CVE-2025-39376: Car Park Booking System Auth Bypass Flaw

CVE-2025-39376 Overview

CVE-2025-39376 is a missing authorization vulnerability in the QuanticaLabs Car Park Booking System for WordPress plugin. The flaw affects all plugin versions up to and including 2.6. An authenticated attacker with low privileges can invoke plugin actions that should be restricted to higher-privileged roles. The issue is classified under CWE-862: Missing Authorization and stems from broken access control checks within plugin request handlers.

Critical Impact
Authenticated low-privilege users can perform actions restricted to higher roles, resulting in unauthorized modification of booking data within the WordPress site.

Affected Products

QuanticaLabs Car Park Booking System for WordPress plugin
All versions from n/a through 2.6
WordPress sites running the car-park-booking-system-for-wordpress plugin

Discovery Timeline

2025-05-19 - CVE-2025-39376 published to the National Vulnerability Database
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-39376

Vulnerability Analysis

The Car Park Booking System for WordPress plugin exposes handlers that do not verify the acting user's capability before executing sensitive operations. The plugin trusts the presence of a valid session but omits role and capability checks. As a result, any authenticated account, including a Subscriber, can trigger functions intended for administrative use. The attack does not require user interaction and is delivered over the network against the WordPress endpoint.

The impact is limited to integrity. Confidentiality and availability are not affected according to the CVSS vector. Attackers can modify booking-related data without authorization, which can disrupt reservation records and business logic tied to parking availability.

Root Cause

The root cause is missing authorization enforcement [CWE-862] in one or more plugin request handlers. WordPress plugins are expected to call current_user_can() alongside nonce verification before performing state-changing operations. This plugin omits the capability check, so the server accepts requests from any authenticated user regardless of their assigned role.

Attack Vector

Exploitation requires an authenticated account on the target WordPress site. The attacker sends a crafted HTTP request to the vulnerable plugin action, either through the AJAX endpoint or an admin-post handler. Because the handler does not enforce role restrictions, the request executes with the attacker's session but without the capability constraints that would normally block it. Refer to the Patchstack Vulnerability Report for the technical write-up.

Detection Methods for CVE-2025-39376

Indicators of Compromise

Unexpected changes to car park booking records, pricing, or availability configuration in the WordPress database.
HTTP POST requests to plugin AJAX or admin-post endpoints originating from low-privileged accounts such as Subscribers.
WordPress audit log entries showing state-changing plugin actions performed by non-administrative users.

Detection Strategies

Review web server access logs for POST requests to admin-ajax.php or admin-post.php referencing plugin action names tied to car-park-booking-system-for-wordpress.
Correlate the authenticated user cookie or session with the requested action, and flag mismatches between the user role and the action's expected privilege level.
Enable a WordPress activity log plugin to record capability-sensitive operations and alert on modifications performed by Subscriber or Contributor accounts.

Monitoring Recommendations

Monitor for account creation spikes, since Missing Authorization flaws are frequently chained with open registration to gain a low-privileged foothold.
Alert on outbound requests or configuration changes originating shortly after new account registration on WordPress sites hosting the affected plugin.
Track plugin version inventory across managed WordPress sites and flag any instance still running version 2.6 or earlier.

How to Mitigate CVE-2025-39376

Immediate Actions Required

Identify all WordPress installations running the Car Park Booking System for WordPress plugin at version 2.6 or earlier.
Disable the plugin until a patched release is installed if a fixed version is not yet applied.
Audit existing WordPress user accounts and remove or downgrade any unverified low-privileged accounts.

Patch Information

At the time of publication, the vendor advisory indexed by Patchstack lists the vulnerability as affecting versions through 2.6. Administrators should consult the Patchstack Vulnerability Report and the QuanticaLabs product page for the latest fixed release, then update through the WordPress plugin manager.

Workarounds

Restrict access to wp-admin/admin-ajax.php for unauthenticated and low-privileged users using a Web Application Firewall rule that inspects the action parameter.
Disable public user registration under Settings → General if it is not required by the site.
Apply a virtual patch through a WordPress security plugin that enforces capability checks on the vulnerable action.

bash

# Example WAF rule sketch (ModSecurity) to block low-privileged access to plugin actions
SecRule REQUEST_URI "@contains /wp-admin/admin-ajax.php" \
  "chain,phase:2,deny,status:403,id:1039376,msg:'Block CVE-2025-39376 plugin action'"
  SecRule ARGS:action "@rx ^(carpark_|cpbs_)" "t:none"