CVE-2025-49425: Konami Easter Egg CSRF Vulnerability

CVE-2025-49425 Overview

CVE-2025-49425 is a Cross-Site Request Forgery (CSRF) vulnerability in the WordPress Konami Easter Egg plugin by Adrian Hanft. This vulnerability allows attackers to perform unauthorized actions on behalf of authenticated users, ultimately enabling Stored Cross-Site Scripting (XSS) attacks. The vulnerability affects all versions of the konami-easter-egg plugin through version 0.4.

Critical Impact

Attackers can exploit this CSRF vulnerability to inject malicious scripts that persist in the WordPress database, potentially compromising administrator sessions and enabling further attacks against site visitors.

Affected Products

• WordPress Konami Easter Egg plugin (konami-easter-egg) versions through <= v0.4
• WordPress installations using the affected plugin versions

Discovery Timeline

• 2025-06-06 - CVE-2025-49425 published to NVD
• 2026-04-01 - Last updated in NVD database

Technical Details for CVE-2025-49425

Vulnerability Analysis

This vulnerability combines two distinct attack vectors: Cross-Site Request Forgery (CSRF) and Stored Cross-Site Scripting (XSS). The Konami Easter Egg plugin, which adds a playful Easter egg feature triggered by the famous Konami Code input sequence, fails to implement proper CSRF protection on its administrative endpoints.

The absence of nonce verification allows attackers to craft malicious requests that, when executed by an authenticated administrator, can modify plugin settings without proper authorization. More critically, the input fields in the plugin's configuration do not properly sanitize user-supplied data before storing it in the WordPress database, enabling persistent XSS payloads.

When the malicious script is stored, it executes every time the affected page or admin interface is loaded, potentially compromising any user who views the page containing the Easter egg functionality.

Root Cause

The root cause of this vulnerability is twofold:

1. Missing CSRF Token Validation (CWE-352): The plugin's form submission handlers do not verify WordPress nonces, which are designed to prevent cross-site request forgery attacks. Without nonce verification, the plugin cannot distinguish between legitimate administrative actions and forged requests from malicious sites.

2. Insufficient Input Sanitization: User-supplied input is stored in the database without proper escaping or sanitization, allowing JavaScript payloads to be persisted and later rendered in the browser context.

Attack Vector

The attack scenario typically unfolds as follows:

1. An attacker creates a malicious webpage containing a hidden form that targets the vulnerable plugin's settings endpoint
2. The form includes XSS payloads in the configuration fields
3. When an authenticated WordPress administrator visits the attacker's page, the form automatically submits via JavaScript
4. The plugin processes the request without CSRF validation and stores the malicious payload
5. The stored XSS payload executes whenever users interact with the Easter egg functionality, potentially stealing session cookies or performing actions as the victim

For detailed technical information about this vulnerability, refer to the Patchstack WordPress CSRF Vulnerability advisory.

Detection Methods for CVE-2025-49425

Indicators of Compromise

• Unexpected changes to Konami Easter Egg plugin settings without administrator action
• JavaScript code present in plugin configuration fields or database entries related to the plugin
• Suspicious outbound requests originating from WordPress admin or frontend pages
• Browser console errors indicating script execution from unexpected sources

Detection Strategies

• Monitor WordPress admin activity logs for configuration changes to the konami-easter-egg plugin options
• Implement Content Security Policy (CSP) headers to detect and block unauthorized script execution
• Review database entries in the WordPress options table for unexpected script tags or encoded payloads
• Use WordPress security plugins that scan for known malicious patterns in stored content

Monitoring Recommendations

• Enable WordPress audit logging to track all administrative actions and plugin configuration changes
• Configure Web Application Firewall (WAF) rules to alert on CSRF attack patterns targeting WordPress plugin endpoints
• Implement real-time monitoring for DOM modifications that may indicate XSS payload execution
• Set up alerts for unusual JavaScript execution patterns on WordPress-powered sites

How to Mitigate CVE-2025-49425

Immediate Actions Required

• Deactivate and remove the Konami Easter Egg plugin (konami-easter-egg) version 0.4 and earlier from all WordPress installations
• Review WordPress database for any suspicious content stored in plugin-related options
• Clear browser caches and cookies for all administrators who may have been exposed
• Audit administrator session activity for any unauthorized actions that may have occurred

Patch Information

At the time of publication, no patched version has been officially confirmed. Organizations should monitor the Patchstack advisory for updates regarding a security fix. Until a patch is available, the recommended course of action is to completely remove the plugin.

Workarounds

• Remove the konami-easter-egg plugin entirely until a patched version is available
• Implement a Web Application Firewall (WAF) with rules to block CSRF attacks targeting WordPress plugin endpoints
• Apply Content Security Policy headers to restrict inline script execution and mitigate XSS impact
• Restrict WordPress admin access to trusted IP addresses to limit the attack surface for CSRF exploitation
• Regularly review and audit installed WordPress plugins for security vulnerabilities

# Deactivate and remove the vulnerable plugin via WP-CLI
wp plugin deactivate konami-easter-egg --path=/var/www/html/wordpress
wp plugin delete konami-easter-egg --path=/var/www/html/wordpress

# Search for potentially malicious content in the database
wp db search "<script" --path=/var/www/html/wordpress
wp db search "javascript:" --path=/var/www/html/wordpress