CVE-2025-1766: Eventin Auth Bypass Vulnerability

CVE-2025-1766 Overview

CVE-2025-1766 affects the Event Manager, Events Calendar, Tickets, Registrations – Eventin plugin for WordPress, developed by Themewinter. The plugin contains a missing capability check on the payment_complete function in all versions up to and including 4.0.24. Unauthenticated attackers can invoke this function over the network to mark ticket payment statuses as completed without providing valid payment. The flaw is categorized as [CWE-862] Missing Authorization and can lead to financial loss for site operators selling event tickets through the plugin.

Critical Impact
Unauthenticated attackers can mark ticket orders as paid in the Eventin plugin, bypassing payment collection and causing direct revenue loss for event organizers.

Affected Products

Themewinter Eventin plugin for WordPress, all versions up to and including 4.0.24
WordPress sites using the Event Manager, Events Calendar, Tickets, Registrations – Eventin plugin
Deployments exposing the plugin's payment controller endpoints to unauthenticated network traffic

Discovery Timeline

2025-03-20 - CVE-2025-1766 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-1766

Vulnerability Analysis

The vulnerability resides in the payment_complete function in core/Order/PaymentController.php of the Eventin plugin. The function updates ticket payment records to the completed state but omits a WordPress capability check and does not validate the requester's identity. As a result, any anonymous network client can send a request that transitions an order status without providing genuine payment authorization from a payment gateway.

The issue is a business logic and access control flaw rather than a memory or injection defect. It falls under [CWE-862] Missing Authorization, where a security-sensitive state transition is exposed without enforcing the required user role or nonce validation. The impact is limited to integrity of order data, which is why the CVSS integrity impact is rated Low with no confidentiality or availability effect.

Root Cause

The root cause is the absence of authorization enforcement in the payment_complete handler. WordPress plugins should call current_user_can(), verify a nonce with check_ajax_referer(), or validate a signed callback from the payment gateway before mutating order state. The vulnerable code path performs none of these checks, so the endpoint trusts any incoming request that supplies an order identifier.

Attack Vector

Exploitation requires only network access to the target WordPress site. An attacker identifies an existing order or ticket record and issues an HTTP request to the plugin's payment completion endpoint, supplying the order identifier. The plugin marks the order as paid, allowing the attacker to obtain event tickets or event access without completing a genuine transaction through the configured payment processor.

No exploit code is publicly available and the CVE is not listed on the CISA Known Exploited Vulnerabilities catalog. The EPSS probability is 0.343% at percentile 26.42, indicating limited observed exploitation activity to date. Technical detail on the affected function is available in the WordPress Plugin Code Reference and the Wordfence Vulnerability Analysis.

Detection Methods for CVE-2025-1766

Indicators of Compromise

Ticket orders transitioning to completed status without a corresponding payment gateway transaction ID or webhook record
Unauthenticated HTTP POST requests to the Eventin plugin's payment completion endpoint under /wp-json/ or admin-ajax.php routes
Ticket issuance to email addresses or user accounts not associated with any processed payment
Sudden spikes in completed orders originating from a small set of source IP addresses

Detection Strategies

Review the WordPress wp_posts and Eventin order tables for orders marked completed with null or missing transaction references from Stripe, PayPal, or other configured gateways
Correlate web server access logs with payment gateway logs to identify orders completed without a matching gateway callback
Deploy a Web Application Firewall (WAF) rule that logs or blocks requests to the payment_complete endpoint from unauthenticated sessions

Monitoring Recommendations

Alert on the ratio of completed orders to gateway-confirmed payments deviating from historical baselines
Monitor plugin file integrity for core/Order/PaymentController.php and confirm the deployed version is 4.0.25 or later
Track the version string of the Eventin plugin across all managed WordPress sites and flag any instance still reporting a version at or below 4.0.24

How to Mitigate CVE-2025-1766

Immediate Actions Required

Update the Eventin plugin to a version later than 4.0.24 on every affected WordPress site
Reconcile all orders marked completed since the plugin was installed against payment gateway records and void or refund fraudulent tickets
Restrict access to the plugin's REST and AJAX endpoints at the WAF or reverse proxy layer until patching is confirmed

Patch Information

Themewinter addressed the missing authorization check in a plugin update following version 4.0.24. The corresponding code change is documented in the WordPress Plugin Changeset Details. Site administrators should apply the update through the WordPress admin dashboard or by pulling the latest release from the plugin repository, then verify that the installed version reflects the patched release.

Workarounds

Disable the Eventin plugin until the patched version can be installed if immediate updating is not possible
Block unauthenticated access to the payment_complete route at a WAF, reverse proxy, or .htaccess layer
Temporarily disable ticket sales in the Eventin settings to prevent order records from being manipulated while a patch is pending

bash

# Configuration example
# Update the Eventin plugin via WP-CLI
wp plugin update wp-event-solution

# Verify the installed version is above 4.0.24
wp plugin get wp-event-solution --field=version