CVE-2024-3806: Porto WordPress Theme RCE Vulnerability

CVE-2024-3806 Overview

The Porto theme for WordPress contains a critical Local File Inclusion (LFI) vulnerability in all versions up to and including 7.1.0. The vulnerability exists in the porto_ajax_posts function, which fails to properly sanitize user-supplied input before including files on the server. This security flaw enables unauthenticated attackers to include and execute arbitrary files on the server, potentially allowing the execution of any PHP code contained within those files.

Critical Impact

Unauthenticated attackers can exploit this vulnerability to bypass access controls, obtain sensitive data, or achieve remote code execution by uploading and including malicious PHP files on vulnerable WordPress installations.

Affected Products

• Porto WordPress Theme versions up to and including 7.1.0
• WordPress installations using vulnerable Porto theme versions
• E-commerce websites built with the Porto responsive WordPress theme

Discovery Timeline

• May 14, 2024 - CVE-2024-3806 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2024-3806

Vulnerability Analysis

This Local File Inclusion vulnerability allows unauthenticated attackers to exploit the porto_ajax_posts function within the Porto WordPress theme. The function processes user-supplied input without adequate validation or sanitization, enabling malicious actors to manipulate file path parameters and include arbitrary local files from the server's filesystem.

When exploited, attackers can leverage this vulnerability to read sensitive configuration files such as wp-config.php, which contains database credentials and authentication keys. More critically, if an attacker can upload a file with PHP code (even with a non-PHP extension in some configurations), they can then include that file through this vulnerability to achieve arbitrary code execution on the server.

The attack requires no authentication, meaning any remote attacker can target vulnerable installations over the network without requiring valid credentials or user interaction.

Root Cause

The root cause of this vulnerability is improper input validation in the porto_ajax_posts function. The function accepts user-controlled parameters that specify file paths without implementing proper sanitization or allowlist validation. This allows attackers to traverse directory structures and include files outside the intended scope, ultimately enabling arbitrary file inclusion and code execution.

Attack Vector

The vulnerability is exploited remotely over the network through crafted HTTP requests to the vulnerable AJAX endpoint. Attackers send malicious requests containing path traversal sequences or controlled file paths to the porto_ajax_posts function. Since the function processes these inputs without proper validation, the attacker-specified files are included and executed by the PHP interpreter.

The attack chain typically involves:

1. Identifying a WordPress site running a vulnerable Porto theme version
2. Crafting malicious requests targeting the porto_ajax_posts AJAX handler
3. Using path traversal techniques to include sensitive files or previously uploaded malicious PHP content
4. Achieving code execution through the included PHP file

The vulnerability can be exploited without authentication, making it particularly dangerous for internet-facing WordPress installations. For detailed technical analysis, refer to the Wordfence Vulnerability Report.

Detection Methods for CVE-2024-3806

Indicators of Compromise

• Suspicious HTTP requests to WordPress AJAX endpoints containing path traversal sequences such as ../ patterns
• Unexpected file access attempts in web server logs targeting configuration files like wp-config.php
• Unusual PHP file uploads or modifications in the WordPress uploads directory
• Web server error logs showing file inclusion attempts from unexpected directories

Detection Strategies

• Monitor web application firewall (WAF) logs for requests containing Local File Inclusion patterns targeting the Porto theme AJAX handlers
• Implement file integrity monitoring to detect unauthorized modifications to theme files and WordPress core
• Review access logs for anomalous requests to admin-ajax.php with suspicious action parameters related to Porto functions
• Deploy intrusion detection signatures that identify path traversal patterns in HTTP request parameters

Monitoring Recommendations

• Enable verbose logging on web servers to capture full request URIs and POST data for forensic analysis
• Configure real-time alerting for any access attempts to sensitive files like wp-config.php through non-standard paths
• Monitor for new file creation in WordPress writable directories that could indicate uploaded malicious payloads
• Implement SentinelOne Singularity platform for endpoint detection and response coverage on web servers hosting WordPress installations

How to Mitigate CVE-2024-3806

Immediate Actions Required

• Update the Porto WordPress theme to a version newer than 7.1.0 that addresses this vulnerability
• Implement Web Application Firewall (WAF) rules to block requests containing path traversal patterns
• Review WordPress installations for any signs of compromise, including unexpected files or modified content
• Restrict file upload capabilities and validate uploaded file types at the server level

Patch Information

Users should update the Porto theme to the latest available version through the ThemeForest Product Page. The vendor has released security updates addressing this Local File Inclusion vulnerability. Organizations should prioritize this update given the critical severity and the unauthenticated nature of the attack vector.

Workarounds

• Temporarily disable the Porto theme and switch to a default WordPress theme until the update can be applied
• Implement strict WAF rules to filter and block requests containing path traversal characters (../, ..%2f, etc.) targeting AJAX endpoints
• Restrict direct access to admin-ajax.php from untrusted sources using server-level access controls where feasible
• Enable WordPress debug logging temporarily to monitor for exploitation attempts while implementing permanent fixes

# Example .htaccess rules to help mitigate LFI attempts
# Add to WordPress root .htaccess file

# Block common path traversal patterns in query strings
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./|\.\.%2f) [NC,OR]
RewriteCond %{QUERY_STRING} (etc/passwd|proc/self) [NC]
RewriteRule .* - [F,L]

# Additional protection for wp-config.php
<Files wp-config.php>
    Order deny,allow
    Deny from all
</Files>