CVE-2025-54017: Paid Member Subscriptions LFI Vulnerability

CVE-2025-54017 Overview

CVE-2025-54017 is a Local File Inclusion (LFI) vulnerability affecting the Cozmoslabs Paid Member Subscriptions WordPress plugin. This vulnerability stems from improper control of filename parameters used in PHP include/require statements, allowing attackers to include arbitrary local files on the server. When successfully exploited, this vulnerability can lead to sensitive information disclosure, including configuration files, credentials, and potentially remote code execution through log poisoning or other advanced techniques.

Critical Impact

Attackers can exploit this LFI vulnerability to read sensitive server files, potentially exposing database credentials, WordPress configuration details, and other confidential data that could be leveraged for further attacks against the affected system.

Affected Products

• Cozmoslabs Paid Member Subscriptions plugin version 2.15.4 and earlier
• WordPress installations running vulnerable versions of the paid-member-subscriptions plugin

Discovery Timeline

• 2025-08-20 - CVE-2025-54017 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-54017

Vulnerability Analysis

This vulnerability is classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program). The Paid Member Subscriptions plugin fails to properly sanitize user-controlled input before using it in PHP include or require statements. This allows an attacker to manipulate the file path and include arbitrary files from the local file system.

The attack requires network access and some level of user interaction, making it slightly more complex to exploit than straightforward injection vulnerabilities. However, successful exploitation can result in complete compromise of confidentiality, integrity, and availability of the affected system.

Root Cause

The root cause of this vulnerability lies in insufficient input validation and sanitization of file path parameters within the Paid Member Subscriptions plugin. When user-supplied input is directly concatenated into file include paths without proper validation, attackers can use directory traversal sequences (such as ../) to navigate outside the intended directory and include sensitive system files.

PHP's include and require functions will execute any PHP code found within the included file, which significantly amplifies the risk if attackers can influence the contents of any includable file (such as through log poisoning or file upload vulnerabilities).

Attack Vector

The vulnerability is exploitable over the network, though it requires user interaction to trigger. An attacker would typically craft a malicious request containing directory traversal sequences targeting the vulnerable parameter in the Paid Member Subscriptions plugin. Common exploitation targets include:

• /etc/passwd - To enumerate system users
• wp-config.php - To extract database credentials and authentication keys
• Log files - For potential log poisoning and subsequent code execution
• Session files - To hijack active user sessions

The exploitation pattern typically involves manipulating URL parameters or POST data to include sequences like ../../wp-config.php or similar traversal patterns to access files outside the intended scope.

Detection Methods for CVE-2025-54017

Indicators of Compromise

• Unusual HTTP requests containing directory traversal patterns (../, ..%2f, %2e%2e/) in parameters related to the Paid Member Subscriptions plugin
• Unexpected file access attempts in web server logs targeting sensitive files like wp-config.php, /etc/passwd, or log files
• Anomalous error messages in PHP logs indicating failed file inclusion attempts
• Evidence of sensitive file contents being transmitted in HTTP responses

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block directory traversal patterns in HTTP requests
• Enable comprehensive logging for the WordPress installation and monitor for suspicious file inclusion attempts
• Implement file integrity monitoring on critical WordPress and system files
• Configure intrusion detection systems to alert on known LFI exploitation patterns
• Monitor for unusual PHP error messages that may indicate exploitation attempts

Monitoring Recommendations

• Review web server access logs regularly for requests containing traversal sequences targeting the paid-member-subscriptions plugin endpoints
• Set up alerts for access attempts to sensitive configuration files from web processes
• Monitor outbound network traffic for potential data exfiltration following successful exploitation
• Implement real-time log analysis to detect rapid exploitation attempts

How to Mitigate CVE-2025-54017

Immediate Actions Required

• Update the Paid Member Subscriptions plugin to a version newer than 2.15.4 that addresses this vulnerability
• Review web server logs for evidence of exploitation attempts
• Implement WAF rules to block directory traversal patterns as a temporary protective measure
• Consider temporarily disabling the plugin if an update is not immediately available and the functionality is not critical

Patch Information

Users should update the Paid Member Subscriptions plugin to the latest available version through the WordPress admin dashboard or by downloading directly from the official WordPress plugin repository. For detailed vulnerability information and patch status, refer to the Patchstack WordPress Vulnerability Report.

Workarounds

• Implement server-level restrictions using open_basedir PHP directive to limit file access to the WordPress directory
• Deploy a Web Application Firewall with rules specifically designed to block LFI and directory traversal attacks
• Restrict file system permissions to ensure the web server process cannot read sensitive system files
• Consider using WordPress security plugins that provide virtual patching capabilities for known vulnerabilities

# Apache .htaccess rule to block common directory traversal patterns
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./) [NC,OR]
RewriteCond %{QUERY_STRING} (\.\.%2f) [NC,OR]
RewriteCond %{QUERY_STRING} (%2e%2e/) [NC]
RewriteRule .* - [F,L]