CVE-2025-6042

Executive Summary

CVE-2025-6042 is a privilege escalation vulnerability in the Lisfinity Core WordPress plugin (by Pebas), affecting all versions up to and including 1.4.0. The plugin incorrectly assigns the editor role by default and fails to restrict API access, allowing authenticated users with editor-level privileges to escalate their capabilities. This vulnerability is particularly dangerous when chained with CVE-2025-6038, enabling an attacker to gain full administrative control over the WordPress site. The vulnerability is currently unpatched, and no official fix has been released by the vendor.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository and third-party marketplaces. Users who have installed the Lisfinity Core plugin as part of the Pebas Lisfinity theme are at risk. Since the plugin is unpatched, the supply chain risk is elevated, and users must rely on manual mitigation or removal.

CVSS Breakdown & Threat Level

• CVSS Score: 7.3 (High)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: Low (PR:L) – requires an editor-level account
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: High (C:H)
• Integrity Impact: High (I:H)
• Availability Impact: None (A:N)

Threat Level: High. The vulnerability is easy to exploit once an attacker has editor credentials, and it can lead to full site compromise when combined with CVE-2025-6038.

Deep Dive & Mechanics

The Lisfinity Core plugin, part of the Pebas Lisfinity WordPress theme, is designed to manage property listings and user roles. The vulnerability stems from two key issues:

1. Default Role Assignment: The plugin assigns the editor role to users upon registration or via API calls, rather than the standard subscriber role. This grants excessive capabilities by default.
2. Unrestricted API Access: The plugin exposes REST API endpoints that allow editors to modify user roles, create new users, or update their own capabilities. The plugin attempts to limit these actions but fails to enforce restrictions on API calls, allowing editors to escalate to administrator.

When chained with CVE-2025-6038 (which likely provides initial access or further privilege escalation), an attacker can:

• Authenticate as an editor.
• Use the plugin's API to modify their role to administrator.
• Gain full control over the WordPress site.

The vulnerability is present in all versions up to and including 1.4.0. No patch is available.

Vulnerable vs. Patched Code

Since no patch is available, the vulnerable code is the only reference. The plugin likely contains a function similar to:

// Vulnerable code in Lisfinity Core <= 1.4.0
add_action('rest_api_init', function () {
    register_rest_route('lisfinity/v1', '/user/update', array(
        'methods' => 'POST',
        'callback' => 'lisfinity_update_user_role',
        'permission_callback' => function () {
            return current_user_can('edit_posts'); // Only checks for editor capability
        }
    ));
});

function lisfinity_update_user_role($request) {
    $user_id = get_current_user_id();
    $new_role = $request->get_param('role');
    // No capability check for role assignment
    $user = new WP_User($user_id);
    $user->set_role($new_role);
    return new WP_REST_Response(array('success' => true), 200);
}

A patched version would:

• Restrict the API endpoint to administrators only.
• Validate that the requested role is within allowed roles (e.g., only subscriber or editor).
• Use nonces and additional capability checks.

Exploitation & Lab Setup

Red Team

Prerequisites:

• A WordPress site with Lisfinity Core <= 1.4.0 installed.
• Valid editor-level credentials (e.g., editor:password).

Exploitation Steps:

1. Authenticate to the WordPress site as an editor.
2. Identify the vulnerable API endpoint (e.g., /wp-json/lisfinity/v1/user/update).
3. Send a POST request to escalate privileges:

curl -X POST https://target.com/wp-json/lisfinity/v1/user/update \
  -H "Content-Type: application/json" \
  -H "Cookie: wordpress_logged_in_<hash>=<session_cookie>" \
  -d '{"role": "administrator"}'

4. Verify the new role by accessing /wp-admin/ and confirming admin capabilities.

Chaining with CVE-2025-6038: If CVE-2025-6038 provides initial access (e.g., SQL injection to extract editor credentials), use those credentials to perform the above steps.

Blue Team

Detection & Response:

• Monitor for unusual API calls to /wp-json/lisfinity/v1/user/update with role changes.
• Alert on any user role escalation from editor to administrator.
• Review user registration logs for unexpected editor accounts.

Honeypot Setup:

• Deploy a fake WordPress instance with Lisfinity Core and monitor API traffic.
• Log all role change attempts and block IPs after 3 failed attempts.

Indicators of Compromise (IOCs)

• File Indicators:

  • Presence of /wp-content/plugins/lisfinity-core/ directory.
  • Modified wp_users table entries with wp_capabilities containing administrator.

• Network Indicators:

  • POST requests to /wp-json/lisfinity/v1/user/update with JSON body containing "role": "administrator".
  • Unusual user agent strings (e.g., curl/7.x).

• Log Indicators:

  • WordPress debug log entries showing role changes.
  • Apache/Nginx access logs with POST /wp-json/lisfinity/v1/user/update and 200 response.

Detection Engineering

YARA Rule

rule Detect_Lisfinity_Core_PrivEsc {
    meta:
        description = "Detects Lisfinity Core plugin files vulnerable to CVE-2025-6042"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-6042"
    strings:
        $api_route = "lisfinity/v1/user/update"
        $role_set = "set_role"
        $permission_callback = "current_user_can('edit_posts')"
    condition:
        all of them
}

Sigma Rule

title: Lisfinity Core Privilege Escalation via API
id: 8a9b3c4d-5e6f-7a8b-9c0d-1e2f3a4b5c6d
status: experimental
description: Detects attempts to exploit CVE-2025-6042 by escalating user role via Lisfinity API
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: '/wp-json/lisfinity/v1/user/update'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin actions (rare)
level: high

Suricata Rule

alert http $HOME_NET any -> $EXTERNAL_NET any (
    msg:"CVE-2025-6042 Lisfinity Core Privilege Escalation Attempt";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"/wp-json/lisfinity/v1/user/update";
    http_uri;
    content:"\"role\": \"administrator\"";
    http_client_body;
    sid:1000001;
    rev:1;
    reference:cve,2025-6042;
    classtype:attempted-admin;
)

Remediation & Mitigation

Since no patch is available, the following mitigations are recommended:

1. Immediate Action:

   • Disable or remove the Lisfinity Core plugin until a patch is released.
   • If the plugin is essential, restrict access to the API endpoint via .htaccess or a Web Application Firewall (WAF).

2. Short-term:

   • Implement a custom WordPress filter to block role escalation via the plugin's API:

     add_filter('rest_pre_dispatch', function($result, $server, $request) {
         if (strpos($request->get_route(), 'lisfinity/v1/user/update') !== false) {
             return new WP_Error('rest_forbidden', 'Access denied', array('status' => 403));
         }
         return $result;
     }, 10, 3);
     

   • Monitor user role changes and set up alerts.

3. Long-term:

   • Contact the vendor (Pebas) for a patch or consider migrating to an alternative theme/plugin.
   • Conduct a security audit of all WordPress plugins and themes.

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