CVE-2026-25413: WPBookit Pro File Upload RCE Vulnerability

CVE-2026-25413 Overview

CVE-2026-25413 is an Unrestricted Upload of File with Dangerous Type vulnerability (CWE-434) affecting the WPBookit Pro WordPress plugin developed by iqonicdesign. This vulnerability allows attackers to upload malicious files to vulnerable WordPress installations, potentially leading to remote code execution, website defacement, or complete server compromise.

Critical Impact

Attackers can upload arbitrary files including web shells and malicious scripts, potentially gaining complete control over the affected WordPress site and underlying server.

Affected Products

• WPBookit Pro WordPress Plugin versions up to and including 1.6.18
• WordPress installations running vulnerable versions of the wpbookit-pro plugin

Discovery Timeline

• 2026-03-25 - CVE-2026-25413 published to NVD
• 2026-03-25 - Last updated in NVD database

Technical Details for CVE-2026-25413

Vulnerability Analysis

This vulnerability stems from improper validation of uploaded file types in the WPBookit Pro plugin. The plugin fails to adequately verify that uploaded files conform to expected safe file types, allowing attackers to bypass security controls and upload files with dangerous extensions such as .php, .phtml, or other executable formats.

When a malicious file is successfully uploaded, it can be accessed directly through the web server, enabling immediate code execution in the context of the web application. This type of vulnerability is particularly dangerous in WordPress environments where plugins often have broad access to the file system and database.

Root Cause

The root cause of CVE-2026-25413 is the absence of proper server-side file type validation in the WPBookit Pro plugin's file upload functionality. The vulnerability exists because:

1. The plugin does not properly validate file extensions against a whitelist of allowed types
2. MIME type validation may be missing or easily bypassed through content-type manipulation
3. Uploaded files may be stored in publicly accessible directories without proper access controls

Attack Vector

An attacker can exploit this vulnerability by crafting a malicious upload request to the WPBookit Pro plugin endpoints. The attack typically follows these steps:

1. Identify a WordPress installation running a vulnerable version of WPBookit Pro
2. Craft a malicious PHP file disguised or uploaded directly through the vulnerable endpoint
3. Submit the file through the plugin's upload functionality
4. Access the uploaded malicious file directly via the web browser
5. Execute arbitrary commands on the server through the uploaded web shell

The vulnerability requires network access to the target WordPress installation. Depending on the specific endpoint affected, the attack may require authentication or may be exploitable without any credentials.

Detection Methods for CVE-2026-25413

Indicators of Compromise

• Unexpected PHP or script files appearing in WordPress upload directories (e.g., wp-content/uploads/)
• Web shells or backdoor files with suspicious names or obfuscated content
• Unusual file types in directories managed by the WPBookit Pro plugin
• Anomalous outbound network connections from the web server
• Unexpected user accounts or privilege changes in WordPress

Detection Strategies

• Monitor file system changes in WordPress upload directories for newly created executable files
• Implement file integrity monitoring (FIM) to detect unauthorized file modifications
• Review web server access logs for requests to unusual file paths in upload directories
• Deploy web application firewall (WAF) rules to detect malicious file upload attempts
• Use WordPress security plugins to scan for known web shells and malicious code patterns

Monitoring Recommendations

• Enable detailed logging for all file upload operations in WordPress
• Configure alerts for new file creation events in sensitive directories
• Implement real-time malware scanning for uploaded files
• Monitor for POST requests to WPBookit Pro endpoints with suspicious file attachments

How to Mitigate CVE-2026-25413

Immediate Actions Required

• Update WPBookit Pro to a patched version as soon as one becomes available from iqonicdesign
• If no patch is available, consider temporarily disabling the WPBookit Pro plugin
• Audit upload directories for any suspicious or unexpected files
• Implement web application firewall rules to block malicious file uploads
• Restrict file upload capabilities to authenticated and trusted users only

Patch Information

Security advisories and patch information for this vulnerability can be found at the Patchstack WordPress Vulnerability Database. Site administrators should monitor for updates from iqonicdesign and apply patches promptly when released.

Workarounds

• Disable file upload functionality in WPBookit Pro until a patch is available
• Implement server-level restrictions to prevent PHP execution in upload directories
• Use .htaccess rules to deny direct access to uploaded files
• Deploy a web application firewall (WAF) with rules targeting file upload attacks
• Restrict plugin access to authenticated administrative users only

# Apache .htaccess configuration to prevent PHP execution in uploads directory
# Place in wp-content/uploads/.htaccess

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

# Alternative: Disable PHP entirely in uploads
php_flag engine off