CVE-2025-28998: SERPed.net File Inclusion Vulnerability

CVE-2025-28998 Overview

CVE-2025-28998 is a PHP Local File Inclusion (LFI) vulnerability affecting the SERPed.net WordPress plugin developed by serpednet. 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 security flaw allows attackers to include local files from the server, potentially leading to sensitive information disclosure, configuration file exposure, or further exploitation when combined with other attack vectors.

Critical Impact

Attackers can exploit this Local File Inclusion vulnerability to read sensitive files from the server, potentially exposing configuration data, credentials, or system information that could facilitate further attacks.

Affected Products

• SERPed.net WordPress Plugin versions through 4.6
• WordPress installations running the vulnerable serped-net plugin

Discovery Timeline

• 2025-06-27 - CVE-2025-28998 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2025-28998

Vulnerability Analysis

This vulnerability is classified as a PHP Local File Inclusion (LFI) issue resulting from improper control of filename parameters used in PHP include or require statements. The SERPed.net WordPress plugin fails to properly sanitize user-supplied input before using it to construct file paths for PHP file inclusion operations.

When exploited, attackers can manipulate the file path parameter to include arbitrary local files from the web server. This can result in the disclosure of sensitive system files such as /etc/passwd, WordPress configuration files like wp-config.php, or other application files containing credentials and configuration data.

Root Cause

The root cause of CVE-2025-28998 is inadequate input validation and sanitization of user-controlled parameters that are subsequently used in PHP's include(), require(), include_once(), or require_once() functions. The plugin does not implement proper path traversal filtering or whitelist-based validation to restrict which files can be included.

Attack Vector

The attack leverages path traversal sequences (such as ../) combined with the vulnerable file inclusion functionality. An attacker can craft malicious requests containing directory traversal characters to escape the intended directory and access files elsewhere on the filesystem. The attack is typically executed through HTTP requests to the WordPress site with specially crafted parameters targeting the vulnerable plugin functionality.

Successful exploitation requires the attacker to identify the vulnerable parameter and craft a request that navigates to the target file. Common targets include WordPress configuration files, system password files, and log files that may contain sensitive information.

Detection Methods for CVE-2025-28998

Indicators of Compromise

• Unusual HTTP requests containing path traversal sequences (../, ..%2f, ....//) targeting plugin endpoints
• Web server logs showing attempts to access system files like /etc/passwd or wp-config.php
• Requests to the SERPed.net plugin endpoints with file path parameters containing encoded traversal characters
• Anomalous file access patterns on the web server outside the expected plugin directories

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block path traversal patterns in HTTP requests
• Monitor WordPress audit logs for suspicious plugin activity and file access attempts
• Deploy intrusion detection signatures targeting LFI attack patterns specific to PHP applications
• Review web server access logs for requests containing ../ sequences or encoded variants targeting the serped-net plugin

Monitoring Recommendations

• Enable verbose logging on the WordPress installation and web server to capture detailed request information
• Configure alerts for file access attempts outside normal web directories
• Implement file integrity monitoring on critical configuration files like wp-config.php
• Set up real-time monitoring for HTTP requests containing known LFI attack patterns

How to Mitigate CVE-2025-28998

Immediate Actions Required

• Deactivate and remove the SERPed.net plugin if not essential to site operations
• Implement WAF rules to block path traversal attacks targeting the vulnerable plugin
• Review web server logs for signs of exploitation attempts
• Audit file permissions to ensure sensitive files are not world-readable
• Consider implementing additional server-side restrictions on file inclusion paths

Patch Information

At the time of publication, users should check the Patchstack vulnerability database for the latest patch information and remediation guidance. Plugin updates should be applied through the WordPress admin dashboard once a patched version becomes available. Users are advised to update to a version higher than 4.6 when released.

Workarounds

• Disable the SERPed.net plugin until a security patch is available
• Implement server-level restrictions using open_basedir PHP directive to limit file inclusion paths
• Deploy a Web Application Firewall with rules specifically targeting LFI/path traversal attacks
• Apply principle of least privilege to file system permissions, ensuring the web server user cannot read sensitive system files

# PHP configuration hardening example
# Add to php.ini or .htaccess to restrict file inclusion paths
# Limits PHP file operations to specific directories

php_value open_basedir /var/www/html/:/tmp/