CVE-2025-69016

Executive Summary

CVE-2025-69016 is a Missing Authorization vulnerability in the Averta Shortcodes and extra features for Phlox theme plugin (auxin-elements). This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized access to certain plugin functionalities. The vulnerability affects all versions up to and including 2.17.15. As of this report, no official patch has been released, and no public proof-of-concept (PoC) or exploit code is available. The CVSS score is 4.3 (Medium), indicating a moderate risk primarily due to low attack complexity and no required privileges, but with limited impact on confidentiality.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin (auxin-elements), which is distributed through the official WordPress plugin repository and third-party marketplaces. The plugin is a dependency for the Phlox theme, meaning any site using the Phlox theme with the auxin-elements plugin installed is potentially affected. Since no patch is available, site administrators must rely on manual mitigation steps, such as disabling the plugin or implementing custom access controls via a Web Application Firewall (WAF). The lack of a patch increases supply chain risk, as attackers may target unpatched installations.

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 (AV): Network – The vulnerability can be exploited remotely.
• Attack Complexity (AC): Low – No special conditions or complex steps are required.
• Privileges Required (PR): None – No authentication is needed.
• User Interaction (UI): None – The attacker does not need to trick a user.
• Scope (S): Unchanged – The exploit cannot affect other components.
• Confidentiality (C): Low – Limited information disclosure is possible.
• Integrity (I): None – No data modification is possible.
• Availability (A): None – No denial-of-service impact.

Threat Level: Medium. The vulnerability is easy to exploit but only allows limited information disclosure. However, in a WordPress ecosystem, even low-severity authorization flaws can be chained with other vulnerabilities to escalate privileges or access sensitive data.

Deep Dive & Mechanics

The vulnerability stems from Missing Authorization (CWE-862) in the auxin-elements plugin. The plugin provides shortcodes and extra features for the Phlox theme, including custom post types, widgets, and AJAX endpoints. The flaw likely exists in one or more AJAX actions or REST API endpoints that fail to properly verify user capabilities before processing requests.

Root Cause: The plugin does not implement capability checks (e.g., current_user_can()) for certain administrative functions. This allows unauthenticated attackers to call these functions directly via crafted HTTP requests.

Attack Vector: An attacker can send a specially crafted HTTP request to a vulnerable endpoint (e.g., /wp-admin/admin-ajax.php with a specific action parameter) to trigger the missing authorization. The exact endpoint is not publicly documented, but common patterns in similar plugins include actions like auxin_save_settings, auxin_get_data, or auxin_import.

Impact: Successful exploitation could allow an attacker to:

• Read sensitive plugin configuration data.
• Access internal plugin states or cached data.
• Potentially trigger other plugin functions that should be restricted to administrators.

Vulnerable vs. Patched Code

Since no patch is available, a direct code comparison is not possible. However, based on the CWE description, the vulnerable code likely resembles:

Vulnerable Code (PHP):

add_action('wp_ajax_auxin_save_settings', 'auxin_save_settings_callback');
add_action('wp_ajax_nopriv_auxin_save_settings', 'auxin_save_settings_callback');

function auxin_save_settings_callback() {
    // Missing capability check
    $settings = $_POST['settings'];
    update_option('auxin_settings', $settings);
    wp_die();
}

Patched Code (Expected):

add_action('wp_ajax_auxin_save_settings', 'auxin_save_settings_callback');
// Remove the nopriv action to prevent unauthenticated access

function auxin_save_settings_callback() {
    // Add capability check
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    $settings = $_POST['settings'];
    update_option('auxin_settings', $settings);
    wp_die();
}

The patch would involve adding current_user_can() checks to all AJAX and REST endpoints that handle sensitive operations.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site running Phlox theme with auxin-elements plugin version <= 2.17.15.
• Network access to the target.

Exploitation Steps:

1. Identify Vulnerable Endpoint: Use a tool like Burp Suite or curl to probe common AJAX actions. Example:

   curl -X POST http://target/wp-admin/admin-ajax.php \
        -d "action=auxin_get_settings"
   

2. Craft Exploit: If the endpoint returns data without authentication, the vulnerability is confirmed. For example:

   curl -X POST http://target/wp-admin/admin-ajax.php \
        -d "action=auxin_export_data"
   

3. Extract Data: The response may contain plugin configuration, user data, or other sensitive information.

Note: No public exploit code is available, so this is a generic approach.

Blue Team (Detection & Defense)

Detection:

• Monitor for unusual AJAX requests to admin-ajax.php with actions related to auxin (e.g., auxin_*).
• Look for requests from unauthenticated users (no wp_* cookies) to administrative AJAX endpoints.

Defense:

• Immediate: Disable the auxin-elements plugin if not essential.
• WAF Rule: Block requests to admin-ajax.php with action parameters starting with auxin_ from unauthenticated users.
• Monitor Logs: Check WordPress debug logs for unauthorized access attempts.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP POST requests to /wp-admin/admin-ajax.php with action=auxin_* parameters from unknown IPs.
  • Unusual response sizes from AJAX endpoints (e.g., returning plugin configuration data).
• File IOCs:
  • Modified wp-content/plugins/auxin-elements/ files (if attacker uploads malicious code).
• Log IOCs:
  • WordPress debug.log entries showing PHP Notice: Undefined index: or PHP Warning: Cannot modify header information related to AJAX calls.

Detection Engineering

YARA Rule

rule CVE_2025_69016_Auxin_Elements {
    meta:
        description = "Detects vulnerable auxin-elements plugin files"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-69016"
    strings:
        $vuln_func = "wp_ajax_nopriv_auxin" nocase
        $vuln_action = "auxin_" nocase
    condition:
        $vuln_func or $vuln_action
}

Sigma Rule

title: CVE-2025-69016 - Missing Authorization in auxin-elements
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects unauthenticated AJAX requests to auxin-elements endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'admin-ajax.php'
        cs-uri-query|contains: 'action=auxin_'
    condition: selection
falsepositives:
    - Legitimate admin actions (if authenticated)
level: medium

Suricata Rule

alert http any any -> $HOME_NET any (
    msg:"CVE-2025-69016 - Unauthenticated auxin-elements AJAX request";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"admin-ajax.php";
    http_uri;
    content:"action=auxin_";
    http_client_body;
    classtype:attempted-recon;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the Plugin: Deactivate and delete the auxin-elements plugin until a patch is released.
2. Web Application Firewall (WAF): Create custom rules to block unauthenticated requests to admin-ajax.php with action parameters starting with auxin_.
3. Monitor Logs: Enable WordPress debug logging and review for suspicious AJAX activity.

Long-Term Fix:

• Await an official patch from Averta. Monitor the WordPress plugin repository for updates.
• Once patched, update to the latest version immediately.

Workaround:

• If the plugin is critical, implement a custom capability check via a WordPress mu-plugin:

  add_action('init', function() {
      if (defined('DOING_AJAX') && DOING_AJAX) {
          $action = $_REQUEST['action'] ?? '';
          if (strpos($action, 'auxin_') === 0 && !current_user_can('manage_options')) {
              wp_die('Unauthorized', 403);
          }
      }
  });
  

Valters IT
Securing Digital Ecosystems