CVE-2025-64255

Executive Summary

CVE-2025-64255 is a Missing Authorization vulnerability in the Admin and Site Enhancements (ASE) WordPress plugin, affecting versions up to and including 8.0.8. This flaw allows an authenticated attacker with high privileges (e.g., Administrator) to exploit incorrectly configured access control security levels, potentially leading to unauthorized actions within the WordPress admin panel. The vulnerability is classified as low severity (CVSS 2.7) due to the high privileges required and limited impact on integrity. No public proof-of-concept (PoC) or exploit code has been released, and the vendor has not provided a patch.

Supply Chain & Package Security

This vulnerability resides in a WordPress plugin distributed via the official WordPress plugin repository. As a supply chain risk, any site running ASE <= 8.0.8 is exposed. Since the plugin is widely used for admin enhancements, the attack surface includes all installations where the plugin is active. No known malicious packages have been identified, but the lack of a patch increases the risk of future exploitation.

CVSS Breakdown & Threat Level

• CVSS Score: 2.7 (Low)
• Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: High (Administrator)
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: None
• Integrity Impact: Low
• Availability Impact: None

Threat Level: Low. Exploitation requires high privileges, limiting the attack to already trusted users. However, in multi-tenant or shared admin environments, this could be leveraged for privilege escalation or unauthorized modifications.

Deep Dive & Mechanics

The vulnerability stems from Missing Authorization (CWE-862) in the ASE plugin's admin functionality. The plugin fails to properly verify that the current user has the necessary capabilities before executing certain actions. Specifically, the admin-site-enhancements component does not enforce capability checks on AJAX handlers or admin pages, allowing a user with high privileges (e.g., Administrator) to perform actions that should be restricted to super admins or specific roles.

Root Cause: The plugin uses current_user_can() inconsistently or not at all for certain endpoints. For example, an AJAX action like ase_save_settings might only check for manage_options capability, which is available to Administrators, but fails to verify if the user is allowed to modify specific settings that affect other users or site-wide configurations.

Attack Scenario: An authenticated Administrator can craft a malicious request to modify plugin settings, such as disabling security features, altering user roles, or injecting malicious JavaScript into admin pages. This could lead to persistent cross-site scripting (XSS) or privilege escalation for lower-privileged users.

Vulnerable vs. Patched Code

Since no patch is available, we analyze the vulnerable code pattern. The vulnerable version likely contains code similar to:

// Vulnerable: No capability check
add_action('wp_ajax_ase_save_settings', 'ase_save_settings_callback');
function ase_save_settings_callback() {
    // Process and save settings without checking user capabilities
    update_option('ase_settings', $_POST['settings']);
    wp_die();
}

A patched version would include:

// Patched: Capability check added
add_action('wp_ajax_ase_save_settings', 'ase_save_settings_callback');
function ase_save_settings_callback() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
    // Process and save settings
    update_option('ase_settings', $_POST['settings']);
    wp_die();
}

The fix ensures that only users with the manage_options capability can execute the action. However, for more granular control, checks for install_plugins or activate_plugins may be needed.

Exploitation & Lab Setup

Red Team

Prerequisites:

• WordPress installation with ASE plugin <= 8.0.8
• Valid Administrator credentials

Exploitation Steps:

1. Identify Vulnerable Endpoint: Use browser developer tools to find AJAX actions. For example, admin-ajax.php?action=ase_save_settings.

2. Craft Malicious Request: Send a POST request with modified settings.

curl -X POST http://target/wp-admin/admin-ajax.php \
  -d "action=ase_save_settings&settings[disable_security]=1" \
  --cookie "wordpress_logged_in_xxx=admin_cookie"

3. Verify Impact: Check if security features are disabled or settings changed.

Note: No public exploit code exists; this is a theoretical demonstration.

Blue Team

Detection:

• Monitor for unusual AJAX requests to admin-ajax.php with actions related to ASE (e.g., ase_save_settings, ase_update_option).
• Look for rapid changes in plugin settings via audit logs.

Hunting:

• Search for ase_ prefixed actions in web server logs.
• Use the Sigma rule below to detect unauthorized access attempts.

Indicators of Compromise (IOCs)

• File Paths:
  • /wp-content/plugins/admin-site-enhancements/
  • /wp-content/plugins/admin-site-enhancements/includes/class-ajax.php
• URL Patterns:
  • /wp-admin/admin-ajax.php?action=ase_*
• Log Entries:
  • POST requests to admin-ajax.php with action=ase_save_settings from non-admin IPs (if privilege escalation occurs).
• Database Changes:
  • Modified wp_options table entries with ase_ prefix.

Detection Engineering

YARA Rule

rule CVE_2025_64255_ASE_Missing_Auth {
    meta:
        description = "Detects missing authorization in Admin and Site Enhancements plugin"
        author = "Valters IT"
        date = "2025-04-10"
        cve = "CVE-2025-64255"
    strings:
        $vuln_func = "add_action('wp_ajax_ase_" ascii wide nocase
        $no_cap = "current_user_can" ascii wide nocase
    condition:
        $vuln_func and not $no_cap
}

Sigma Rule

title: CVE-2025-64255 - Missing Authorization in ASE Plugin
id: 8a4b3c2d-1e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects attempts to exploit missing authorization in Admin and Site Enhancements plugin
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'action=ase_'
    condition: selection
falsepositives:
    - Legitimate admin actions
level: medium

Suricata Rule

alert http any any -> any any (
    msg:"CVE-2025-64255 - Missing Authorization in ASE Plugin";
    flow:to_server,established;
    content:"POST";
    http_method;
    content:"admin-ajax.php";
    http_uri;
    content:"action=ase_";
    http_client_body;
    classtype:attempted-admin;
    sid:1000001;
    rev:1;
)

Remediation & Mitigation

Immediate Actions:

1. Disable the Plugin: If ASE is not critical, deactivate and delete it until a patch is released.
2. Restrict Admin Access: Limit the number of users with Administrator privileges. Use role-based access control.
3. Web Application Firewall (WAF): Block requests to admin-ajax.php with action=ase_* from non-admin IPs.

Long-term Fix:

• Monitor the plugin's official page for updates. Apply the patch as soon as it becomes available.
• Implement custom capability checks in the plugin code if you have development resources.

Workaround:

• Add a custom function to your theme's functions.php to enforce capability checks:

add_action('wp_ajax_ase_save_settings', function() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized');
    }
}, 1);

Valters IT
Securing Digital Frontiers