CVE-2025-23442: Shockingly Big IE6 Warning CSRF Flaw

CVE-2025-23442 Overview

CVE-2025-23442 is a Cross-Site Request Forgery (CSRF) vulnerability in the WordPress plugin "Shockingly Big IE6 Warning" (shockingly-big-ie6-warning) developed by mschertel. This vulnerability allows attackers to chain CSRF with Stored Cross-Site Scripting (XSS), enabling malicious actors to inject persistent scripts into the WordPress site through forged requests.

Critical Impact

This vulnerability allows unauthenticated attackers to leverage CSRF to inject malicious JavaScript that persists in the WordPress database, potentially compromising all visitors to the affected site and enabling session hijacking, credential theft, or malware distribution.

Affected Products

• Shockingly Big IE6 Warning WordPress Plugin version 1.6.3 and earlier
• All WordPress installations running vulnerable versions of this plugin
• Sites where administrators have the plugin settings page accessible

Discovery Timeline

• 2025-01-16 - CVE-2025-23442 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-23442

Vulnerability Analysis

This vulnerability represents a dangerous chained attack combining Cross-Site Request Forgery (CSRF) with Stored Cross-Site Scripting (XSS). The Shockingly Big IE6 Warning plugin fails to properly implement CSRF token validation on its administrative settings forms. When an authenticated administrator visits a maliciously crafted page while logged into their WordPress dashboard, an attacker can exploit this weakness to submit unauthorized requests that modify the plugin's configuration.

The lack of proper nonce verification allows attackers to inject arbitrary JavaScript code into the plugin's settings fields. Since these settings are stored in the WordPress database and later rendered to site visitors, the injected scripts become persistent (Stored XSS). This vulnerability affects the confidentiality, integrity, and availability of the affected WordPress installation.

Root Cause

The root cause of CVE-2025-23442 is the absence of proper CSRF protection mechanisms in the plugin's administrative settings handler. WordPress provides built-in nonce verification functions (wp_nonce_field() and wp_verify_nonce()) that developers should implement to validate that form submissions originate from legitimate sources. The Shockingly Big IE6 Warning plugin through version 1.6.3 fails to implement these security controls, leaving the settings forms vulnerable to cross-origin requests.

Additionally, the plugin does not properly sanitize or escape user input before storing it in the database or rendering it on the frontend, enabling the Stored XSS component of this vulnerability chain.

Attack Vector

The attack requires user interaction where an authenticated WordPress administrator must visit a malicious webpage while logged into their WordPress site. The attacker crafts an HTML page containing a hidden form that automatically submits to the vulnerable plugin's settings endpoint. The attack flow proceeds as follows:

1. The attacker identifies a WordPress site running the vulnerable plugin version
2. The attacker creates a malicious webpage with an auto-submitting form targeting the plugin's settings page
3. The attacker tricks an authenticated administrator into visiting the malicious page
4. The hidden form submits a request to modify plugin settings with malicious JavaScript payload
5. The WordPress site processes the request without CSRF validation
6. The malicious script is stored in the database and executes for all visitors viewing pages where the plugin renders content

Since no verified exploit code is available, readers should refer to the Patchstack Vulnerability Advisory for technical details on the exploitation mechanism.

Detection Methods for CVE-2025-23442

Indicators of Compromise

• Unexpected or unauthorized JavaScript code present in the Shockingly Big IE6 Warning plugin settings
• Suspicious <script> tags or event handler attributes stored in plugin configuration
• Server access logs showing unexpected POST requests to the plugin settings page from external referrers
• Browser console errors or unusual network requests originating from the WordPress frontend

Detection Strategies

• Review the wp_options table for any suspicious entries related to the Shockingly Big IE6 Warning plugin containing JavaScript or HTML event handlers
• Monitor WordPress administrative action logs for settings changes occurring during unusual times or from unexpected IP addresses
• Implement 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 entries

Monitoring Recommendations

• Enable comprehensive logging for all WordPress administrative actions, particularly plugin settings modifications
• Implement real-time alerting for changes to plugin configurations on production WordPress sites
• Deploy Web Application Firewalls (WAF) to detect and block CSRF attack patterns and XSS payloads
• Regularly audit plugin settings and database entries for unexpected code injection

How to Mitigate CVE-2025-23442

Immediate Actions Required

• Deactivate and remove the Shockingly Big IE6 Warning plugin if it is not essential for site functionality
• Review the plugin settings in the WordPress database and remove any suspicious JavaScript or HTML code
• Audit user accounts for any unauthorized changes that may indicate successful exploitation
• Consider implementing a Web Application Firewall (WAF) rule to block requests to the vulnerable plugin endpoint

Patch Information

As of the available CVE data, all versions of the Shockingly Big IE6 Warning plugin through version 1.6.3 are affected. Site administrators should check with the plugin developer for security patches or updated versions that address this vulnerability. Refer to the Patchstack Vulnerability Advisory for the latest patch status and remediation guidance.

Workarounds

• Remove or deactivate the Shockingly Big IE6 Warning plugin until a patched version is available
• Implement additional CSRF protection at the web server or WAF level for the plugin's settings endpoints
• Restrict access to the WordPress admin panel to trusted IP addresses only
• Use browser security extensions that warn administrators when navigating away from the WordPress dashboard

# WordPress CLI command to deactivate the vulnerable plugin
wp plugin deactivate shockingly-big-ie6-warning

# Verify plugin is deactivated
wp plugin status shockingly-big-ie6-warning

# Optional: Remove the plugin entirely
wp plugin delete shockingly-big-ie6-warning