CVE-2019-25295: WP Cost Estimation Path Traversal Flaw

CVE-2019-25295 Overview

CVE-2019-25295 is a Directory Traversal vulnerability affecting the WP Cost Estimation plugin for WordPress. The vulnerability exists in versions prior to 9.660 and resides in the uploadFormFiles function. This flaw allows unauthenticated attackers to perform upload directory traversal, enabling them to overwrite arbitrary files on the affected WordPress site, provided those files have a whitelisted file extension.

Critical Impact

Attackers can exploit this vulnerability to overwrite critical files on WordPress installations, potentially leading to site defacement, persistent backdoor installation, or denial of service by overwriting essential configuration files.

Affected Products

• WP Cost Estimation & Payment Forms Builder plugin for WordPress (versions before 9.660)
• WordPress sites running vulnerable versions of the plugin
• Any WordPress installation with the affected plugin installed regardless of WordPress core version

Discovery Timeline

• 2019-02 - Vulnerability patched in WP Cost Estimation plugin version 9.660
• 2026-01-08 - CVE CVE-2019-25295 published to NVD
• 2026-01-08 - Last updated in NVD database

Technical Details for CVE-2019-25295

Vulnerability Analysis

This vulnerability falls under the CWE-22 (Improper Limitation of a Pathname to a Restricted Directory) category. The uploadFormFiles function in the WP Cost Estimation plugin fails to properly sanitize user-supplied path input during file upload operations. This lack of validation allows attackers to traverse directories using path manipulation techniques, escaping the intended upload directory and writing files to arbitrary locations on the web server's file system.

The attack can be executed remotely over the network without requiring any prior authentication or user interaction. While the vulnerability does not directly expose confidential data, successful exploitation can compromise the integrity and availability of the WordPress installation by allowing unauthorized file modifications.

Root Cause

The root cause of this vulnerability is insufficient input validation in the uploadFormFiles function. The function accepts user-controlled path data without adequately sanitizing directory traversal sequences such as ../ patterns. This allows attackers to construct malicious file paths that escape the designated upload directory, though exploitation is limited to overwriting files with extensions that match the plugin's whitelist configuration.

Attack Vector

The attack vector is network-based and requires no authentication, making it accessible to any remote attacker. The exploitation process involves:

1. An attacker identifies a WordPress site running a vulnerable version of the WP Cost Estimation plugin
2. The attacker crafts a malicious file upload request to the uploadFormFiles function
3. The request includes path traversal sequences (e.g., ../../../) in the filename or path parameter
4. The server processes the upload without properly sanitizing the path
5. The uploaded file overwrites an existing file at the traversed location, provided the file extension is whitelisted

The vulnerability mechanism involves improper path sanitization in the file upload handler. When processing uploaded files, the uploadFormFiles function constructs the destination path using user-supplied input without adequately filtering directory traversal sequences. An attacker can include sequences like ../ in their request to navigate outside the intended upload directory. For detailed technical analysis, refer to the Wordfence Vulnerability Blog Post.

Detection Methods for CVE-2019-25295

Indicators of Compromise

• Unexpected file modifications in WordPress core directories or wp-config.php
• Presence of newly created files with whitelisted extensions in unusual locations
• Web server access logs showing requests to WP Cost Estimation plugin endpoints with path traversal patterns (../)
• Modified timestamps on critical WordPress files that shouldn't have changed

Detection Strategies

• Monitor web server access logs for HTTP requests containing encoded or plain-text path traversal sequences targeting the plugin's upload endpoints
• Implement file integrity monitoring on critical WordPress directories to detect unauthorized modifications
• Use a Web Application Firewall (WAF) to detect and block requests containing directory traversal patterns
• Review WordPress plugin audit logs for anomalous upload activity

Monitoring Recommendations

• Configure real-time alerting for file modifications in wp-includes, wp-admin, and theme directories
• Implement centralized logging for all WordPress plugin activity with correlation rules for path traversal patterns
• Deploy endpoint detection and response (EDR) solutions to monitor file system changes on web servers
• Regularly audit installed plugin versions against known vulnerability databases

How to Mitigate CVE-2019-25295

Immediate Actions Required

• Update WP Cost Estimation plugin to version 9.660 or later immediately
• Conduct a file integrity scan to identify any files that may have been overwritten
• Review web server logs for evidence of exploitation attempts
• Consider temporarily disabling the plugin if immediate update is not possible

Patch Information

The vulnerability has been addressed in WP Cost Estimation plugin version 9.660. Site administrators should update to this version or later through the WordPress plugin management interface or by downloading the patched version from Codecanyon. After updating, verify the plugin version is correctly reflected in the WordPress admin panel.

For additional vulnerability details, refer to the Wordfence Threat Intel Report.

Workarounds

• If patching is not immediately possible, disable the WP Cost Estimation plugin until the update can be applied
• Implement WAF rules to block requests containing path traversal patterns targeting the plugin's endpoints
• Restrict file upload functionality through server-level configuration if the feature is not required
• Apply restrictive file permissions to prevent the web server process from writing to sensitive directories

# Configuration example - Restrict file permissions on critical directories
# Prevent write access to wp-config.php
chmod 440 /var/www/html/wp-config.php

# Set restrictive permissions on wp-includes directory
find /var/www/html/wp-includes -type f -exec chmod 644 {} \;
find /var/www/html/wp-includes -type d -exec chmod 755 {} \;

# Enable file integrity monitoring (example using AIDE)
aide --init
cp /var/lib/aide/aide.db.new /var/lib/aide/aide.db