arbitrary file upload attack vector.

When allow_url_fopen is set to On in the PHP configuration, the vulnerability becomes more severe as it allows the function to fetch and upload files from remote URLs, enabling Server-Side Request Forgery (SSRF) scenarios and remote file inclusion attacks.

Attack Vector

The attack is network-based and can be executed by unauthenticated users. An attacker can craft a malicious request targeting the vulnerable file upload functionality to copy arbitrary files to the server. The attack flow typically involves:

1. Identifying a WordPress installation running a vulnerable version of the Redirection for Contact Form 7 plugin
2. Crafting a request that exploits the move_file_to_upload function's lack of file type validation
3. Uploading a malicious PHP webshell or other executable file to the server
4. Accessing the uploaded file directly to execute arbitrary code

The vulnerability mechanism exploits the missing file type validation in the file handling logic. When processing file uploads, the plugin fails to check the extension or MIME type of the uploaded file against a whitelist of safe types. Attackers can leverage this to upload PHP files containing malicious code, which can then be executed by directly requesting the uploaded file's URL. For detailed technical analysis, refer to the WordPress Plugin Code Review and the Wordfence Vulnerability Report.

Detection Methods for CVE-2025-14800

Indicators of Compromise

• Unexpected PHP files appearing in WordPress upload directories (typically wp-content/uploads/)
• Web server logs showing requests to unusual PHP files in upload directories
• Presence of webshell indicators such as encoded eval(), base64_decode(), or system() calls in recently created files
• Unusual outbound network connections from the web server

Detection Strategies

• Monitor WordPress upload directories for new PHP files or files with double extensions (e.g., image.php.jpg)
• Implement Web Application Firewall (WAF) rules to detect and block file upload attempts with dangerous extensions
• Enable file integrity monitoring on the WordPress installation directory
• Review HTTP POST requests to Contact Form 7 endpoints for suspicious file content

Monitoring Recommendations

• Configure alerts for any new file creation in the wp-content/uploads/ directory tree
• Implement real-time log analysis for requests targeting the Redirection for Contact Form 7 plugin endpoints
• Deploy endpoint detection and response (EDR) solutions to monitor for webshell behavior patterns
• Regularly audit installed WordPress plugins and their versions against known vulnerability databases

How to Mitigate CVE-2025-14800

Immediate Actions Required

• Update the Redirection for Contact Form 7 plugin to a version newer than 3.2.7 immediately
• If updating is not immediately possible, deactivate the Redirection for Contact Form 7 plugin until a patch can be applied
• Set allow_url_fopen to Off in your PHP configuration to prevent remote file upload attacks
• Audit the WordPress upload directories for any suspicious files that may have been uploaded during the exposure window

Patch Information

The vulnerability has been addressed in versions newer than 3.2.7. Review the WordPress Plugin Change Log for details on the security fix. Administrators should update through the WordPress plugin management interface or by manually downloading and installing the latest version from the WordPress plugin repository.

Workarounds

• Disable the Redirection for Contact Form 7 plugin if updating is not immediately feasible
• Implement WAF rules to block file upload requests containing executable file extensions (.php, .phtml, .php5, etc.)
• Set allow_url_fopen = Off in php.ini to prevent remote file upload scenarios
• Configure web server rules to deny execution of PHP files in upload directories

# Apache .htaccess configuration to prevent PHP execution in uploads
# Add to wp-content/uploads/.htaccess
<FilesMatch "\.(?:php|phtml|php5|php7|phar)$">
    Require all denied
</FilesMatch>

# Nginx configuration to prevent PHP execution in uploads
# Add to server block
location ~* /wp-content/uploads/.*\.php$ {
    deny all;
}

# PHP configuration to disable remote file uploads
# Set in php.ini
allow_url_fopen = Off