CVE-2025-66127

Executive Summary

CVE-2025-66127 is a Missing Authorization vulnerability in the Essential Real Estate WordPress plugin by G5theme, affecting versions through 5.3.2. This flaw allows unauthenticated attackers to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access or privilege escalation within the WordPress ecosystem. The vulnerability has a CVSS score of 5.3 (Medium) and an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public proof-of-concept (PoC) or exploit code has been released, and no official patch is available. As a WordPress plugin issue, the vulnerability resides entirely within the plugin’s codebase and does not affect the underlying web server (Apache/Nginx).

Supply Chain & Package Security

This vulnerability affects the Essential Real Estate WordPress plugin, distributed via the WordPress plugin repository and third-party marketplaces. Organizations using this plugin should treat it as a supply chain risk, as the vendor has not provided a patch. The plugin is not available on NPM, PyPI, Go, or Ruby ecosystems.

CVSS Breakdown & Threat Level

• CVSS Score: 5.3 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: None
• Availability Impact: None

The vulnerability allows unauthenticated network access to exploit missing authorization checks, leading to limited information disclosure. The low EPSS score (0.0%) suggests active exploitation is not widespread, but the lack of a patch increases long-term risk.

Deep Dive & Mechanics

The Essential Real Estate plugin (slug: essential-real-estate) provides real estate listing functionality for WordPress sites. The vulnerability stems from missing authorization checks in AJAX handlers or REST API endpoints that process sensitive data. Specifically, the plugin fails to verify user capabilities before executing actions such as viewing private listings, modifying property data, or accessing administrative functions.

Root Cause: The plugin uses wp_ajax_* and wp_ajax_nopriv_* hooks without proper capability checks (e.g., current_user_can()). This allows unauthenticated users to trigger actions intended only for authenticated users with specific roles (e.g., edit_posts, manage_options).

Attack Vector: An attacker sends crafted HTTP requests to the vulnerable endpoints, bypassing access controls. For example, a request to /wp-admin/admin-ajax.php?action=ere_get_property_details&property_id=123 might return sensitive property data without authentication.

Impact: Unauthorized access to private property listings, customer data, or administrative settings. In some configurations, this could lead to privilege escalation if the plugin exposes user management or configuration endpoints.

Vulnerable vs. Patched Code

Since no official patch exists, the following illustrates a typical vulnerable pattern and a hypothetical fix.

Vulnerable Code (PHP):

add_action('wp_ajax_nopriv_ere_get_property', 'ere_get_property_handler');
function ere_get_property_handler() {
    $property_id = intval($_GET['property_id']);
    $property = get_post($property_id);
    echo json_encode($property);
    wp_die();
}

Patched Code (Hypothetical):

add_action('wp_ajax_ere_get_property', 'ere_get_property_handler');
add_action('wp_ajax_nopriv_ere_get_property', 'ere_get_property_handler');
function ere_get_property_handler() {
    // Check if user is logged in and has required capability
    if (!is_user_logged_in() || !current_user_can('edit_posts')) {
        wp_die('Unauthorized', 403);
    }
    $property_id = intval($_GET['property_id']);
    $property = get_post($property_id);
    echo json_encode($property);
    wp_die();
}

The patched version restricts access to authenticated users with the edit_posts capability and removes the nopriv hook for sensitive actions.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress site with Essential Real Estate plugin <= 5.3.2
• Network access to the target

Exploitation Steps:

1. Identify vulnerable endpoints by analyzing plugin source code or using fuzzing tools.
2. Send a crafted HTTP request to an AJAX endpoint without authentication:

   curl -X POST "http://target/wp-admin/admin-ajax.php" \
        -d "action=ere_get_property_details&property_id=1"
   

3. If the endpoint returns sensitive data (e.g., property details, user info), the vulnerability is confirmed.

Example Request (Unauthenticated):

POST /wp-admin/admin-ajax.php HTTP/1.1
Host: target
Content-Type: application/x-www-form-urlencoded

action=ere_get_property_details&property_id=1

Expected Response (Vulnerable):

{
  "id": 1,
  "title": "Luxury Villa",
  "price": "500000",
  "owner_email": "owner@example.com"
}

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual AJAX requests to admin-ajax.php with action parameters related to Essential Real Estate (e.g., ere_*).
• Look for requests from unauthenticated users (no Cookie header or invalid nonce).
• Use the Sigma rule below to detect exploitation attempts.

Defense:

• Disable the plugin until a patch is available.
• Implement a Web Application Firewall (WAF) rule to block unauthenticated requests to admin-ajax.php with action parameters starting with ere_.
• Restrict access to admin-ajax.php using .htaccess or server-level rules.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wp-admin/admin-ajax.php with action=ere_* parameters from unauthenticated sources.
  • Unusual response sizes containing JSON data with property or user details.
• File IOCs:
  • Modified plugin files (e.g., essential-real-estate/includes/class-ere-ajax.php) with unauthorized changes.
• Log IOCs:
  • WordPress debug logs showing wp_ajax_nopriv_* calls without nonce validation.
  • Web server access logs with repeated POST /wp-admin/admin-ajax.php entries from the same IP.

Detection Engineering

YARA Rule

rule Detect_Essential_Real_Estate_Exploit {
    meta:
        description = "Detects exploitation attempts against CVE-2025-66127 in Essential Real Estate plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-66127"
    strings:
        $ajax_action = "action=ere_" nocase
        $admin_ajax = "admin-ajax.php" nocase
        $property_id = "property_id=" nocase
    condition:
        $admin_ajax and $ajax_action and $property_id
}

Sigma Rule

title: Detection of CVE-2025-66127 Exploitation Attempts
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects unauthenticated AJAX requests targeting Essential Real Estate plugin
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=ere_'
    condition: selection
falsepositives:
    - Legitimate authenticated requests from site administrators
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-66127 Essential Real Estate Unauthenticated AJAX Access"; flow:to_server,established; content:"POST"; http_method; content:"admin-ajax.php"; http_uri; content:"action=ere_"; http_client_body; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical to operations.
2. Apply a virtual patch using a WAF to block unauthenticated requests to admin-ajax.php with action=ere_* parameters.
3. Monitor logs for exploitation attempts using the provided detection rules.

Long-Term Fix:

• Since no official patch exists, consider migrating to an alternative real estate plugin with active security support.
• If the plugin is essential, implement custom code fixes by adding capability checks to all AJAX handlers (see patched code example).
• Regularly audit WordPress plugins for missing authorization vulnerabilities.

Workaround:

• Restrict access to wp-admin/admin-ajax.php using .htaccess:

  <Files "admin-ajax.php">
      Require all denied
      Require ip 127.0.0.1
  </Files>
  

  (Note: This may break legitimate AJAX functionality; use with caution.)

Valters IT