CVE-2025-63077

Executive Summary

CVE-2025-63077 is a Missing Authorization vulnerability in the Happy Addons for Elementor WordPress plugin, developed by HappyMonster. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access or functionality exposure. The vulnerability affects all versions of the plugin up to and including 3.20.3. As of this report, no official patch has been released, and no public proof-of-concept (PoC) or exploit code is available. The EPSS score is 0.0%, indicating a very low probability of active exploitation in the wild at this time, but the risk remains due to the widespread use of Elementor and its add-ons.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem and the Happy Addons for Elementor plugin. It is not related to NPM, PyPI, Go, or Ruby packages. The plugin is distributed through the official WordPress plugin repository and third-party marketplaces. Users are advised to monitor the plugin's update channel for a patched version.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N) – The vulnerability can be exploited remotely.
• Attack Complexity: Low (AC:L) – No special conditions are required.
• Privileges Required: None (PR:N) – No authentication is needed.
• User Interaction: None (UI:N) – No user action is required.
• Scope: Unchanged (S:U) – The impact is confined to the vulnerable component.
• Confidentiality Impact: Low (C:L) – Limited unauthorized data access is possible.
• Integrity Impact: None (I:N) – No data modification is possible.
• Availability Impact: None (A:N) – No denial of service is expected.

Threat Level: Medium. While the CVSS score is moderate, the lack of a patch and the plugin's popularity increase the risk. The vulnerability is classified under MITRE ATT&CK Tactic T1190 (Exploit Public-Facing Application).

Deep Dive & Mechanics

The vulnerability resides in the Happy Addons for Elementor plugin's access control mechanisms. The plugin likely exposes certain REST API endpoints or AJAX actions that are intended to be restricted to authenticated users with specific roles (e.g., administrators or editors). However, due to a missing authorization check, these endpoints are accessible to unauthenticated users.

Root Cause: The plugin fails to properly validate user permissions before executing sensitive operations. This is a classic CWE-862: Missing Authorization flaw. The vulnerable code likely uses a function like wp_ajax_nopriv_* without a corresponding capability check, or it relies on a nonce that can be bypassed.

Attack Vector: An attacker can send crafted HTTP requests to the WordPress site's REST API or admin-ajax.php endpoint, targeting the vulnerable Happy Addons functionality. For example, if the plugin exposes an endpoint to retrieve widget settings or user data, an unauthenticated request could return sensitive information.

Impact: Successful exploitation could lead to:

• Unauthorized access to plugin configuration data.
• Exposure of non-public widget settings or templates.
• Potential information disclosure that could aid further attacks.

Vulnerable vs. Patched Code

Since no patch is available, a direct comparison cannot be made. However, based on the vulnerability type, the following hypothetical example illustrates the issue:

Vulnerable Code (PHP):

add_action( 'wp_ajax_nopriv_happy_get_widget_data', 'happy_get_widget_data' );
function happy_get_widget_data() {
    // No capability check
    $widget_id = $_GET['widget_id'];
    $data = get_option( 'happy_widget_' . $widget_id );
    wp_send_json_success( $data );
}

Patched Code (Hypothetical):

add_action( 'wp_ajax_happy_get_widget_data', 'happy_get_widget_data' );
add_action( 'wp_ajax_nopriv_happy_get_widget_data', 'happy_get_widget_data' );
function happy_get_widget_data() {
    // Check if user has required capability
    if ( ! current_user_can( 'manage_options' ) ) {
        wp_die( 'Unauthorized' );
    }
    $widget_id = sanitize_text_field( $_GET['widget_id'] );
    $data = get_option( 'happy_widget_' . $widget_id );
    wp_send_json_success( $data );
}

The patched version adds a current_user_can() check and uses sanitize_text_field() to prevent other potential issues.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with Happy Addons for Elementor version <= 3.20.3 installed and activated.
• Network access to the target site.

Exploitation Steps:

1. Identify Vulnerable Endpoint: Use a tool like Burp Suite or curl to probe for exposed AJAX actions. Common patterns include happy_* or happymonster_* actions.
2. Craft Request: Send a GET or POST request to /wp-admin/admin-ajax.php with the action parameter set to a vulnerable function (e.g., action=happy_get_widget_data).
3. Extract Data: If successful, the response will contain sensitive data in JSON format.

Example curl command:

curl -X GET "http://target-site.com/wp-admin/admin-ajax.php?action=happy_get_widget_data&widget_id=1"

Expected Response (if vulnerable):

{"success":true,"data":{"widget_name":"Example","settings":{"key":"value"}}}

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual requests to /wp-admin/admin-ajax.php with action parameters containing happy_ or happymonster_.
• Look for requests from unauthenticated users (no Cookie header with WordPress authentication cookies).
• Alert on responses containing plugin-specific data (e.g., happy_widget_ in the response body).

Defense:

• Immediate: Disable the Happy Addons for Elementor plugin until a patch is available.
• Workaround: Implement a Web Application Firewall (WAF) rule to block unauthenticated requests to known vulnerable endpoints.
• Long-term: Apply the principle of least privilege and ensure all AJAX actions include proper capability checks.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /wp-admin/admin-ajax.php with action=happy_* parameters from unauthenticated sources.
  • Responses containing JSON with keys like widget_name, settings, or happy_widget_.
• File IOCs:
  • Modified plugin files in /wp-content/plugins/happy-elementor-addons/ (if an attacker uploads a backdoor).
  • Unexpected files in the uploads directory (e.g., PHP shells).
• Log IOCs:
  • Repeated 200 OK responses to admin-ajax.php from the same IP without prior authentication.
  • Access logs showing POST /wp-admin/admin-ajax.php HTTP/1.1 with User-Agent not matching typical browsers.

Detection Engineering

YARA Rule

rule CVE_2025_63077_Happy_Addons_Missing_Auth {
    meta:
        description = "Detects exploitation attempts for CVE-2025-63077 in Happy Addons for Elementor"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-63077"
    strings:
        $ajax_action = "action=happy_" nocase
        $admin_ajax = "admin-ajax.php" nocase
        $response_data = "happy_widget_" nocase
    condition:
        $ajax_action and $admin_ajax and #response_data > 0
}

Sigma Rule

title: CVE-2025-63077 - Happy Addons Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated requests to Happy Addons AJAX endpoints
author: Valters IT
date: 2025/04/10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET' or 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=happy_'
        sc-status: 200
    condition: selection
falsepositives:
    - Legitimate admin actions (if admin is logged in, but this rule targets unauthenticated)
level: high

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-63077 - Happy Addons Missing Authorization Exploit";
    flow:to_server,established;
    content:"admin-ajax.php"; http_uri;
    content:"action=happy_"; http_uri;
    nocase;
    sid:10000001;
    rev:1;
    reference:cve,2025-63077;
    classtype:attempted-recon;
    priority:2;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the Plugin: Deactivate and remove the Happy Addons for Elementor plugin until a patched version is released.
2. Monitor Logs: Review web server and WordPress logs for signs of exploitation.
3. Apply WAF Rules: Block requests to /wp-admin/admin-ajax.php with action=happy_* from unauthenticated users.

Long-term Actions:

1. Patch: Apply the official patch as soon as it is released by HappyMonster.
2. Update: Keep all WordPress plugins and themes updated to the latest versions.
3. Audit: Regularly audit plugin code for missing authorization checks, especially in AJAX handlers.
4. Principle of Least Privilege: Ensure that all AJAX actions require appropriate capability checks (e.g., current_user_can()).

Workaround (if disabling is not possible):

• Use a plugin like "Code Snippets" to add a custom function that checks user capabilities before executing Happy Addons AJAX actions. Example:

add_action( 'init', function() {
    if ( defined( 'DOING_AJAX' ) && DOING_AJAX ) {
        $action = $_REQUEST['action'] ?? '';
        if ( strpos( $action, 'happy_' ) === 0 && ! is_user_logged_in() ) {
            wp_die( 'Unauthorized' );
        }
    }
});

Valters IT
Securing Digital Frontiers