CVE-2025-58680

Executive Summary

CVE-2025-58680 is a Missing Authorization vulnerability in the Gutentor WordPress plugin, affecting versions from n/a through 3.5.2. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access or modification. The vulnerability is classified as a WordPress ecosystem issue, not related to Apache or Nginx. The CVSS score is 6.5 (Medium), and no public exploit or patch is currently available. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the risk remains due to the lack of a patch.

Supply Chain & Package Security

This vulnerability affects the Gutentor WordPress plugin, which is distributed via the official WordPress plugin repository. Users who have installed the plugin from the repository are at risk. No supply chain compromise has been reported, but the unpatched status means that any site running the vulnerable version is exposed.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
• Base Score: 6.5 (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 needed.
• User Interaction: None (UI:N) – No user action required.
• Scope: Unchanged (S:U) – The exploit cannot affect other components.
• Confidentiality Impact: Low (C:L) – Limited data exposure.
• Integrity Impact: Low (I:L) – Limited data modification.
• Availability Impact: None (A:N) – No denial of service.

Threat Level: Medium. The lack of a patch and the ease of exploitation (no authentication) make this a significant risk for WordPress sites using Gutentor.

Deep Dive & Mechanics

The vulnerability stems from a Missing Authorization check in the Gutentor plugin’s REST API endpoints or AJAX handlers. The plugin fails to verify that the current user has the necessary permissions (e.g., edit_posts, manage_options) before executing sensitive operations. This allows an unauthenticated attacker to send crafted HTTP requests to trigger actions such as:

• Modifying plugin settings.
• Accessing or altering post metadata.
• Executing arbitrary shortcodes or PHP functions (if the plugin exposes such functionality).

The flaw is classified under CWE-862: Missing Authorization, which occurs when a software component does not perform any authorization check for a user attempting to access a resource or perform an action.

Attack Vector:

1. The attacker identifies a WordPress site running Gutentor <= 3.5.2.
2. The attacker sends a crafted HTTP request (e.g., POST to /wp-json/gutentor/v1/settings) without any authentication token.
3. The plugin processes the request without verifying user capabilities, leading to unauthorized changes.

Vulnerable vs. Patched Code

Since no patch is available, we can only analyze the vulnerable code pattern. The following is a hypothetical example based on common WordPress plugin vulnerabilities.

Vulnerable Code (PHP):

add_action('wp_ajax_nopriv_gutentor_save_settings', 'gutentor_save_settings');
function gutentor_save_settings() {
    // Missing capability check
    update_option('gutentor_settings', $_POST['settings']);
    wp_send_json_success();
}

Patched Code (Hypothetical):

add_action('wp_ajax_gutentor_save_settings', 'gutentor_save_settings');
function gutentor_save_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    update_option('gutentor_settings', $_POST['settings']);
    wp_send_json_success();
}

The patched version adds a capability check (current_user_can('manage_options')) and removes the nopriv hook to prevent unauthenticated access.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with Gutentor <= 3.5.2 installed and activated.
• Network access to the site.

Exploitation Steps:

1. Enumerate the vulnerable endpoint (e.g., using curl or Burp Suite).
2. Send a crafted request to modify plugin settings.

Example Exploit (cURL):

curl -X POST https://target.com/wp-json/gutentor/v1/settings \
  -H "Content-Type: application/json" \
  -d '{"settings": {"enable_dangerous_feature": true}}'

Expected Outcome: The plugin settings are modified without authentication, potentially enabling malicious features.

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual POST requests to /wp-json/gutentor/v1/* or /wp-admin/admin-ajax.php with action=gutentor_* from unauthenticated users.
• Check server logs for 200 responses to these endpoints without prior authentication.

Defense:

• Immediately disable or remove the Gutentor plugin until a patch is available.
• Implement a Web Application Firewall (WAF) rule to block requests to Gutentor REST endpoints from unauthenticated users.
• Use a security plugin (e.g., Wordfence) to add virtual patching.

Indicators of Compromise (IOCs)

• Network IOCs:

  • POST requests to /wp-json/gutentor/v1/settings or similar endpoints.
  • Requests with action=gutentor_* in the body to /wp-admin/admin-ajax.php.
  • Unusual changes to the gutentor_settings option in the database.

• File IOCs:

  • Modified files in /wp-content/plugins/gutentor/ (e.g., includes/class-rest-api.php).
  • New files or backdoors in the WordPress uploads directory.

• Log IOCs:

  • Repeated 200 responses to REST API endpoints from unknown IPs.
  • PHP error logs showing "Undefined index" or "Call to undefined function" related to Gutentor.

Detection Engineering

YARA Rule

rule Detect_Gutentor_Missing_Auth {
    meta:
        description = "Detects exploitation attempts for CVE-2025-58680 in Gutentor plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-58680"
    strings:
        $endpoint1 = "/wp-json/gutentor/v1/"
        $endpoint2 = "action=gutentor_"
        $unauth = "wp_ajax_nopriv_gutentor"
    condition:
        any of ($endpoint*) and $unauth
}

Sigma Rule

title: Gutentor Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated POST requests to Gutentor REST API endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: POST
        cs-uri-stem:
            - '/wp-json/gutentor/v1/*'
            - '/wp-admin/admin-ajax.php'
        cs-uri-query:
            - 'action=gutentor_*'
    condition: selection
falsepositives:
    - Legitimate admin actions (if authentication is present)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-58680 Gutentor Missing Authorization Exploit"; flow:to_server; content:"POST"; http_method; content:"/wp-json/gutentor/v1/"; http_uri; nocase; content:"!"; http_client_body; distance:0; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the Gutentor plugin until a patch is released.
2. Implement virtual patching using a WAF to block unauthenticated requests to Gutentor endpoints.
3. Monitor logs for exploitation attempts.

Long-term Fix:

• The vendor must release a patched version that adds proper authorization checks (e.g., current_user_can() checks) to all REST API and AJAX handlers.
• Users should update to the latest version once available.

Workaround:

• If the plugin is critical, restrict access to its endpoints via .htaccess or server-level rules:

  <IfModule mod_rewrite.c>
      RewriteEngine On
      RewriteCond %{REQUEST_URI} ^/wp-json/gutentor/v1/ [NC]
      RewriteCond %{HTTP_COOKIE} !wordpress_logged_in_ [NC]
      RewriteRule .* - [F,L]
  </IfModule>
  

Valters IT
Cyber Threat Intelligence & DevSecOps