CVE-2019-25314: Duplicate Post WordPress Plugin XSS Flaw

CVE-2019-25314 Overview

CVE-2019-25314 is a persistent cross-site scripting (XSS) vulnerability affecting the Duplicate-Post WordPress Plugin version 3.2.3. The vulnerability exists in multiple plugin settings parameters, allowing attackers with authenticated access to inject malicious JavaScript code that persists in the WordPress admin interface and executes when other administrators view the affected settings pages.

Critical Impact

Authenticated attackers can inject persistent malicious scripts into the plugin's settings fields, potentially compromising administrator sessions, stealing credentials, or performing unauthorized actions within the WordPress admin panel.

Affected Products

• Duplicate-Post WordPress Plugin version 3.2.3
• WordPress installations using the vulnerable plugin version

Discovery Timeline

• 2026-02-11 - CVE-2019-25314 published to NVD
• 2026-02-11 - Last updated in NVD database

Technical Details for CVE-2019-25314

Vulnerability Analysis

This persistent cross-site scripting vulnerability (CWE-79) exists in the Duplicate-Post WordPress plugin's settings page. The vulnerability stems from improper sanitization of user-supplied input in several configuration fields. When an authenticated user with sufficient privileges modifies the plugin settings, the input values for title prefix, title suffix, menu order, and blacklist fields are stored without adequate output encoding. These malicious payloads are then rendered in the admin interface without proper escaping, causing the injected JavaScript to execute in the context of any administrator who views the settings page.

The attack requires authenticated access to the WordPress administration panel with permissions to modify plugin settings. Once the malicious payload is stored, it persists in the database and executes each time the settings page is loaded, making this a stored XSS attack with potential for session hijacking, privilege escalation, or further compromise of the WordPress installation.

Root Cause

The root cause of this vulnerability is insufficient input validation and output encoding in the Duplicate-Post plugin's settings handling functions. The plugin fails to properly sanitize user input before storing it in the database and does not apply adequate HTML entity encoding when rendering these values back to the admin interface. Specifically, the title prefix, title suffix, menu order, and blacklist configuration parameters accept and store arbitrary HTML and JavaScript content without filtering.

Attack Vector

The attack is network-based and requires authenticated access to the WordPress admin panel. An attacker with plugin configuration privileges can navigate to the Duplicate-Post settings page and inject malicious JavaScript payloads into the vulnerable fields. The injected script is stored in the WordPress database and executed whenever an administrator loads the settings page.

The exploitation process involves crafting JavaScript payloads designed to steal session cookies, redirect administrators to phishing pages, or perform administrative actions on behalf of the victim. Since WordPress plugins often have broad access to site functionality, successful exploitation can lead to complete site compromise. For detailed technical information about the exploitation methodology, refer to the Exploit-DB #47424 entry and the VulnCheck Advisory.

Detection Methods for CVE-2019-25314

Indicators of Compromise

• Unexpected JavaScript code or HTML tags present in Duplicate-Post plugin settings fields (title prefix, suffix, menu order, blacklist)
• Suspicious <script> tags, event handlers (onerror, onload, onclick), or encoded JavaScript in database records for the plugin options
• Unusual admin session activity or unauthorized administrative actions following visits to the plugin settings page

Detection Strategies

• Review WordPress database entries for the Duplicate-Post plugin options containing script tags or encoded JavaScript payloads
• Monitor web application firewall logs for XSS patterns in POST requests targeting the plugin settings endpoint
• Implement Content Security Policy (CSP) headers to detect and block inline script execution attempts

Monitoring Recommendations

• Enable WordPress audit logging to track changes to plugin settings and identify unauthorized modifications
• Configure web application firewalls to alert on common XSS payload patterns in form submissions
• Periodically scan plugin configuration tables for anomalous content using automated security tools

How to Mitigate CVE-2019-25314

Immediate Actions Required

• Update the Duplicate-Post plugin to the latest version that addresses this vulnerability
• Review current plugin settings for any suspicious content and remove malicious payloads
• Audit WordPress user accounts and revoke unnecessary administrative privileges
• Implement Content Security Policy headers to mitigate the impact of any stored XSS payloads

Patch Information

The vulnerability affects Duplicate-Post WordPress Plugin version 3.2.3. Administrators should update to the latest available version from the WordPress Plugin Directory or the official plugin site. After updating, review and re-save the plugin settings to ensure any existing malicious payloads are properly sanitized by the patched code.

Workarounds

• Restrict access to WordPress plugin settings pages to only trusted administrators
• Implement a Web Application Firewall (WAF) with XSS filtering rules to block malicious payloads before they reach the application
• Deploy Content Security Policy headers with strict inline script restrictions to prevent execution of injected JavaScript

# Add Content Security Policy header in Apache .htaccess
Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none';"

# Add CSP header in Nginx configuration
add_header Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none';" always;