CVE-2025-48106: Clanora File Upload Vulnerability

CVE-2025-48106 Overview

CVE-2025-48106 is an Unrestricted Upload of File with Dangerous Type vulnerability affecting the CMSSuperHeroes Clanora WordPress theme. This vulnerability allows attackers to upload malicious files to vulnerable WordPress installations, potentially leading to complete site compromise through remote code execution.

The vulnerability is classified under CWE-434 (Unrestricted Upload of File with Dangerous Type), which represents one of the most dangerous web application security flaws. Attackers can exploit this weakness to upload web shells, backdoors, or other malicious scripts that execute on the server with the privileges of the web application.

Critical Impact

This vulnerability allows unauthenticated remote attackers to upload arbitrary files including executable PHP scripts, enabling complete WordPress site takeover and server compromise.

Affected Products

• CMSSuperHeroes Clanora WordPress Theme versions prior to 1.3.1
• WordPress installations using vulnerable Clanora theme versions

Discovery Timeline

• 2025-10-22 - CVE-2025-48106 published to NVD
• 2026-01-20 - Last updated in NVD database

Technical Details for CVE-2025-48106

Vulnerability Analysis

The Clanora WordPress theme contains an unrestricted file upload vulnerability that fails to properly validate uploaded file types. This flaw exists in the theme's file upload handling functionality, which does not adequately restrict the types of files that can be uploaded by users.

The vulnerability is exploitable over the network without requiring any prior authentication or user interaction, making it particularly dangerous for publicly accessible WordPress sites. When successfully exploited, an attacker can upload PHP web shells or other malicious scripts that execute server-side, granting the attacker complete control over the WordPress installation and potentially the underlying server.

The scope of this vulnerability extends beyond the vulnerable component itself, as a successful attack can affect the confidentiality, integrity, and availability of other resources on the system. This includes access to sensitive database credentials, user data, and the ability to pivot to other applications hosted on the same server.

Root Cause

The root cause of CVE-2025-48106 is insufficient file type validation in the Clanora theme's upload functionality. The vulnerable code fails to properly verify that uploaded files match expected safe file types such as images. Instead, attackers can bypass any client-side restrictions and upload files with dangerous extensions like .php, .phtml, or other executable file types.

Common issues leading to this vulnerability include:

• Reliance on client-side validation only
• Checking only the MIME type header which can be easily spoofed
• Failure to validate file contents against their declared type
• Missing server-side file extension whitelisting

Attack Vector

An attacker exploits this vulnerability by sending a crafted HTTP request to the vulnerable upload endpoint in the Clanora theme. The attack involves:

1. Identifying a WordPress site running a vulnerable version of the Clanora theme
2. Locating the unrestricted file upload endpoint within the theme
3. Crafting a malicious PHP file (web shell) disguised or uploaded directly
4. Sending a POST request with the malicious file to bypass any inadequate validation
5. Accessing the uploaded file via the web server to execute arbitrary commands

The attacker modifies the Content-Type header to appear as a legitimate image while uploading a PHP script containing malicious code. Once uploaded, the attacker navigates to the uploaded file's URL to execute the payload, gaining remote code execution on the server.

Detection Methods for CVE-2025-48106

Indicators of Compromise

• Unexpected PHP files appearing in WordPress upload directories (wp-content/uploads/)
• Web shell files with suspicious names or obfuscated content in theme directories
• Unusual outbound network connections from the web server
• Access logs showing requests to recently uploaded PHP files in non-standard locations
• Modified or new files in the Clanora theme directory with recent timestamps

Detection Strategies

• Monitor WordPress upload directories for new PHP or executable file types
• Implement file integrity monitoring on WordPress theme and upload directories
• Configure web application firewall (WAF) rules to detect file upload attacks
• Review web server access logs for suspicious POST requests to theme endpoints
• Deploy endpoint detection solutions to identify web shell activity patterns

Monitoring Recommendations

• Enable detailed logging for all file upload operations in WordPress
• Configure alerts for any new executable file creation in web directories
• Implement real-time monitoring of process execution by the web server user
• Monitor for anomalous command execution patterns from web application processes
• Set up baseline comparisons for theme file checksums and alert on deviations

How to Mitigate CVE-2025-48106

Immediate Actions Required

• Update the Clanora WordPress theme to version 1.3.1 or later immediately
• Audit WordPress upload directories for any suspicious or unexpected files
• Review web server logs for signs of exploitation attempts
• Temporarily disable the Clanora theme if immediate patching is not possible
• Conduct a full malware scan of the WordPress installation

Patch Information

CMSSuperHeroes has addressed this vulnerability in Clanora theme version 1.3.1. Administrators should update to this version or later to remediate the vulnerability. For detailed patch information, refer to the Patchstack WordPress Vulnerability Report.

To update the theme:

1. Log into the WordPress admin dashboard
2. Navigate to Appearance > Themes
3. Update the Clanora theme to version 1.3.1 or later
4. Verify the update was successful

Workarounds

• Implement web application firewall rules to block malicious file uploads
• Restrict file upload functionality at the web server level using .htaccess or server configuration
• Configure the server to prevent PHP execution in upload directories
• Use WordPress security plugins that provide upload scanning and hardening
• Consider temporarily switching to an alternative theme until patching is complete

# Prevent PHP execution in uploads directory via .htaccess
# Add this to wp-content/uploads/.htaccess

<FilesMatch "\.(?:php|phtml|php3|php4|php5|php7|phps)$">
    Order Deny,Allow
    Deny from all
</FilesMatch>

# Alternative using Apache mod_php
<IfModule mod_php.c>
    php_flag engine off
</IfModule>