CVE-2025-69398: ThemeREX Plank LFI Vulnerability

CVE-2025-69398 Overview

CVE-2025-69398 is a PHP Local File Inclusion (LFI) vulnerability affecting the ThemeREX Plank WordPress theme. The vulnerability stems from improper control of filename parameters used in PHP include/require statements, potentially allowing attackers to include local files from the server's filesystem. This vulnerability is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program).

Critical Impact

Successful exploitation of this LFI vulnerability could allow unauthenticated remote attackers to read sensitive files, access configuration data, or potentially achieve code execution through log poisoning or other advanced techniques.

Affected Products

• ThemeREX Plank WordPress Theme version 1.7 and earlier
• WordPress installations using the vulnerable Plank theme
• Web servers hosting affected WordPress sites

Discovery Timeline

• 2026-02-20 - CVE-2025-69398 published to NVD
• 2026-02-24 - Last updated in NVD database

Technical Details for CVE-2025-69398

Vulnerability Analysis

This vulnerability represents a classic PHP Local File Inclusion flaw in the ThemeREX Plank WordPress theme. The core issue lies in the theme's failure to properly validate and sanitize user-supplied input before using it in PHP include() or require() statements. When file path parameters are not adequately filtered, an attacker can manipulate these parameters to include arbitrary files from the local filesystem.

The network-accessible nature of this vulnerability means that remote attackers can potentially exploit it without requiring authentication. However, successful exploitation requires certain conditions to be met, such as the presence of exploitable files on the target system or specific server configurations.

Root Cause

The root cause of CVE-2025-69398 is insufficient input validation in the Plank theme's PHP code where user-controllable data is passed directly to file inclusion functions. The theme fails to implement proper allowlist-based validation or path canonicalization, allowing attackers to use directory traversal sequences (such as ../) to escape the intended directory scope and access files elsewhere on the filesystem.

Attack Vector

The attack vector for this vulnerability is network-based, allowing remote exploitation. An attacker would typically craft malicious HTTP requests containing manipulated file path parameters. These parameters could include directory traversal sequences to navigate the filesystem and include sensitive files such as:

• WordPress configuration files containing database credentials (wp-config.php)
• Server configuration files (/etc/passwd on Linux systems)
• Application logs that could be poisoned for code execution
• Other PHP files that could lead to further compromise

The vulnerability requires no user interaction and can be exploited without authentication, though the high attack complexity rating suggests that specific conditions must be present for successful exploitation.

Detection Methods for CVE-2025-69398

Indicators of Compromise

• Unusual HTTP requests containing directory traversal patterns such as ../, ..%2f, or similar encoded sequences targeting the Plank theme
• Web server logs showing access attempts to include files outside the theme directory
• Unexpected file access patterns in PHP logs or application monitoring
• Failed or successful attempts to access sensitive system files through web requests

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block directory traversal attempts in URL parameters and POST data
• Configure intrusion detection systems (IDS) to alert on patterns consistent with LFI exploitation attempts
• Enable detailed PHP error logging and monitor for include/require errors with unexpected file paths
• Deploy file integrity monitoring on critical WordPress and system configuration files

Monitoring Recommendations

• Monitor web server access logs for requests containing path traversal sequences targeting the Plank theme
• Set up alerts for unusual file read operations originating from the web server process
• Track PHP error logs for failed file inclusion attempts that may indicate exploitation attempts
• Implement network-level monitoring for exfiltration of sensitive data that could result from successful LFI attacks

How to Mitigate CVE-2025-69398

Immediate Actions Required

• Identify all WordPress installations using the ThemeREX Plank theme version 1.7 or earlier
• Consider temporarily disabling the Plank theme if it is not critical to site functionality
• Apply any available security patches from ThemeREX as they become available
• Implement WAF rules to block common LFI attack patterns as an interim protective measure
• Review server logs for any indication of exploitation attempts

Patch Information

At the time of publication, organizations should check with ThemeREX for updated versions of the Plank theme that address this vulnerability. The Patchstack WordPress Vulnerability Report provides additional details about this vulnerability and potential remediation steps. WordPress administrators should ensure they are running the latest patched version once it becomes available.

Workarounds

• Deploy a Web Application Firewall (WAF) with rules configured to block path traversal sequences and LFI attack patterns
• Implement PHP's open_basedir configuration directive to restrict which directories PHP can access for file operations
• Use server-level access controls to limit the web server process's ability to read sensitive files outside the WordPress installation
• Consider using virtual patching solutions that can protect against exploitation while awaiting an official fix
• Temporarily replace the vulnerable theme with an alternative if critical security requirements cannot otherwise be met

# Example PHP configuration to restrict file access scope
# Add to php.ini or .htaccess
php_value open_basedir /var/www/html/wordpress:/tmp

# Apache mod_security rule to block basic LFI patterns
SecRule ARGS "@contains ../" "id:1001,phase:1,deny,status:403,msg:'Potential LFI Attack'"