CVE-2025-62027

Executive Summary

CVE-2025-62027 is a Missing Authorization vulnerability (CWE-862) in the StellarWP Event Tickets WordPress plugin, affecting versions from n/a through 5.26.3. This flaw allows unauthenticated attackers to bypass authorization checks, potentially leading to unauthorized access to ticket data or administrative actions. The vulnerability has a CVSS score of 5.4 (Medium), with an EPSS score of 0.0%, indicating low exploitation likelihood at this time. No public proof-of-concept (PoC) or patch is currently available.

As this is a WordPress plugin vulnerability, it is critical to treat it within the WordPress ecosystem context. The issue lies in the plugin's failure to properly verify user permissions before executing sensitive operations, such as viewing or modifying ticket metadata.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users should verify the integrity of their plugin files and monitor for updates from StellarWP. No known supply chain compromise has been reported.

CVSS Breakdown & Threat Level

• CVSS Score: 5.4 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: None
• Scope: Unchanged
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

The threat level is Medium due to the low complexity and no required privileges, but the impact is limited to low confidentiality and integrity loss.

Deep Dive & Mechanics

The vulnerability resides in the authorization logic of the Event Tickets plugin. The plugin fails to enforce proper capability checks on certain AJAX actions or REST API endpoints, allowing unauthenticated users to access or modify ticket data. Specifically, the plugin does not validate the current_user_can() function for actions like retrieving ticket details, updating ticket quantities, or managing event attendees.

The missing authorization check can be exploited by sending crafted HTTP requests to the vulnerable endpoints. For example, an attacker could enumerate ticket IDs, view attendee information, or modify ticket stock levels without authentication.

Vulnerable vs. Patched Code

Vulnerable Code (<= 5.26.3):

add_action('wp_ajax_nopriv_get_ticket', 'handle_get_ticket');
function handle_get_ticket() {
    $ticket_id = $_POST['ticket_id'];
    // Missing capability check
    $ticket = get_post($ticket_id);
    wp_send_json($ticket);
}

Patched Code (Hypothetical):

add_action('wp_ajax_nopriv_get_ticket', 'handle_get_ticket');
function handle_get_ticket() {
    if (!current_user_can('read_ticket')) {
        wp_die('Unauthorized', 403);
    }
    $ticket_id = $_POST['ticket_id'];
    $ticket = get_post($ticket_id);
    wp_send_json($ticket);
}

The patched version adds a capability check using current_user_can() before processing the request.

Exploitation & Lab Setup

Red Team

1. Setup: Install WordPress with Event Tickets plugin version 5.26.3 on a local server.
2. Reconnaissance: Identify vulnerable endpoints by analyzing plugin source code or using fuzzing tools.
3. Exploitation: Send a crafted POST request to the vulnerable endpoint:

   curl -X POST http://target/wp-admin/admin-ajax.php \
        -d 'action=get_ticket&ticket_id=123' \
        -H 'Content-Type: application/x-www-form-urlencoded'
   

4. Post-Exploitation: Extract ticket data, modify stock, or access attendee information.

Blue Team

1. Detection: Monitor for unusual AJAX requests to admin-ajax.php with actions like get_ticket, update_ticket, or delete_ticket from unauthenticated users.
2. Mitigation: Implement a Web Application Firewall (WAF) rule to block requests to these endpoints without authentication.
3. Hunting: Search logs for requests containing action=get_ticket and ticket_id parameters from IPs not associated with authenticated users.

Indicators of Compromise (IOCs)

• Network IOCs:
  • POST requests to /wp-admin/admin-ajax.php with action=get_ticket or similar.
  • Unusual ticket_id parameter values (e.g., sequential IDs).
• File IOCs:
  • Modified plugin files in /wp-content/plugins/event-tickets/.
• Log IOCs:
  • Repeated 403 errors from admin-ajax.php after applying a WAF rule.
  • Access logs showing unauthenticated requests to AJAX endpoints.

Detection Engineering

YARA Rule

rule CVE_2025_62027_Event_Tickets {
    meta:
        description = "Detects missing authorization in Event Tickets plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2025-62027"
    strings:
        $vuln_func = "wp_ajax_nopriv_" ascii wide
        $cap_check = "current_user_can" ascii wide
    condition:
        $vuln_func and not $cap_check
}

Sigma Rule

title: CVE-2025-62027 - Missing Authorization in Event Tickets
id: 12345678-1234-1234-1234-123456789012
status: experimental
description: Detects unauthenticated AJAX requests to vulnerable Event Tickets endpoints
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-stem: '/wp-admin/admin-ajax.php'
        cs-uri-query|contains: 'action=get_ticket'
    condition: selection
falsepositives:
    - Legitimate plugin functionality (rare)
level: medium

Suricata Rule

alert http any any -> any any (msg:"CVE-2025-62027 - Event Tickets Missing Authorization"; flow:to_server; content:"POST"; http_method; content:"/wp-admin/admin-ajax.php"; http_uri; content:"action=get_ticket"; http_client_body; classtype:attempted-recon; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:
   • Disable the Event Tickets plugin until a patch is available.
   • Implement a WAF rule to block unauthenticated requests to admin-ajax.php with suspicious actions.
2. Long-term Fix:
   • Apply the vendor patch when released (monitor StellarWP updates).
   • Review and harden all AJAX endpoints in the plugin.
3. Workarounds:
   • Use a security plugin like Wordfence to add virtual patching.
   • Restrict access to admin-ajax.php via .htaccess for non-logged-in users.

Valters IT
Securing Digital Frontiers