CVE-2025-46457: Wp Custom CMS Block CSRF Vulnerability

CVE-2025-46457 Overview

CVE-2025-46457 is a Cross-Site Request Forgery (CSRF) vulnerability affecting the WP Custom CMS Block WordPress plugin developed by Ahsanullah Akanda. This vulnerability enables attackers to leverage CSRF to inject and store malicious scripts (Stored XSS), creating a chained attack that can compromise website administrators and visitors alike.

Critical Impact

This CSRF-to-Stored-XSS vulnerability chain allows unauthenticated attackers to trick authenticated administrators into unknowingly executing malicious actions, leading to persistent script injection that affects all subsequent visitors to the compromised pages.

Affected Products

• WP Custom CMS Block plugin version 2.1 and earlier
• WordPress installations using vulnerable versions of wp-custom-cms-block
• Websites with administrators who may interact with attacker-controlled links

Discovery Timeline

• 2025-04-24 - CVE-2025-46457 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-46457

Vulnerability Analysis

This vulnerability represents a dangerous attack chain combining two distinct web application security flaws. The WP Custom CMS Block plugin fails to implement proper CSRF token validation on sensitive administrative actions. This oversight allows attackers to craft malicious requests that, when executed by an authenticated administrator, inject persistent JavaScript code into the WordPress database.

The Stored XSS component means that once the malicious payload is injected, it persists within the application and executes every time a user views the affected content. This differs from reflected XSS attacks that require direct user interaction with a malicious link for each execution.

The network-accessible attack vector combined with the requirement for user interaction (administrator clicking a malicious link) creates a moderate barrier to exploitation while still presenting significant risk in targeted attack scenarios.

Root Cause

The root cause stems from improper implementation of anti-CSRF protections within the plugin's form handling mechanisms. Specifically, the plugin does not verify that form submissions originate from legitimate administrative sessions using WordPress nonces or similar CSRF tokens. Additionally, the plugin fails to properly sanitize and escape user-supplied input before storing it in the database, enabling the stored XSS component of the attack chain.

Attack Vector

The attack follows a multi-stage exploitation path:

1. Reconnaissance: Attacker identifies a WordPress site using the vulnerable WP Custom CMS Block plugin
2. Payload Crafting: Attacker creates a malicious HTML page or link containing a hidden form that submits XSS payloads to the vulnerable plugin endpoint
3. Social Engineering: Attacker tricks an authenticated administrator into visiting the malicious page (via phishing email, malicious advertisement, or compromised website)
4. CSRF Exploitation: The administrator's browser automatically submits the hidden form, leveraging their active session to bypass authentication
5. XSS Injection: The malicious script is stored in the WordPress database
6. Persistent Execution: The XSS payload executes for all users who subsequently view the affected content, potentially stealing session cookies, performing actions on behalf of users, or redirecting to phishing pages

Detection Methods for CVE-2025-46457

Indicators of Compromise

• Unexpected JavaScript code in CMS block content or database entries associated with the wp-custom-cms-block plugin
• Administrator session cookies or credentials appearing in attacker-controlled server logs
• Unusual outbound requests from WordPress pages to external domains
• Reports from users about unexpected redirects, pop-ups, or behavior on pages using custom CMS blocks

Detection Strategies

• Review WordPress database tables for suspicious script tags or event handlers in content managed by the WP Custom CMS Block plugin
• Monitor web application firewall (WAF) logs for XSS payload patterns targeting plugin endpoints
• Implement Content Security Policy (CSP) headers and monitor for policy violations that may indicate injected scripts
• Audit plugin source code for missing nonce verification in form handlers

Monitoring Recommendations

• Enable detailed logging for administrative actions within WordPress to detect anomalous changes to CMS block content
• Deploy real-time alerting for new JavaScript content appearing in database fields that should contain only text or HTML
• Monitor for unusual referrer patterns in access logs that may indicate CSRF attacks originating from external domains

How to Mitigate CVE-2025-46457

Immediate Actions Required

• Disable or remove the WP Custom CMS Block plugin until a patched version is available
• Review all existing CMS block content for injected scripts and remove any malicious code
• Rotate administrator credentials and invalidate active sessions as a precaution
• Implement or verify Web Application Firewall rules to block common XSS payloads

Patch Information

No official patch information is currently available from the vendor. Users should monitor the Patchstack security advisory for updates on remediation status. Consider replacing the plugin with an alternative that has active security maintenance.

Workarounds

• Disable the plugin entirely by removing or renaming the wp-custom-cms-block plugin directory
• Implement strict Content Security Policy headers to prevent execution of inline scripts
• Use WordPress security plugins that add CSRF protection to plugin forms
• Restrict administrative access to trusted IP addresses to reduce the likelihood of successful CSRF exploitation

# Disable plugin via command line
wp plugin deactivate wp-custom-cms-block --path=/var/www/html/wordpress

# Add CSP header to Apache configuration to mitigate XSS impact
# Add to .htaccess or Apache config:
# Header set Content-Security-Policy "default-src 'self'; script-src 'self'"