CVE-2025-1562: FunnelKit Automations Auth Bypass Vulnerability

CVE-2025-1562 Overview

The FunnelKit Automations plugin for WordPress (also known as "Recover WooCommerce Cart Abandonment, Newsletter, Email Marketing, Marketing Automation By FunnelKit") contains a critical authorization bypass vulnerability that allows unauthenticated attackers to install arbitrary plugins on vulnerable WordPress sites. The vulnerability exists due to a missing capability check on the install_or_activate_addon_plugins() function combined with a weak nonce hash implementation in all versions up to and including 3.5.3.

Critical Impact

Unauthenticated attackers can leverage this vulnerability to install malicious plugins, potentially achieving full site compromise including remote code execution, data theft, and persistent backdoor access.

Affected Products

• FunnelKit Automations (wp-marketing-automations) versions up to and including 3.5.3
• WordPress sites running vulnerable FunnelKit Automations plugin
• WooCommerce stores utilizing FunnelKit for cart abandonment and marketing automation

Discovery Timeline

• 2025-06-18 - CVE-2025-1562 published to NVD
• 2025-07-09 - Last updated in NVD database

Technical Details for CVE-2025-1562

Vulnerability Analysis

This vulnerability is classified as CWE-862 (Missing Authorization), a broken access control flaw that enables unauthenticated attackers to perform privileged operations. The vulnerable install_or_activate_addon_plugins() function lacks proper capability checks that should verify whether the requesting user has administrative privileges to install plugins. WordPress normally restricts plugin installation to users with the install_plugins capability, but this function bypasses that security control entirely.

The weakness is compounded by a weak nonce hash implementation. WordPress nonces (number used once) are designed to protect against CSRF attacks and unauthorized actions, but when implemented with predictable or weak hashing, attackers can potentially forge valid nonces or bypass the verification altogether. This combination of missing authorization and weak nonce protection creates a direct path for remote exploitation without any authentication requirements.

Root Cause

The root cause is a fundamental authorization design flaw in the install_or_activate_addon_plugins() function within the FunnelKit Automations plugin. The function fails to implement WordPress's standard capability checking mechanisms (such as current_user_can('install_plugins')) before executing plugin installation operations. Additionally, the nonce validation uses a weak hash that can be predicted or bypassed, eliminating the secondary protection layer that would normally prevent unauthorized access to administrative functions.

Attack Vector

The attack is network-accessible and requires no authentication or user interaction. An attacker can send crafted HTTP requests directly to the vulnerable endpoint, bypassing both authentication and authorization controls. The attack flow typically involves:

1. Identifying a WordPress site running a vulnerable version of FunnelKit Automations
2. Crafting a malicious request to the install_or_activate_addon_plugins() endpoint
3. Exploiting the weak nonce hash to bypass CSRF protection
4. Specifying a malicious plugin (either from the WordPress repository or an external source) for installation
5. Activating the installed plugin to execute malicious code

The vulnerability affects the plugin's REST API and admin AJAX handlers, as evidenced by the patched files including class-bwfan-api-base.php and class-bwfan-api-loader.php. For detailed technical analysis, refer to the Wordfence Vulnerability Report.

Detection Methods for CVE-2025-1562

Indicators of Compromise

• Unexpected plugins installed on WordPress sites, particularly those with suspicious names or from unknown developers
• Unusual HTTP POST requests to FunnelKit Automations API endpoints from external IP addresses
• New plugin activations in WordPress audit logs without corresponding administrator actions
• Modified files in /wp-content/plugins/ directory with recent timestamps not matching maintenance windows

Detection Strategies

• Monitor WordPress database wp_options table for unauthorized plugin additions in the active_plugins option
• Implement Web Application Firewall (WAF) rules to detect and block suspicious requests to FunnelKit API endpoints
• Review web server access logs for POST requests to /wp-json/ or admin-ajax.php endpoints associated with plugin installation actions
• Deploy file integrity monitoring to detect new or modified files in the WordPress plugins directory

Monitoring Recommendations

• Enable WordPress debug logging and monitor for plugin installation events from non-administrative sessions
• Configure SIEM alerts for multiple plugin installation attempts within short time windows
• Implement real-time monitoring of the wp-content/plugins/ directory for new subdirectories or file changes
• Monitor outbound network connections from WordPress for communication with known malicious infrastructure

How to Mitigate CVE-2025-1562

Immediate Actions Required

• Update FunnelKit Automations plugin to the latest patched version immediately
• Audit all installed plugins on affected WordPress sites for unauthorized additions
• Review WordPress user accounts for any newly created administrator accounts
• Implement a Web Application Firewall (WAF) with rules to block unauthorized plugin installation attempts

Patch Information

FunnelKit has released patches addressing this vulnerability in changeset 3305437. The patches modify capability checks and nonce handling in three key files: class-bwfan-admin.php, class-bwfan-api-base.php, and class-bwfan-api-loader.php. Site administrators should update to the latest version of the plugin through the WordPress admin dashboard or by downloading directly from the WordPress plugin repository. Review the WordPress Admin Class Changeset for patch details.

Workarounds

• Temporarily disable the FunnelKit Automations plugin until the patch can be applied
• Restrict access to WordPress admin endpoints using .htaccess rules or server-level IP allowlisting
• Implement additional authentication layers (such as HTTP Basic Auth) on the WordPress admin area
• Use security plugins to enforce strict capability checks on all plugin installation actions

# Temporary .htaccess mitigation to restrict API access
# Add to WordPress root .htaccess file
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{REQUEST_URI} ^/wp-json/funnelkit/ [OR]
RewriteCond %{REQUEST_URI} ^/wp-admin/admin-ajax.php
RewriteCond %{QUERY_STRING} action=bwfan [NC]
RewriteCond %{REMOTE_ADDR} !^(YOUR_ADMIN_IP)$
RewriteRule .* - [F,L]
</IfModule>