CVE-2025-39374: Best Posts Summary CSRF Vulnerability

CVE-2025-39374 Overview

CVE-2025-39374 is a Cross-Site Request Forgery (CSRF) vulnerability in the WordPress Best Posts Summary plugin (developed by aseem1234) that enables attackers to perform Stored Cross-Site Scripting (XSS) attacks. This chained vulnerability allows unauthenticated attackers to trick authenticated administrators into unknowingly submitting malicious requests that inject persistent JavaScript code into the WordPress site.

Critical Impact

This CSRF-to-Stored-XSS attack chain allows attackers to execute arbitrary JavaScript in the context of administrator sessions, potentially leading to complete site compromise, credential theft, and malicious content injection affecting all site visitors.

Affected Products

• Best Posts Summary WordPress Plugin version 1.0 and earlier
• WordPress installations using the best-posts-summary plugin

Discovery Timeline

• 2025-05-19 - CVE-2025-39374 published to NVD
• 2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-39374

Vulnerability Analysis

This vulnerability combines two distinct attack techniques: Cross-Site Request Forgery (CSRF) and Stored Cross-Site Scripting (XSS). The Best Posts Summary plugin fails to implement proper CSRF token validation on administrative form submissions, allowing attackers to craft malicious requests that administrators unknowingly execute when visiting attacker-controlled pages.

The attack requires user interaction—specifically, an authenticated administrator must be tricked into clicking a malicious link or visiting a compromised webpage while logged into their WordPress dashboard. Once the forged request is processed, malicious JavaScript payload is stored in the WordPress database and subsequently rendered to all users viewing affected pages.

The vulnerability is classified under CWE-352 (Cross-Site Request Forgery), recognizing the root cause as missing or improper validation of anti-CSRF tokens in the plugin's administrative interface.

Root Cause

The Best Posts Summary plugin lacks proper nonce verification on forms that handle user-supplied input. WordPress provides built-in functions (wp_nonce_field(), wp_verify_nonce(), and check_admin_referer()) for CSRF protection, but the plugin fails to implement these security controls. Additionally, the plugin does not properly sanitize or escape user input before storing it in the database or rendering it in HTML output, enabling the stored XSS component of this attack chain.

Attack Vector

The attack is network-based and requires an attacker to craft a malicious HTML page containing a hidden form that auto-submits to the vulnerable plugin endpoint. When an authenticated WordPress administrator visits this malicious page, the forged request is sent with the administrator's cookies, bypassing the missing CSRF protections. The payload persists in the database and executes whenever the affected page or widget is rendered.

A typical attack scenario involves:

1. Attacker identifies a WordPress site using the vulnerable Best Posts Summary plugin
2. Attacker crafts a malicious page with an auto-submitting form targeting the plugin's administrative endpoint
3. Attacker tricks an administrator into visiting the malicious page (via phishing, social engineering, or watering hole attacks)
4. The forged request injects malicious JavaScript into stored plugin settings
5. The stored XSS payload executes for all users viewing affected content

For detailed technical information, see the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2025-39374

Indicators of Compromise

• Unexpected JavaScript code in Best Posts Summary plugin settings or database entries
• Suspicious POST requests to WordPress admin endpoints containing <script> tags or JavaScript event handlers
• Unusual administrator activity patterns, especially settings changes without corresponding admin session activity
• External domains referenced in plugin configuration that were not intentionally configured

Detection Strategies

• Monitor WordPress admin-ajax.php and plugin settings pages for POST requests originating from external referers
• Implement Content Security Policy (CSP) headers to detect and block unauthorized script execution
• Review plugin settings and database tables associated with Best Posts Summary for injected script content
• Deploy web application firewall (WAF) rules to detect CSRF and XSS attack patterns

Monitoring Recommendations

• Enable WordPress audit logging to track all administrative actions and settings changes
• Configure alerts for plugin settings modifications outside normal administrative workflows
• Monitor server access logs for suspicious patterns of requests to administrative endpoints
• Implement integrity monitoring on WordPress database tables to detect unauthorized content modifications

How to Mitigate CVE-2025-39374

Immediate Actions Required

• Deactivate and remove the Best Posts Summary plugin (best-posts-summary) from all WordPress installations immediately
• Audit plugin settings and database entries for any injected malicious content
• Review administrator accounts for signs of compromise and reset credentials if necessary
• Clear any cached pages that may contain injected content

Patch Information

As of the last modification date (2026-04-23), the Best Posts Summary plugin version 1.0 and earlier remain vulnerable. Website administrators should check the Patchstack vulnerability database for updates on patch availability and remediation guidance.

Workarounds

• Remove the Best Posts Summary plugin entirely until a patched version is available
• Implement a Web Application Firewall (WAF) with CSRF and XSS protection rules
• Restrict administrative dashboard access to trusted IP addresses only
• Educate administrators about phishing risks and avoiding untrusted links while logged into WordPress

# WordPress CLI command to deactivate the vulnerable plugin
wp plugin deactivate best-posts-summary --path=/var/www/html/wordpress

# Remove the plugin entirely
wp plugin delete best-posts-summary --path=/var/www/html/wordpress

# Check for any suspicious content in plugin-related database options
wp db query "SELECT * FROM wp_options WHERE option_name LIKE '%best_posts_summary%';" --path=/var/www/html/wordpress