CVE-2025-54034: Newsletters Plugin File Inclusion Flaw

CVE-2025-54034 Overview

CVE-2025-54034 is a Local File Inclusion (LFI) vulnerability affecting the Tribulant Software Newsletters plugin (newsletters-lite) for WordPress. The vulnerability stems from improper control of filename for include/require statements in PHP, classified under CWE-98 (Improper Control of Filename for Include/Require Statement in PHP Program). This flaw allows attackers to include arbitrary local files on the server, potentially leading to sensitive information disclosure, configuration file exposure, or further exploitation through chained attacks.

Critical Impact

Attackers can exploit this vulnerability to read sensitive files from the WordPress server, potentially exposing database credentials, configuration files, and other critical data that could enable full system compromise.

Affected Products

• Tribulant Software Newsletters plugin (newsletters-lite) versions up to and including 4.10
• WordPress installations running the vulnerable Newsletters plugin
• All sites using newsletters-lite with default configurations

Discovery Timeline

• 2025-08-20 - CVE-2025-54034 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-54034

Vulnerability Analysis

This vulnerability is categorized as a PHP Local File Inclusion issue, which occurs when an application uses user-controlled input within file inclusion operations (such as include(), require(), include_once(), or require_once() statements) without proper validation or sanitization. The attack requires network access and some user interaction, though no prior authentication is needed to exploit it.

The Newsletters plugin fails to adequately sanitize user-supplied input before using it in file path operations. When exploited successfully, an attacker can force the application to include arbitrary files from the local file system, potentially exposing sensitive configuration data, source code, or system files.

Root Cause

The root cause lies in the improper validation of user-controlled input that is subsequently used in PHP file inclusion functions. The plugin does not implement sufficient path traversal protections or whitelist-based file inclusion controls, allowing attackers to manipulate file paths using directory traversal sequences (e.g., ../) or absolute paths to access files outside the intended directory scope.

Attack Vector

The vulnerability is exploitable over the network, requiring no prior privileges on the target system. However, some user interaction is required for successful exploitation. Attackers can craft malicious requests that manipulate file path parameters to include local files such as /etc/passwd, wp-config.php, or other sensitive WordPress configuration files.

A typical attack scenario involves:

1. Identifying a vulnerable parameter that accepts file path input
2. Injecting directory traversal sequences to escape the intended directory
3. Including sensitive local files to extract credentials or configuration data
4. Using exposed information for privilege escalation or further attacks

The vulnerability mechanism involves improper handling of user-supplied file paths within include statements. Attackers can manipulate input parameters to traverse directories and access sensitive files outside the plugin's intended scope. For detailed technical information, refer to the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2025-54034

Indicators of Compromise

• Unusual HTTP requests containing directory traversal patterns such as ../ or encoded variants (%2e%2e%2f)
• Access logs showing requests to sensitive file paths like /etc/passwd or wp-config.php
• Abnormal file access patterns from the web server process
• Failed or successful attempts to read files outside the plugin directory

Detection Strategies

• Deploy Web Application Firewall (WAF) rules to detect and block path traversal sequences in request parameters
• Monitor WordPress logs for suspicious requests targeting the Newsletters plugin endpoints
• Implement file integrity monitoring on critical WordPress configuration files
• Use security plugins that can detect LFI attack patterns in real-time

Monitoring Recommendations

• Enable detailed access logging on the web server to capture full request URIs
• Set up alerts for requests containing path traversal indicators (../, ..\\, encoded sequences)
• Monitor for unusual read access to sensitive system files from the web server user
• Review WordPress audit logs for plugin-related anomalies

How to Mitigate CVE-2025-54034

Immediate Actions Required

• Update the Newsletters plugin (newsletters-lite) to a patched version beyond 4.10 when available
• Temporarily disable the Newsletters plugin if no patch is available and functionality is not critical
• Implement WAF rules to block LFI attack patterns at the network perimeter
• Restrict file system permissions for the web server user to minimize exposure
• Review server logs for any signs of prior exploitation attempts

Patch Information

Organizations should monitor the official Tribulant Software channels and WordPress plugin repository for security updates addressing this vulnerability. The Patchstack WordPress Vulnerability Report provides additional details and patch status information.

Workarounds

• Implement mod_security or similar WAF rules to filter path traversal patterns
• Use PHP open_basedir directive to restrict file system access scope
• Apply principle of least privilege to web server file system permissions
• Consider using a virtual patching solution until an official fix is released
• Isolate the WordPress installation to limit potential impact of file disclosure

# Example Apache mod_rewrite rule to block path traversal attempts
# Add to .htaccess in WordPress root directory
RewriteEngine On
RewriteCond %{QUERY_STRING} (\.\./|\.\.\\) [NC,OR]
RewriteCond %{QUERY_STRING} (%2e%2e%2f|%2e%2e/) [NC,OR]
RewriteCond %{QUERY_STRING} (/etc/passwd|wp-config\.php) [NC]
RewriteRule .* - [F,L]