CVE-2024-51919: Fancy Product Designer File Upload Flaw

CVE-2024-51919 Overview

CVE-2024-51919 is an Unrestricted Upload of File with Dangerous Type vulnerability affecting the Fancy Product Designer WordPress plugin. This critical flaw allows attackers to upload arbitrary files with dangerous types to a vulnerable WordPress installation without authentication, potentially leading to complete site compromise and remote code execution.

Critical Impact

Unauthenticated attackers can upload malicious files to WordPress sites running vulnerable versions of Fancy Product Designer, enabling remote code execution and full server compromise.

Affected Products

• Fancy Product Designer WordPress Plugin versions through 6.4.3
• WordPress installations with vulnerable plugin versions

Discovery Timeline

• 2025-01-21 - CVE-2024-51919 published to NVD
• 2025-01-21 - Last updated in NVD database

Technical Details for CVE-2024-51919

Vulnerability Analysis

This vulnerability falls under CWE-434 (Unrestricted Upload of File with Dangerous Type), which occurs when the application fails to properly validate or restrict the types of files that users can upload. In the context of WordPress plugins like Fancy Product Designer, this typically manifests through file upload functionality that allows users to customize products with custom images or designs.

The vulnerability is particularly dangerous because it can be exploited without authentication. An attacker can craft a malicious file (such as a PHP web shell) disguised or uploaded directly through the plugin's upload mechanism. Once the malicious file is uploaded to the server, the attacker can execute arbitrary code by directly accessing the uploaded file.

The attack complexity is rated as high due to certain conditions that may need to be met for successful exploitation, but the potential impact spans confidentiality, integrity, and availability with scope change implications, meaning a successful exploit could affect resources beyond the vulnerable component.

Root Cause

The root cause of this vulnerability lies in insufficient file type validation within the Fancy Product Designer plugin's file upload functionality. The plugin fails to properly sanitize and validate uploaded files, allowing potentially dangerous file types (such as .php, .phtml, or other executable scripts) to be uploaded to the server's file system.

Common implementation mistakes that lead to this vulnerability include:

• Relying solely on client-side file type validation
• Checking only the file extension without validating the actual file content (MIME type)
• Insufficient allowlist/blocklist implementation for permitted file types
• Lack of proper file storage outside of the web-accessible directory

Attack Vector

The attack is network-based and can be executed remotely. An unauthenticated attacker targets the vulnerable file upload endpoint exposed by the Fancy Product Designer plugin. The attacker crafts a malicious file, typically a PHP web shell or similar executable script, and submits it through the plugin's upload functionality.

Upon successful upload, the malicious file is stored on the web server in a location accessible via HTTP. The attacker then navigates to the uploaded file's URL to execute the malicious code, gaining remote code execution capabilities on the server. This can lead to:

• Complete WordPress site takeover
• Database credential theft
• Lateral movement to other hosted sites
• Installation of backdoors for persistent access
• Defacement or data exfiltration

For detailed technical analysis, refer to the Patchstack Vulnerability Report.

Detection Methods for CVE-2024-51919

Indicators of Compromise

• Unexpected PHP files or scripts appearing in WordPress upload directories (typically wp-content/uploads/)
• Suspicious HTTP POST requests to Fancy Product Designer upload endpoints with non-image file types
• Web shells or backdoor files in plugin directories
• Unusual outbound network connections originating from the web server

Detection Strategies

• Monitor web server access logs for unusual POST requests to plugin endpoints, particularly those uploading non-standard file types
• Implement file integrity monitoring (FIM) to detect new or modified files in WordPress directories
• Deploy Web Application Firewall (WAF) rules to block uploads of executable file types
• Review server logs for execution of unexpected scripts in upload directories

Monitoring Recommendations

• Enable detailed logging for all file upload operations in WordPress
• Set up alerts for new files with executable extensions (.php, .phtml, .phar, etc.) created in upload directories
• Monitor for suspicious process spawning from web server processes
• Implement anomaly detection for unusual traffic patterns targeting WordPress plugin endpoints

How to Mitigate CVE-2024-51919

Immediate Actions Required

• Update Fancy Product Designer plugin to a version newer than 6.4.3 if a patched version is available
• If no patch is available, consider temporarily deactivating the Fancy Product Designer plugin until a fix is released
• Review WordPress uploads directory for any suspicious or unauthorized files
• Implement additional server-side file upload restrictions via .htaccess or web server configuration

Patch Information

Organizations using Fancy Product Designer should check for plugin updates through the WordPress admin dashboard or the plugin vendor's official website. Monitor the Patchstack Vulnerability Report for the latest remediation guidance.

Workarounds

• Implement .htaccess rules to prevent PHP execution in upload directories
• Configure Web Application Firewall (WAF) rules to block file uploads with dangerous extensions
• Use security plugins like Wordfence or Sucuri to add additional file upload validation layers
• Restrict file upload directory permissions to prevent script execution

# .htaccess configuration to prevent PHP execution in uploads directory
# Add to wp-content/uploads/.htaccess
<FilesMatch "\.(php|phtml|php3|php4|php5|php7|phps|phar|cgi|pl|py|exe|sh)$">
    Order Deny,Allow
    Deny from all
</FilesMatch>