CVE-2011-10041: Uploadify WordPress Plugin RCE Vulnerability

CVE-2011-10041 Overview

CVE-2011-10041 is a critical arbitrary file upload vulnerability affecting the Uploadify WordPress plugin versions up to and including 1.0. The vulnerability exists in the process_upload.php file due to missing file type validation, allowing unauthenticated remote attackers to upload arbitrary files to affected WordPress installations. This security flaw can lead to remote code execution when malicious executable content is uploaded to web-accessible locations.

Critical Impact

Unauthenticated attackers can upload malicious PHP files or web shells to WordPress sites, enabling complete server compromise and remote code execution without any authentication requirements.

Affected Products

• Uploadify WordPress Plugin version 1.0
• Uploadify WordPress Plugin versions prior to 1.0

Discovery Timeline

• 2026-01-15 - CVE CVE-2011-10041 published to NVD
• 2026-01-20 - Last updated in NVD database

Technical Details for CVE-2011-10041

Vulnerability Analysis

This vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type). The Uploadify plugin's process_upload.php script fails to implement proper file type validation before accepting and storing uploaded files. This architectural oversight allows any file type—including executable scripts like PHP files—to be uploaded directly to the web server without restriction.

The network-accessible attack vector combined with the absence of authentication requirements makes this vulnerability particularly dangerous. An attacker can exploit this flaw remotely without any prior access to the WordPress installation, user interaction, or special privileges.

Root Cause

The root cause of CVE-2011-10041 lies in the process_upload.php file's complete lack of file type validation logic. The script accepts incoming file uploads and writes them to the server filesystem without checking the file extension, MIME type, or content. This missing security control violates the principle of defense in depth and allows attackers to bypass intended restrictions on uploadable content types.

Attack Vector

The attack vector for this vulnerability is network-based, requiring no authentication or user interaction. An attacker can craft HTTP requests directly to the process_upload.php endpoint, uploading malicious files such as PHP web shells. Once uploaded to a web-accessible directory, these files can be executed by accessing them via HTTP, granting the attacker arbitrary code execution capabilities on the underlying server.

The exploitation process typically involves:

1. Identifying a WordPress installation with the vulnerable Uploadify plugin
2. Sending a crafted multipart POST request to process_upload.php with a malicious PHP payload
3. Locating the uploaded file in the uploads directory
4. Accessing the uploaded file via HTTP to trigger code execution

For technical details on the exploitation technique, refer to the Packet Storm advisory and the WPScan Vulnerability Report.

Detection Methods for CVE-2011-10041

Indicators of Compromise

• Unexpected PHP files or executable scripts appearing in WordPress upload directories
• Web server access logs showing POST requests to process_upload.php from unknown sources
• Suspicious files with obfuscated content or web shell signatures in plugin directories
• Anomalous outbound network connections from the web server process

Detection Strategies

• Monitor HTTP POST requests targeting /wp-content/plugins/uploadify/process_upload.php for suspicious file upload attempts
• Implement file integrity monitoring on WordPress installations to detect unauthorized file additions
• Deploy web application firewall (WAF) rules to block file upload requests containing executable content
• Review web server logs for patterns consistent with web shell deployment and callback activity

Monitoring Recommendations

• Enable detailed logging for all file upload operations on WordPress installations
• Configure alerts for new PHP file creation in upload directories or plugin folders
• Implement real-time file scanning for newly uploaded content to detect malicious payloads
• Monitor for reconnaissance activity targeting WordPress plugin endpoints

How to Mitigate CVE-2011-10041

Immediate Actions Required

• Remove or disable the Uploadify plugin immediately from all WordPress installations
• Audit upload directories for any suspicious or unexpected files that may have been uploaded
• Review web server logs for evidence of exploitation attempts targeting process_upload.php
• Consider scanning the server for web shells and other persistent backdoors

Patch Information

There is no known patch available for this vulnerability. The Uploadify WordPress plugin version 1.0 and earlier remain vulnerable. Organizations should remove this plugin entirely and migrate to a maintained file upload solution with proper security controls.

For additional vulnerability details, refer to:

• Wordfence Uploadify Vulnerability Overview
• VulnCheck Advisory on Uploadify
• Acunetix Web Vulnerability Analysis

Workarounds

• Block access to process_upload.php at the web server level using access control directives
• Implement strict file upload restrictions at the web server or WAF level to block executable file types
• Restrict access to WordPress plugin directories via IP allowlisting or authentication requirements

# Apache .htaccess configuration to block access to vulnerable script
<Files "process_upload.php">
    Order Allow,Deny
    Deny from all
</Files>

# Alternative: Block PHP execution in uploads directory
<Directory "/path/to/wordpress/wp-content/uploads">
    <FilesMatch "\.php$">
        Order Allow,Deny
        Deny from all
    </FilesMatch>
</Directory>