CVE-2025-39429: Széchenyi 2020 Logo Path Traversal Flaw

CVE-2025-39429 Overview

CVE-2025-39429 is a Local File Inclusion (LFI) vulnerability affecting the Széchenyi 2020 Logo WordPress plugin developed by Földesi, Mihály. This vulnerability stems from improper control of filename parameters used in PHP include/require statements, allowing attackers to include arbitrary local files from the server's filesystem.

The vulnerability is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program), which describes scenarios where user-supplied input is not properly sanitized before being used in file inclusion operations. Successful exploitation could allow attackers to read sensitive configuration files, access database credentials, or potentially achieve code execution by including files containing malicious PHP code.

Critical Impact

Attackers can leverage this Local File Inclusion vulnerability to read sensitive server files, potentially exposing credentials, configuration data, and enabling further exploitation of the WordPress installation.

Affected Products

• Széchenyi 2020 Logo WordPress Plugin versions through 1.1
• WordPress installations running vulnerable plugin versions
• Web servers hosting affected WordPress sites

Discovery Timeline

• 2025-04-17 - CVE-2025-39429 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2025-39429

Vulnerability Analysis

This vulnerability exists due to insufficient input validation in the Széchenyi 2020 Logo WordPress plugin. The plugin fails to properly sanitize user-controlled input before passing it to PHP's include() or require() functions, creating a Local File Inclusion (LFI) attack surface.

When exploited, an attacker can manipulate file path parameters to traverse directories and include arbitrary files from the local filesystem. This type of vulnerability is particularly dangerous in WordPress environments where sensitive files such as wp-config.php contain database credentials and authentication keys.

The attack can be escalated beyond simple file disclosure. If an attacker can inject PHP code into any file on the system (such as log files via log poisoning, or uploaded files), they can achieve remote code execution by including that file through this LFI vulnerability.

Root Cause

The root cause of CVE-2025-39429 is the lack of proper input sanitization and validation before file inclusion operations. The plugin accepts user-controlled input for file paths without implementing necessary security controls such as:

• Basename extraction to prevent directory traversal
• Whitelist validation of allowed files
• Proper canonicalization of file paths
• Removal of path traversal sequences (../, ..\\)

Attack Vector

The attack vector involves manipulating HTTP request parameters that are subsequently used in PHP file inclusion statements. An attacker crafts malicious requests containing directory traversal sequences to escape the intended directory and access sensitive files elsewhere on the filesystem.

Typical exploitation targets include:

• /etc/passwd for system user enumeration
• wp-config.php for database credentials
• Log files for log poisoning attacks
• Session files for session hijacking

The vulnerability can be exploited without authentication, making it particularly severe. Attackers can remotely send crafted requests to the vulnerable plugin endpoint, with the server processing the malicious file path and returning the contents of sensitive files.

Detection Methods for CVE-2025-39429

Indicators of Compromise

• Unusual HTTP requests containing directory traversal patterns (../, ..%2f, %2e%2e/) targeting the szechenyi-2020-logo plugin
• Access log entries showing attempts to read sensitive files like /etc/passwd or wp-config.php
• Web application firewall (WAF) alerts for path traversal attempts
• Unexpected plugin behavior or file access patterns in PHP error logs

Detection Strategies

• Deploy web application firewall rules to detect and block path traversal patterns in HTTP requests
• Monitor access logs for requests to the szechenyi-2020-logo plugin containing suspicious path characters
• Implement file integrity monitoring on critical WordPress files including wp-config.php
• Enable PHP error logging to capture include/require failures that may indicate exploitation attempts

Monitoring Recommendations

• Configure real-time alerting for path traversal signatures in HTTP request parameters
• Monitor server file access logs for reads of sensitive system files from the web server process
• Implement WordPress security plugins that detect LFI exploitation patterns
• Review web server logs regularly for anomalous access patterns to plugin directories

How to Mitigate CVE-2025-39429

Immediate Actions Required

• Deactivate and remove the Széchenyi 2020 Logo plugin immediately if running version 1.1 or earlier
• Audit WordPress installations for any signs of compromise or unauthorized file access
• Review web server access logs for historical exploitation attempts
• Implement web application firewall rules to block path traversal patterns

Patch Information

As of the last NVD update, users should check the Patchstack Vulnerability Report for the latest patch information and remediation guidance. If no patched version is available, consider removing the plugin entirely and seeking alternative solutions.

Workarounds

• Disable the Széchenyi 2020 Logo plugin until a security patch is released
• Implement server-side path filtering using .htaccess or nginx configuration rules to block traversal sequences
• Deploy a web application firewall with LFI/path traversal detection capabilities
• Restrict PHP's open_basedir directive to limit accessible file paths

# Apache .htaccess configuration to block path traversal
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./|\.\.\\) [NC,OR]
RewriteCond %{QUERY_STRING} (boot\.ini|etc/passwd|self/environ) [NC]
RewriteRule .* - [F,L]

# PHP configuration hardening in php.ini
# Restrict file access to WordPress directory
open_basedir = /var/www/html/wordpress/

# Disable dangerous functions
disable_functions = exec,passthru,shell_exec,system,proc_open,popen