CVE-2025-23844: Custom Widget Classes CSRF Vulnerability

CVE-2025-23844 Overview

A Cross-Site Request Forgery (CSRF) vulnerability has been identified in the Custom Widget Classes WordPress plugin developed by Jamsheer K. This vulnerability allows attackers to craft malicious requests that, when executed by an authenticated administrator, can perform unauthorized actions on the WordPress site. According to security research, this CSRF vulnerability can be chained with Stored Cross-Site Scripting (XSS), significantly amplifying the potential impact.

Critical Impact

Attackers can exploit this CSRF vulnerability to perform unauthorized administrative actions and potentially inject persistent malicious scripts into the WordPress site when combined with the associated Stored XSS vulnerability.

Affected Products

• Custom Widget Classes WordPress Plugin version 1.1 and earlier

Discovery Timeline

• 2025-01-16 - CVE-2025-23844 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-23844

Vulnerability Analysis

This vulnerability exists in the Custom Widget Classes WordPress plugin, which is designed to add custom CSS classes to WordPress widgets. The plugin fails to implement proper CSRF protection mechanisms for state-changing requests, allowing attackers to forge requests that execute unauthorized actions under the context of an authenticated administrator.

The vulnerability is classified under CWE-352 (Cross-Site Request Forgery), indicating that the application does not properly verify whether a request was intentionally made by the user who submitted it. When an authenticated administrator visits a malicious page or clicks a crafted link, the attacker's request will be executed with the administrator's privileges.

According to the Patchstack WordPress Vulnerability Report, this CSRF vulnerability can be leveraged to achieve Stored XSS, creating a more severe attack chain where malicious JavaScript can be persistently injected into the site.

Root Cause

The root cause of this vulnerability is the absence of nonce verification in the plugin's form submission handlers. WordPress provides a nonce system (wp_nonce_field() and wp_verify_nonce()) specifically designed to prevent CSRF attacks, but the Custom Widget Classes plugin does not implement these security controls on sensitive operations. This allows attackers to craft requests that bypass the same-origin policy protections normally enforced by web browsers.

Attack Vector

The attack vector involves social engineering an authenticated WordPress administrator to visit a malicious webpage or click a specially crafted link. The attacker's page contains hidden form elements or JavaScript that automatically submits a forged request to the vulnerable WordPress plugin endpoint. Since the administrator's browser automatically includes authentication cookies with the request, the malicious action is executed with full administrative privileges.

The attack chain typically involves:

1. Attacker identifies a WordPress site using the vulnerable Custom Widget Classes plugin
2. Attacker crafts a malicious HTML page containing a forged form submission
3. Attacker tricks an authenticated administrator into visiting the malicious page
4. The forged request is submitted to the WordPress site using the administrator's session
5. The plugin processes the request without validating its origin, leading to Stored XSS

Detection Methods for CVE-2025-23844

Indicators of Compromise

• Unexpected modifications to widget CSS classes in WordPress admin panel
• Presence of JavaScript code or suspicious HTML in widget class fields
• Unusual form submissions to plugin endpoints in web server access logs
• Referrer headers showing requests originating from external or unknown domains

Detection Strategies

• Monitor WordPress activity logs for unexpected widget configuration changes
• Implement Content Security Policy (CSP) headers to detect and prevent inline script execution
• Review web application firewall (WAF) logs for suspicious POST requests to plugin endpoints
• Audit the plugin settings page for unauthorized modifications or injected content

Monitoring Recommendations

• Enable WordPress audit logging to track all administrative actions
• Configure alerts for widget-related configuration changes outside of normal business hours
• Monitor for outbound connections from the WordPress site that may indicate XSS payload execution
• Regularly review plugin settings for signs of tampering or malicious content injection

How to Mitigate CVE-2025-23844

Immediate Actions Required

• Deactivate and remove the Custom Widget Classes plugin (custom-widget-classes) immediately if not essential
• Review widget configurations for any suspicious or injected JavaScript code
• Clear browser cache and WordPress object cache after removing potentially malicious content
• Consider implementing a Web Application Firewall (WAF) with CSRF protection rules

Patch Information

At the time of publication, users should check the WordPress plugin repository or the Patchstack security advisory for updates on patched versions. The vulnerability affects Custom Widget Classes version 1.1 and all prior versions.

Workarounds

• Remove the Custom Widget Classes plugin entirely if not critical to site functionality
• Implement additional security plugins that provide CSRF protection at the WordPress level
• Restrict administrator access to trusted IP addresses only using server-level firewall rules
• Use browser extensions that block cross-origin requests when administering WordPress sites
• Consider alternative widget styling solutions that have been audited for security vulnerabilities

# WordPress CLI commands to check plugin status and remove if necessary
# Check if the vulnerable plugin is installed
wp plugin list --name=custom-widget-classes --status=active

# Deactivate the plugin if present
wp plugin deactivate custom-widget-classes

# Remove the plugin entirely
wp plugin delete custom-widget-classes