CVE-2025-39418: RSS Manager CSRF/XSS Vulnerability

CVE-2025-39418 Overview

CVE-2025-39418 is a Cross-Site Request Forgery (CSRF) vulnerability in the RSS Manager WordPress plugin (developed by ajayver) that enables attackers to execute Stored Cross-Site Scripting (XSS) attacks. This chained vulnerability allows remote attackers to trick authenticated administrators into unknowingly submitting malicious requests, which can then inject persistent JavaScript payloads into the WordPress site.

Critical Impact

Attackers can leverage CSRF to inject stored XSS payloads that execute in the browsers of all site visitors, potentially leading to session hijacking, credential theft, and complete site compromise.

Affected Products

• RSS Manager WordPress Plugin version 0.06 and earlier
• All WordPress installations running vulnerable versions of the rss-manager plugin
• Sites where administrators access untrusted links while authenticated to the WordPress dashboard

Discovery Timeline

• 2025-04-17 - CVE-2025-39418 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-39418

Vulnerability Analysis

This vulnerability represents a dangerous attack chain combining CSRF with Stored XSS. The RSS Manager plugin fails to implement proper anti-CSRF protections (such as nonce verification) on administrative actions that handle user-supplied input. Furthermore, the plugin does not adequately sanitize or escape input data before storing it in the database and rendering it on pages.

The network-based attack vector requires user interaction—specifically, an authenticated administrator must be tricked into clicking a malicious link or visiting an attacker-controlled page. Once the CSRF is successful, the injected XSS payload becomes persistently stored in the WordPress database, executing each time the affected content is rendered.

The impact spans confidentiality, integrity, and availability concerns. The changed scope indicates that the vulnerability can affect resources beyond the vulnerable component itself, meaning malicious scripts can target other users and potentially other applications served from the same origin.

Root Cause

The root cause is twofold:

1. Missing CSRF Token Validation (CWE-352): The plugin does not verify WordPress nonces or implement other anti-CSRF mechanisms on sensitive administrative forms and actions.

2. Insufficient Input Sanitization: User-supplied data is stored and subsequently rendered without proper output encoding, allowing JavaScript injection.

This combination allows attackers to bypass the same-origin policy protection that would normally prevent cross-site form submissions from having meaningful effects.

Attack Vector

The attack proceeds in the following stages:

1. Reconnaissance: The attacker identifies a WordPress site running the vulnerable RSS Manager plugin version 0.06 or earlier.

2. Payload Crafting: The attacker creates a malicious HTML page containing a hidden form that targets the RSS Manager plugin's administrative endpoints with XSS payload data.

3. Social Engineering: The attacker lures an authenticated WordPress administrator to visit the malicious page—via phishing email, compromised website, or malicious advertisement.

4. CSRF Execution: The victim's browser automatically submits the form using the administrator's session cookies, bypassing authentication.

5. XSS Storage: The malicious JavaScript payload is stored in the WordPress database through the vulnerable plugin functionality.

6. Payload Execution: The stored XSS executes whenever the affected page is loaded, impacting all visitors including other administrators, potentially exfiltrating session tokens, injecting further malware, or performing actions on behalf of authenticated users.

Detection Methods for CVE-2025-39418

Indicators of Compromise

• Unexpected JavaScript code or <script> tags appearing in RSS Manager plugin settings or displayed content
• Unusual outbound connections from visitor browsers to external domains
• Administrator accounts reporting actions they did not perform
• Web application firewall (WAF) logs showing blocked XSS patterns targeting RSS Manager endpoints

Detection Strategies

• Review WordPress database tables associated with the RSS Manager plugin for suspicious HTML or JavaScript content
• Monitor HTTP request logs for POST requests to RSS Manager endpoints that lack valid WordPress nonces
• Implement Content Security Policy (CSP) headers and monitor for CSP violation reports indicating XSS attempts
• Use WordPress security plugins to scan for known vulnerable plugin versions

Monitoring Recommendations

• Enable and review WordPress audit logs for changes to plugin settings
• Configure web server access logs to capture full POST request bodies for forensic analysis
• Set up alerts for new or modified JavaScript content in RSS-related database entries
• Deploy endpoint detection and response (EDR) solutions to identify malicious browser behavior

How to Mitigate CVE-2025-39418

Immediate Actions Required

• Immediately disable or uninstall the RSS Manager (rss-manager) plugin until a patched version is available
• Audit WordPress database for any previously injected malicious content in plugin-related tables
• Review administrator access logs for suspicious activity patterns
• Consider implementing a Web Application Firewall (WAF) rule to block requests to vulnerable endpoints

Patch Information

As of the last update, no patched version has been confirmed. Site administrators should monitor the Patchstack Security Advisory for updates on vendor response and patch availability. If the plugin is no longer maintained, consider migrating to an alternative RSS management solution.

Workarounds

• Remove the RSS Manager plugin entirely and use a maintained alternative RSS plugin with proper security controls
• If the plugin must remain active, restrict administrative access to trusted IP addresses only
• Implement HTTP-only and Secure flags on all WordPress session cookies to limit XSS impact
• Deploy a WAF rule to enforce nonce verification on plugin administrative endpoints

# WordPress CLI command to deactivate the vulnerable plugin
wp plugin deactivate rss-manager

# Search for potentially injected XSS payloads in WordPress database
wp db query "SELECT * FROM wp_options WHERE option_name LIKE '%rss%' AND option_value LIKE '%<script%'"