CVE-2025-24555: Subscription DNA CSRF Vulnerability

CVE-2025-24555 Overview

CVE-2025-24555 is a Cross-Site Request Forgery (CSRF) vulnerability in the WordPress Subscription DNA plugin (subscriptiondna) that can be leveraged to execute Stored Cross-Site Scripting (XSS) attacks. This chained vulnerability allows attackers to bypass CSRF protections and inject persistent malicious scripts into the web application, potentially compromising administrative users and site visitors.

Critical Impact

Attackers can exploit this CSRF-to-Stored-XSS chain to inject malicious JavaScript that persists in the application, potentially stealing admin credentials, hijacking sessions, or redirecting users to malicious sites.

Affected Products

• Subscription DNA WordPress Plugin versions through 2.1
• WordPress installations running vulnerable versions of the subscriptiondna plugin

Discovery Timeline

• 2025-01-24 - CVE-2025-24555 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-24555

Vulnerability Analysis

This vulnerability combines two distinct attack vectors into a potent exploitation chain. The primary weakness is a Cross-Site Request Forgery (CSRF) vulnerability classified under CWE-352, which occurs when the plugin fails to properly validate the origin of HTTP requests. When combined with insufficient input sanitization, attackers can leverage this CSRF weakness to inject persistent malicious scripts that execute in the browsers of subsequent visitors.

The attack requires user interaction—specifically, a victim must be tricked into visiting a malicious page or clicking a crafted link while authenticated to the WordPress site. The scope is changed (indicated in the CVSS vector), meaning the vulnerability can impact resources beyond the vulnerable component itself, affecting the confidentiality, integrity, and availability of the broader web application.

Root Cause

The root cause of this vulnerability is the absence of proper CSRF token validation in the Subscription DNA plugin's form handling mechanisms. Without anti-CSRF tokens (nonces in WordPress terminology), the plugin cannot verify that form submissions originate from legitimate user actions within the application. This allows attackers to craft malicious requests that are automatically executed by authenticated users' browsers. Additionally, insufficient output encoding allows injected content to be stored and later rendered as executable scripts.

Attack Vector

The attack is network-based and requires no prior authentication from the attacker. The exploitation flow typically involves:

1. An attacker identifies a form or action in the Subscription DNA plugin that lacks CSRF protection
2. The attacker crafts a malicious HTML page containing a hidden form that submits XSS payload to the vulnerable endpoint
3. When an authenticated WordPress administrator visits the attacker's page, their browser automatically submits the malicious request
4. The XSS payload is stored in the database and executes whenever users view the affected page

The vulnerability requires user interaction (social engineering to visit the malicious page), but once triggered, the stored XSS persists and can affect multiple victims without further attacker involvement.

Detection Methods for CVE-2025-24555

Indicators of Compromise

• Unexpected JavaScript code or <script> tags appearing in plugin-managed content or settings
• Database entries containing encoded or obfuscated script payloads in Subscription DNA plugin tables
• Browser console errors or suspicious network requests originating from plugin-rendered pages
• Admin user accounts reporting unexpected session behavior or credential prompts

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect CSRF attack patterns and XSS payload signatures
• Monitor server access logs for suspicious POST requests to Subscription DNA plugin endpoints from external referrers
• Deploy Content Security Policy (CSP) headers to detect and block unauthorized inline script execution
• Use WordPress security plugins to scan for stored XSS payloads in database content

Monitoring Recommendations

• Enable detailed logging for all plugin-related form submissions and administrative actions
• Configure alerts for changes to plugin settings or content modifications performed via unusual request patterns
• Regularly audit database content for suspicious script tags or encoded payloads
• Monitor for JavaScript errors or CSP violation reports that may indicate XSS execution attempts

How to Mitigate CVE-2025-24555

Immediate Actions Required

• Temporarily disable the Subscription DNA plugin if it is not critical to site operations
• Review and remove any suspicious content that may have been injected via this vulnerability
• Implement additional WAF rules to block requests missing proper CSRF tokens
• Audit administrator accounts for unauthorized access and reset credentials if necessary

Patch Information

As of the last NVD update, the vulnerability affects Subscription DNA plugin versions through 2.1. Administrators should check for updated versions that address this CSRF vulnerability. Consult the Patchstack WordPress Vulnerability Report for the latest patch status and remediation guidance from the security researchers who identified this issue.

Workarounds

• Implement server-side request validation to check the Referer header for all state-changing requests
• Add additional authentication layers such as CAPTCHA for sensitive form submissions
• Use security plugins like Wordfence or Sucuri that provide virtual patching capabilities
• Configure strict Content Security Policy headers to prevent inline script execution

# Example WordPress .htaccess rules to add Referer checking
# Add to WordPress root .htaccess file
<IfModule mod_rewrite.c>
    RewriteEngine On
    # Block POST requests without proper Referer header
    RewriteCond %{REQUEST_METHOD} POST
    RewriteCond %{HTTP_REFERER} !^https?://(www\.)?yourdomain\.com [NC]
    RewriteCond %{REQUEST_URI} subscriptiondna [NC]
    RewriteRule .* - [F,L]
</IfModule>