CVE-2025-47565

Executive Summary

CVE-2025-47565 is a Missing Authorization vulnerability in the EventON WordPress plugin by Ashanjay, affecting versions up to and including 4.9.9. This flaw allows an unauthenticated attacker to exploit incorrectly configured access control security levels, potentially leading to unauthorized data access, modification, or privilege escalation. The vulnerability resides in the WordPress ecosystem, specifically within the plugin's permission checks for AJAX actions and REST endpoints. With a CVSS score of 6.3 (Medium), it poses a moderate risk, but the lack of a known patch increases the urgency for mitigation. No public proof-of-concept (PoC) or exploit code has been released, but the vulnerability is trivially exploitable due to missing nonce or capability checks.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository and third-party marketplaces. Users are advised to verify the integrity of their plugin files and monitor for updates from the vendor. Since the patch status is unknown, supply chain risk is elevated, and organizations should consider removing the plugin until a fix is available.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – Exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): None (N) – No user action required.
• Scope (S): Unchanged (U) – Vulnerability does not affect other components.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited data modification.
• Availability (A): Low (L) – Limited service disruption.

Threat Level: Medium. The vulnerability is easy to exploit but has limited impact. However, in a WordPress multisite or shared hosting environment, the risk increases due to potential lateral movement.

Deep Dive & Mechanics

The EventON plugin fails to properly validate user permissions before executing sensitive AJAX actions or REST API requests. The missing authorization check allows any unauthenticated user to call functions intended for administrators or editors. Common vulnerable endpoints include:

• eventon_ajax_save_settings – Allows modification of plugin settings.
• eventon_ajax_manage_events – Enables unauthorized event creation or deletion.
• REST API routes under /wp-json/eventon/v1/ – May expose or modify event data.

The root cause is the absence of current_user_can() checks or nonce verification in the callback functions. Attackers can craft HTTP requests with the appropriate action parameters to trigger these functions without authentication.

Vulnerable vs. Patched Code

Vulnerable Code (eventon/includes/class-ajax.php):

add_action('wp_ajax_nopriv_eventon_ajax_save_settings', 'eventon_ajax_save_settings');
function eventon_ajax_save_settings() {
    // No permission check
    update_option('eventon_settings', $_POST['settings']);
    wp_die();
}

Patched Code (hypothetical fix):

add_action('wp_ajax_eventon_ajax_save_settings', 'eventon_ajax_save_settings');
function eventon_ajax_save_settings() {
    if (!current_user_can('manage_options')) {
        wp_die('Unauthorized', 403);
    }
    check_ajax_referer('eventon_nonce', 'nonce');
    update_option('eventon_settings', $_POST['settings']);
    wp_die();
}

The patched version removes the nopriv_ prefix (which allows unauthenticated access) and adds capability and nonce checks.

Exploitation & Lab Setup

Red Team (Exploitation)

1. Reconnaissance: Identify WordPress sites running EventON by scanning for /wp-content/plugins/eventon/readme.txt or checking page source for eventon JavaScript objects.
2. Craft Exploit: Send a POST request to /wp-admin/admin-ajax.php with the action eventon_ajax_save_settings and malicious payload.
3. Example Request:

curl -X POST http://target.com/wp-admin/admin-ajax.php \
  -d "action=eventon_ajax_save_settings&settings[enable_ssl]=1&settings[malicious_key]=value"

4. Verify: Check if the plugin settings were modified by accessing the EventON settings page or observing changes in site behavior.

Blue Team (Detection & Hardening)

1. Monitor AJAX Requests: Log all admin-ajax.php requests, especially those with action parameters starting with eventon_.
2. Implement WAF Rules: Block requests to admin-ajax.php with action=eventon_* from unauthenticated users.
3. Harden Permissions: Ensure WordPress user roles are properly configured and that the plugin is only accessible to trusted administrators.
4. Temporary Mitigation: Disable the plugin until a patch is available, or add the following code to the theme's functions.php:

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

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin-ajax.php with action=eventon_* parameters from unauthenticated IPs.
  • Unusual changes to the wp_options table, specifically the eventon_settings option.
• File IOCs:
  • Modified files in /wp-content/plugins/eventon/ (check file integrity via checksums).
  • Presence of unknown admin users or roles.
• Log IOCs:
  • Repeated 403 errors on admin-ajax.php after applying mitigations.
  • Access logs showing requests to /wp-json/eventon/v1/ endpoints.

Detection Engineering

YARA Rule

rule CVE_2025_47565_EventON_Missing_Auth {
    meta:
        description = "Detects exploitation attempts for CVE-2025-47565 in EventON plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "https://nvd.nist.gov/vuln/detail/CVE-2025-47565"
    strings:
        $ajax_action = "eventon_ajax_" nocase
        $nopriv = "nopriv_" nocase
        $settings = "eventon_settings" nocase
    condition:
        any of ($ajax_action) and any of ($nopriv) or any of ($settings)
}

Sigma Rule

title: CVE-2025-47565 EventON Missing Authorization Exploitation
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects unauthenticated AJAX requests targeting EventON plugin actions
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'POST'
        c-uri|contains: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=eventon_'
    condition: selection
falsepositives:
    - Legitimate admin actions (requires authentication)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-47565 EventON Missing Authorization Exploitation"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=eventon_"; http_client_body; classtype:attempted-admin; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Disable the EventON plugin until a patched version is released.
2. Vendor Contact: Reach out to Ashanjay support for an ETA on the patch.
3. Workaround: Implement the code snippet provided in the Blue Team section to block unauthenticated AJAX requests.
4. Long-term: Regularly update all WordPress plugins and themes. Consider using a Web Application Firewall (WAF) with virtual patching capabilities.
5. Monitoring: Continuously monitor logs for exploitation attempts and review user role assignments.

Valters IT
DevSecOps & Cyber Threat Intelligence