CVE-2025-31882: WebinarPress Authorization Bypass Vulnerability

CVE-2025-31882 Overview

CVE-2025-31882 is a missing authorization vulnerability in the WPWebinarSystem WebinarPress plugin for WordPress. The flaw affects the wp-webinarsystem plugin in all versions up to and including 1.33.28. Attackers with low-privilege authenticated access can exploit incorrectly configured access control checks to reach functionality that should be restricted. The vulnerability is categorized as Broken Access Control under [CWE-862: Missing Authorization]. It stems from the plugin failing to validate user capabilities before executing sensitive operations, exposing confidentiality of data managed by the plugin.

Critical Impact
Authenticated attackers with minimal privileges can access plugin functionality intended for higher-privileged roles, leading to unauthorized disclosure of webinar-related data.

Affected Products

WPWebinarSystem WebinarPress plugin for WordPress
WebinarPress wp-webinarsystem versions from n/a through 1.33.28
WebinarPress Lite edition for WordPress

Discovery Timeline

2025-04-01 - CVE-2025-31882 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-31882

Vulnerability Analysis

The vulnerability is a Missing Authorization flaw ([CWE-862]) in the WebinarPress WordPress plugin. The plugin exposes actions that do not verify whether the calling user holds the required capability. An authenticated user with a low-privilege role can invoke these actions directly and receive data that should be restricted to administrators or webinar operators. The issue is scoped to confidentiality: exploitation does not, by itself, modify data or affect availability. Because the vector is network-based and requires only low privileges with no user interaction, exploitation is straightforward on any WordPress site that permits user registration or provides subscriber-level accounts.

Root Cause

The root cause is the absence of current_user_can() capability checks (or equivalent nonce and role validation) on plugin request handlers. WordPress plugins must gate privileged actions behind explicit authorization checks. WebinarPress registers handlers reachable by authenticated users but does not enforce role or capability constraints before executing the underlying logic.

Attack Vector

An attacker authenticates to the target WordPress site using any low-privilege account, including a Subscriber role. The attacker then issues HTTP requests to the vulnerable plugin endpoints, typically through admin-ajax.php or a plugin-registered REST route. Because the handler skips the authorization check, the server returns data or performs an action the attacker should not have access to. No social engineering or user interaction is required.

No verified public proof-of-concept code is available. Refer to the Patchstack advisory for WebinarPress for technical details.

Detection Methods for CVE-2025-31882

Indicators of Compromise

Unexpected requests from Subscriber-level accounts to admin-ajax.php containing WebinarPress action parameters such as action=webinarpress_* or action=wp_webinarsystem_*.
HTTP 200 responses to plugin endpoints from user sessions that lack Editor or Administrator roles.
Access log entries showing repeated enumeration of WebinarPress REST routes under /wp-json/ from a single authenticated session.

Detection Strategies

Review WordPress access logs for authenticated requests to WebinarPress endpoints originating from low-privilege user IDs.
Deploy a Web Application Firewall rule that inspects action parameters targeting wp-webinarsystem and correlates them with the requester's role cookie.
Enable a WordPress audit-logging plugin to capture the user, capability, and endpoint of each plugin action.

Monitoring Recommendations

Alert on newly created Subscriber accounts that issue plugin AJAX or REST requests within the first session.
Monitor for spikes in admin-ajax.php traffic tied to the WebinarPress plugin namespace.
Track outbound data volume from WordPress hosts to identify enumeration or bulk data pulls against webinar endpoints.

How to Mitigate CVE-2025-31882

Immediate Actions Required

Update the WebinarPress plugin to a version later than 1.33.28 as soon as the vendor publishes a patched release.
Audit WordPress user accounts and remove or downgrade unnecessary Subscriber-level accounts.
Disable open user registration on sites that do not require it by setting Anyone can register to off under Settings > General.

Patch Information

The advisory documented by Patchstack tracks the fix for the broken access control issue in the WebinarPress plugin. Administrators should consult the Patchstack WordPress Plugin Vulnerability entry for the fixed version and upgrade guidance. Apply the vendor update through the WordPress plugin manager or via WP-CLI.

Workarounds

Deactivate the WebinarPress plugin until a patched release is installed if the plugin is not critical to site operations.
Restrict access to admin-ajax.php and plugin REST routes at the WAF layer for unauthenticated and Subscriber sessions.
Enforce strong authentication and multi-factor authentication for all WordPress accounts to raise the cost of obtaining the low-privilege access required for exploitation.

bash

# Update WebinarPress via WP-CLI once a patched version is available
wp plugin update wp-webinarsystem

# Temporarily deactivate the plugin as a workaround
wp plugin deactivate wp-webinarsystem

# Disable open registration
wp option update users_can_register 0