CVE-2025-24562: KBucket CSRF & Stored XSS Vulnerability

CVE-2025-24562 Overview

CVE-2025-24562 is a Cross-Site Request Forgery (CSRF) vulnerability in the Optimal Access KBucket WordPress plugin that enables attackers to perform Stored Cross-Site Scripting (XSS) attacks. This chained vulnerability allows malicious actors to trick authenticated administrators into performing unintended actions, ultimately resulting in the injection of persistent malicious scripts into the WordPress site.

Critical Impact

This CSRF-to-Stored-XSS vulnerability chain allows attackers to inject persistent malicious JavaScript that executes in the context of any user viewing affected pages, potentially leading to session hijacking, credential theft, or complete site compromise.

Affected Products

• Optimal Access KBucket WordPress Plugin versions through 4.1.6
• WordPress installations running vulnerable KBucket plugin versions

Discovery Timeline

• 2025-01-24 - CVE CVE-2025-24562 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-24562

Vulnerability Analysis

This vulnerability represents a dangerous combination of two web application security flaws working in concert. The KBucket WordPress plugin fails to properly implement CSRF protection mechanisms on one or more of its administrative forms. This oversight allows an external attacker to craft malicious requests that, when executed by an authenticated administrator, inject persistent JavaScript code into the plugin's stored data.

The absence of nonce verification or other anti-CSRF tokens means the plugin cannot distinguish between legitimate administrative actions and forged requests originating from malicious third-party sites. When combined with insufficient output encoding, the injected content is stored and later rendered without sanitization, creating a Stored XSS condition.

Root Cause

The root cause of this vulnerability is twofold: first, the KBucket plugin does not implement proper CSRF protections such as WordPress nonces on state-changing operations; second, user-supplied input is stored in the database and subsequently rendered in the browser without adequate sanitization or output encoding. This dual failure allows the CSRF attack to successfully inject malicious scripts that persist and execute for all users viewing the affected content.

Attack Vector

The attack requires social engineering to lure an authenticated WordPress administrator to visit a malicious webpage controlled by the attacker. This page contains a hidden form or JavaScript that automatically submits a forged request to the vulnerable KBucket plugin endpoint. Since the administrator's browser automatically includes their authentication cookies, the malicious request is processed as legitimate. The payload—typically malicious JavaScript—is then stored in the WordPress database and executed whenever the affected content is viewed.

The attack flow involves the attacker hosting a page with an auto-submitting form targeting the vulnerable KBucket endpoint. When an authenticated admin visits this page, their browser submits the CSRF payload containing XSS code. The plugin stores this malicious input without validation, and subsequent page loads render the stored XSS payload to all visitors.

Detection Methods for CVE-2025-24562

Indicators of Compromise

• Unexpected JavaScript code or <script> tags appearing in KBucket plugin data or settings
• Suspicious outbound network requests from visitor browsers to unknown external domains
• Administrator reports of unexpected redirects or pop-ups when viewing KBucket content
• Modified plugin settings or content without corresponding admin activity in WordPress logs

Detection Strategies

• Review WordPress database entries associated with KBucket for any stored HTML or JavaScript that was not intentionally added
• Implement Content Security Policy (CSP) headers to detect and block unauthorized inline script execution
• Monitor WordPress audit logs for administrative changes to KBucket settings that correlate with suspicious browsing activity
• Use web application firewalls (WAF) to detect and block CSRF and XSS attack patterns

Monitoring Recommendations

• Enable and regularly review WordPress activity logging for all administrative plugin interactions
• Configure browser-based security monitoring to alert on CSP violations indicating XSS attempts
• Implement real-time file integrity monitoring on WordPress database tables related to KBucket
• Deploy endpoint detection solutions capable of identifying malicious JavaScript execution patterns

How to Mitigate CVE-2025-24562

Immediate Actions Required

• Disable the KBucket plugin immediately if it is not critical to site operations
• Review all KBucket-stored content for evidence of injected malicious scripts and remove any suspicious entries
• Ensure all WordPress administrators are aware of the risk and avoid clicking links from untrusted sources while logged into WordPress
• Consider implementing a Web Application Firewall (WAF) rule to block suspicious POST requests to KBucket endpoints

Patch Information

This vulnerability affects KBucket versions through 4.1.6. Organizations should monitor the Patchstack Vulnerability Report for updates on available patches. Check the WordPress plugin repository for any security updates released for KBucket versions newer than 4.1.6 and apply them immediately when available.

Workarounds

• Restrict access to WordPress administrative functions using IP whitelisting or VPN requirements
• Implement browser-level protections by configuring strict Content Security Policy headers that prevent inline script execution
• Use WordPress security plugins that provide additional CSRF protection layers for vulnerable plugins
• Limit the number of users with administrative access to reduce the attack surface for CSRF-based attacks

Administrators should configure additional security headers in their web server configuration to provide defense-in-depth. Adding X-Content-Type-Options: nosniff, X-Frame-Options: SAMEORIGIN, and a strict Content Security Policy can help mitigate the impact of successful XSS injection attempts while awaiting a vendor patch.