CVE-2025-47601: MaxiBlocks Privilege Escalation Flaw

CVE-2025-47601 Overview

CVE-2025-47601 is a missing authorization vulnerability in the MaxiBlocks WordPress plugin developed by Christiaan Pieterse. The flaw affects all versions of MaxiBlocks up to and including 2.1.0. Authenticated attackers with low-privilege accounts can perform arbitrary option updates against the WordPress site. Successful exploitation enables privilege escalation to administrator. The weakness is classified under CWE-862: Missing Authorization.

Critical Impact
An authenticated low-privilege user can escalate to administrator by updating arbitrary WordPress options, leading to full site takeover.

Affected Products

MaxiBlocks WordPress plugin versions up to and including 2.1.0
WordPress sites running the vulnerable MaxiBlocks plugin with subscriber-level or higher accounts enabled
Multisite WordPress installations using MaxiBlocks for page building

Discovery Timeline

2025-06-07 - CVE-2025-47601 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-47601

Vulnerability Analysis

The vulnerability resides in MaxiBlocks plugin endpoints that update WordPress options without verifying the caller's capabilities. WordPress options control core site behavior, including the default_role setting that governs the role assigned to newly registered users. By updating default_role to administrator, an attacker turns the registration flow into an administrator factory.

The plugin exposes AJAX or REST handlers that accept option name and value parameters from authenticated users. These handlers lack current_user_can() checks and nonce verification scoped to privileged operations. Any authenticated session, including subscriber accounts, can therefore invoke the option update path.

This class of bug appears repeatedly in WordPress plugins because authors conflate authentication with authorization. A logged-in user is not necessarily authorized for administrative actions. The MaxiBlocks handler treats the two as equivalent.

Root Cause

The root cause is the absence of capability checks (current_user_can('manage_options')) and option-name allow-listing inside the affected handler. The plugin trusts authenticated input and forwards it directly to update_option().

Attack Vector

An attacker first obtains any authenticated WordPress account on the target site. On sites with open user registration this is trivial. The attacker then sends a crafted request to the vulnerable MaxiBlocks endpoint specifying default_role as the option and administrator as the value. After the update succeeds, the attacker registers a new account that is automatically promoted to administrator, or modifies other sensitive options such as users_can_register and siteurl.

No user interaction is required from existing administrators. The attack is fully remote over the network. See the Patchstack Vulnerability Report for additional technical detail.

Detection Methods for CVE-2025-47601

Indicators of Compromise

Unexpected changes to the default_role option, particularly values of administrator or editor in the wp_options table
New WordPress user accounts created with administrator privileges shortly after subscriber-level logins
POST requests to MaxiBlocks AJAX or REST endpoints originating from low-privilege session cookies
Modifications to users_can_register, siteurl, or home options with no corresponding admin audit log entry

Detection Strategies

Inventory all WordPress installations and flag any running MaxiBlocks <= 2.1.0
Query the wp_options table directly and compare default_role and related values against a known-good baseline
Review web server access logs for authenticated requests to admin-ajax.php or /wp-json/maxi-blocks/* paths followed by privilege changes
Correlate user registration events with prior option-update requests from the same IP or session

Monitoring Recommendations

Enable WordPress audit logging to record option changes and user role assignments with timestamps and source IPs
Forward WordPress and web server logs to a centralized SIEM for cross-correlation across registration, login, and option-update events
Alert on any write to default_role that does not originate from an authenticated administrator session
Monitor for sudden creation of administrator accounts outside change windows

How to Mitigate CVE-2025-47601

Immediate Actions Required

Update MaxiBlocks to the patched release as published by the vendor; do not run versions <= 2.1.0 in production
Audit the wp_users and wp_usermeta tables for unauthorized administrator accounts and remove them
Reset passwords for all administrator and editor accounts and rotate WordPress salts in wp-config.php
Disable open user registration (users_can_register = 0) until the plugin is updated

Patch Information

Refer to the Patchstack Vulnerability Report for the fixed version reference. Apply the vendor patch through the WordPress plugin updater or by replacing the plugin files manually.

Workarounds

Deactivate and remove the MaxiBlocks plugin until the patched version is deployed
Restrict access to /wp-admin/admin-ajax.php and the plugin's REST routes via a web application firewall rule that blocks non-administrator callers
Set default_role to subscriber and monitor for unauthorized changes
Enforce least privilege by removing unused subscriber and contributor accounts that could be leveraged for exploitation

bash

# Configuration example: harden WordPress while patching
wp option update users_can_register 0
wp option update default_role subscriber
wp plugin deactivate maxi-blocks
wp user list --role=administrator --fields=ID,user_login,user_email,user_registered