CVE-2025-2111: Insert Headers And Footers CSRF Vulnerability

CVE-2025-2111 Overview

The Insert Headers And Footers plugin for WordPress contains a Cross-Site Request Forgery (CSRF) vulnerability in all versions up to and including 3.1.1. This vulnerability exists due to missing or incorrect nonce validation on the custom_plugin_set_option function, allowing unauthenticated attackers to update arbitrary options on WordPress sites through forged requests.

Critical Impact

Attackers can leverage this vulnerability to modify the default user registration role to administrator and enable user registration, potentially gaining full administrative access to vulnerable WordPress sites.

Affected Products

• Insert Headers And Footers WordPress Plugin versions up to and including 3.1.1
• WordPress sites with the WPBRIGADE_SDK__DEV_MODE constant set to true

Discovery Timeline

• 2025-04-19 - CVE-2025-2111 published to NVD
• 2026-04-15 - Last updated in NVD database

Technical Details for CVE-2025-2111

Vulnerability Analysis

This Cross-Site Request Forgery vulnerability stems from inadequate security controls in the plugin's option-setting functionality. The custom_plugin_set_option function fails to properly validate nonces, which are cryptographic tokens designed to prevent unauthorized cross-site request attacks. Without proper nonce verification, the plugin cannot distinguish between legitimate administrative actions and malicious forged requests.

The vulnerability requires a specific precondition: the WPBRIGADE_SDK__DEV_MODE constant must be set to true in the WordPress configuration. While this may limit exploitation in production environments, development or staging environments with this constant enabled are at significant risk.

Root Cause

The root cause of CVE-2025-2111 is the absence of proper nonce validation in the custom_plugin_set_option function within the plugin's debug functionality. The vulnerable code resides in the wpb-debug.php file within the WPB SDK library bundled with the plugin. Without nonce checks, the application cannot verify that option update requests originate from authenticated administrators through legitimate WordPress admin interfaces.

Attack Vector

The attack leverages the network-accessible nature of WordPress sites. An attacker crafts a malicious web page or link containing a forged request targeting the vulnerable function. When a logged-in site administrator visits the malicious page or clicks the link, their browser automatically sends the forged request to the WordPress site, executing the option change with the administrator's privileges.

The attack chain typically follows this pattern:

1. Attacker identifies a WordPress site running a vulnerable version of Insert Headers And Footers with WPBRIGADE_SDK__DEV_MODE enabled
2. Attacker crafts a malicious page containing a forged request to modify WordPress options
3. Attacker tricks a site administrator into visiting the malicious page (via phishing, social engineering, or malicious advertising)
4. The forged request executes, modifying the default_role option to administrator and enabling user registration
5. Attacker registers a new account on the target site, automatically receiving administrator privileges

Detection Methods for CVE-2025-2111

Indicators of Compromise

• Unexpected changes to WordPress user registration settings (user registration enabled when it was previously disabled)
• Modification of the default_role option to administrator without authorized administrative action
• New administrator accounts appearing on the site without legitimate creation
• Suspicious requests to plugin debug endpoints in web server access logs

Detection Strategies

• Monitor WordPress options table for unauthorized changes to users_can_register and default_role settings
• Implement web application firewall (WAF) rules to detect and block suspicious requests to plugin debug endpoints
• Enable and review WordPress security audit logs for option modifications
• Deploy SentinelOne Singularity to detect unauthorized changes to WordPress configuration files and database

Monitoring Recommendations

• Configure alerts for new administrator account creation on WordPress sites
• Implement regular audits of user accounts and privilege levels
• Monitor for the presence of WPBRIGADE_SDK__DEV_MODE constant in WordPress configurations
• Review web server logs for patterns consistent with CSRF attacks targeting the Insert Headers And Footers plugin

How to Mitigate CVE-2025-2111

Immediate Actions Required

• Update the Insert Headers And Footers plugin to a patched version immediately
• Verify that the WPBRIGADE_SDK__DEV_MODE constant is not set to true in production environments
• Audit WordPress user accounts for any unauthorized administrator accounts and remove them
• Review and reset WordPress options related to user registration (users_can_register, default_role)

Patch Information

A security patch addressing this vulnerability has been released. The fix can be reviewed in WordPress Changeset #3276361. Site administrators should update to the latest version of the Insert Headers And Footers plugin through the WordPress plugin repository. For detailed vulnerability analysis, refer to the Wordfence Vulnerability Analysis.

Workarounds

• Remove or set WPBRIGADE_SDK__DEV_MODE constant to false in wp-config.php or relevant configuration files
• Temporarily deactivate the Insert Headers And Footers plugin until a patch can be applied
• Implement additional CSRF protection through security plugins or web application firewalls
• Restrict administrator access to trusted IP addresses using .htaccess or server-level firewall rules

# Remove or disable dev mode in wp-config.php
# Ensure this line does NOT exist or is set to false:
# define('WPBRIGADE_SDK__DEV_MODE', true);

# To explicitly disable, add:
define('WPBRIGADE_SDK__DEV_MODE', false);