CVE-2025-47471

Executive Summary

CVE-2025-47471 is a Missing Authorization vulnerability in the Envo Extra WordPress plugin (slug: envo-extra) developed by EnvoThemes. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized actions within the WordPress ecosystem. The vulnerability affects all versions from n/a through 1.9.9. 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 low probability of active exploitation in the wild, but the risk remains due to the lack of a patch.

Supply Chain & Package Security

This vulnerability is specific to the WordPress plugin ecosystem. The envo-extra plugin is distributed via the official WordPress plugin repository and is also bundled with EnvoThemes commercial themes. Organizations using EnvoThemes products should verify their plugin version and apply any available updates immediately. Since no patch is available, consider disabling the plugin or implementing virtual patching via a Web Application Firewall (WAF).

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N
• Base Score: 4.3 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: None (UI:N)
• Scope: Unchanged (S:U)
• Confidentiality Impact: None (C:N)
• Integrity Impact: Low (I:L)
• Availability Impact: None (A:N)

Threat Level: Medium. The vulnerability is easy to exploit remotely without authentication, but the impact is limited to low integrity compromise. Attackers could potentially modify non-critical settings or inject unauthorized content.

Deep Dive & Mechanics

The vulnerability resides in the Envo Extra plugin's AJAX handlers or REST API endpoints that fail to properly verify user capabilities before executing sensitive actions. In WordPress, plugins often register AJAX actions for both authenticated and unauthenticated users. A missing current_user_can() check or improper nonce validation can allow any visitor to trigger administrative functions.

Root Cause: The plugin does not enforce capability checks (e.g., manage_options, edit_posts) on certain callbacks, allowing unauthenticated users to invoke them. This is a classic CWE-862: Missing Authorization.

Attack Vector: An attacker sends a crafted HTTP request to the WordPress site targeting the vulnerable endpoint. Since no authentication is required, the request can be made from any browser or script.

Potential Impact:

• Unauthorized modification of plugin settings.
• Injection of malicious JavaScript or CSS.
• Bypass of security restrictions to perform actions like creating new users (if the endpoint allows it).
• Data exfiltration if the endpoint returns sensitive information.

Vulnerable vs. Patched Code

Since no patch is available, we can only analyze the vulnerable code pattern. A typical vulnerable snippet in WordPress plugins looks like:

// Vulnerable: No capability check
add_action('wp_ajax_nopriv_envo_extra_save_settings', 'envo_extra_save_settings');
function envo_extra_save_settings() {
    // Process and save settings without checking user permissions
    update_option('envo_extra_options', $_POST['options']);
}

Patched version (hypothetical):

// Patched: Added capability check
add_action('wp_ajax_nopriv_envo_extra_save_settings', 'envo_extra_save_settings');
function envo_extra_save_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    // Process and save settings
    update_option('envo_extra_options', $_POST['options']);
}

The fix requires adding current_user_can() checks for appropriate capabilities (e.g., manage_options for admin settings) and ensuring nonce verification is in place.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• Target WordPress site with Envo Extra plugin version <= 1.9.9.
• No authentication required.

Exploitation Steps:

1. Identify Vulnerable Endpoint: Use a tool like Burp Suite or curl to probe for AJAX actions. Common patterns include admin-ajax.php?action=envo_extra_*.

2. Craft Request: Send a POST request to the vulnerable endpoint with malicious payload.

curl -X POST https://target.com/wp-admin/admin-ajax.php \
  -d "action=envo_extra_save_settings&options[malicious]=value"

3. Verify Impact: Check if the settings were modified without authentication.

Note: Since no public PoC exists, the exact action name is unknown. Attackers would need to reverse-engineer the plugin code.

Blue Team (Defense & Detection)

Detection:

• Monitor for unusual POST requests to /wp-admin/admin-ajax.php with unknown or suspicious action parameters.
• Look for requests lacking a valid nonce or user session.
• Use WAF rules to block requests to AJAX endpoints that do not originate from authenticated users.

Mitigation:

• Disable the Envo Extra plugin until a patch is released.
• Implement virtual patching via WAF (e.g., ModSecurity rule to block envo_extra_* actions for unauthenticated users).
• Restrict access to admin-ajax.php using .htaccess or server-level rules.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin-ajax.php with action parameter containing envo_extra_.
  • Repeated requests from the same IP to AJAX endpoints without a valid session cookie.
• File IOCs:
  • Modified plugin options in the database (wp_options table with envo_extra_ prefix).
  • Unexpected files in /wp-content/uploads/ or plugin directories.
• Log IOCs:
  • Access logs showing POST /wp-admin/admin-ajax.php with HTTP 200 responses for unauthenticated users.
  • Error logs with wp_die or die messages related to authorization.

Detection Engineering

YARA Rule

rule CVE_2025_47471_Envo_Extra_Missing_Auth {
    meta:
        description = "Detects missing authorization in Envo Extra plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-47471"
    strings:
        $vuln_func = "wp_ajax_nopriv_envo_extra" nocase
        $missing_check = "current_user_can" nocase
    condition:
        $vuln_func and not $missing_check
}

Sigma Rule

title: CVE-2025-47471 - Missing Authorization in Envo Extra Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects exploitation attempts against missing authorization in Envo Extra plugin
author: Valters IT
date: 2025-04-10
references:
    - https://nvd.nist.gov/vuln/detail/CVE-2025-47471
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=envo_extra_'
    condition: selection
falsepositives:
    - Legitimate admin actions (requires authentication)
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-47471 - Envo Extra Missing Authorization Exploit";
    flow:to_server,established;
    content:"POST"; http_method;
    content:"admin-ajax.php"; http_uri;
    content:"action=envo_extra_"; http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
    reference:cve,2025-47471;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if it is not critical for business operations.
2. Apply virtual patching using WAF rules to block unauthenticated access to envo_extra_* AJAX actions.
3. Monitor logs for suspicious activity targeting admin-ajax.php.

Long-term Fix:

• The vendor (EnvoThemes) must release a patched version (>= 2.0.0) that includes proper capability checks and nonce verification.
• Until then, consider replacing the plugin with an alternative that provides similar functionality.

Workaround:

• Add the following code to the theme's functions.php to block unauthenticated access to the vulnerable endpoints:

add_action('init', function() {
    if (defined('DOING_AJAX') && DOING_AJAX && !is_user_logged_in()) {
        $allowed_actions = array('envo_extra_public_action'); // Whitelist safe actions
        $action = $_REQUEST['action'] ?? '';
        if (strpos($action, 'envo_extra_') === 0 && !in_array($action, $allowed_actions)) {
            wp_die('Unauthorized', 403);
        }
    }
});

Valters IT
Securing Digital Ecosystems