CVE-2025-30934: OLIVESYSTEM Plugin Auth Bypass Flaw

CVE-2025-30934 Overview

CVE-2025-30934 is a Missing Authorization vulnerability [CWE-862] affecting the OLIVESYSTEM 診断ジェネレータ作成プラグイン (os-diagnosis-generator) WordPress plugin. The flaw allows unauthenticated attackers to access functionality that is not properly constrained by Access Control Lists (ACLs). All plugin versions up to and including 1.4.16 are affected. The vulnerability is exploitable remotely over the network without user interaction or authentication, impacting the integrity of the affected WordPress site.

Critical Impact
Unauthenticated attackers can invoke restricted plugin functionality on WordPress sites running os-diagnosis-generator <= 1.4.16, enabling unauthorized modification of plugin-controlled data.

Affected Products

OLIVESYSTEM 診断ジェネレータ作成プラグイン (os-diagnosis-generator)
Versions: from n/a through 1.4.16
WordPress installations with the os-diagnosis-generator plugin enabled

Discovery Timeline

2025-06-06 - CVE-2025-30934 published to the National Vulnerability Database (NVD)
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-30934

Vulnerability Analysis

The vulnerability stems from missing authorization checks in one or more request handlers exposed by the os-diagnosis-generator plugin. The plugin registers endpoints that perform privileged actions but fails to verify the caller's role, capability, or nonce before executing the action. As a result, requests originating from unauthenticated visitors reach code paths that should be limited to administrators or authorized editors.

The issue is classified under [CWE-862] Missing Authorization. It falls into the Broken Access Control category and does not require elevated privileges, user interaction, or authenticated sessions to exploit. The confidentiality impact is none, integrity impact is low, and availability impact is none, indicating that attackers can modify limited plugin state without accessing sensitive data or crashing the service.

Root Cause

The root cause is the absence of capability checks such as current_user_can() and nonce verification via check_admin_referer() or wp_verify_nonce() on plugin action handlers. WordPress plugins that register admin-post.php, admin-ajax.php, or REST endpoints must explicitly enforce authorization on each callback. The os-diagnosis-generator plugin omits these checks on at least one restricted function.

Attack Vector

The attack vector is network-based. An attacker sends a crafted HTTP request to the affected WordPress site targeting the vulnerable plugin endpoint. Because no authentication or authorization is enforced, the request executes with the privileges intended for legitimate administrative actions. Exploitation requires knowledge of the endpoint path and expected parameters, both of which can be recovered from the plugin's public source code.

No public proof-of-concept exploit has been published. The EPSS probability is 0.257% (percentile 17.1), indicating low current exploitation likelihood. Refer to the Patchstack WordPress Vulnerability Advisory for additional technical context.

Detection Methods for CVE-2025-30934

Indicators of Compromise

Unauthenticated HTTP POST or GET requests to admin-ajax.php or admin-post.php referencing os-diagnosis-generator actions.
Unexpected modifications to plugin-managed content, diagnosis generator templates, or plugin option values.
Access log entries showing requests to plugin endpoints from external IP addresses lacking a valid authenticated session cookie.

Detection Strategies

Review WordPress access logs for requests targeting os-diagnosis-generator action handlers that lack a wp_nonce parameter or authenticated cookie.
Enable WordPress audit logging to capture option changes, post creations, and metadata updates attributable to the plugin.
Deploy Web Application Firewall (WAF) rules that flag anonymous requests to plugin-specific action= parameters.

Monitoring Recommendations

Monitor changes to plugin database tables and wp_options entries associated with os-diagnosis-generator.
Alert on spikes of 4xx or 2xx responses from the plugin endpoint originating from a single IP or user agent.
Correlate WordPress activity logs with edge access logs to identify anonymous invocation of privileged plugin actions.

How to Mitigate CVE-2025-30934

Immediate Actions Required

Upgrade the os-diagnosis-generator plugin to a version later than 1.4.16 once the vendor publishes a fix.
If no patch is available, deactivate and remove the plugin from all WordPress sites where it is installed.
Audit WordPress content and plugin settings for unauthorized changes made since the plugin was installed.

Patch Information

At the time of publication, versions through 1.4.16 are affected and no fixed version is listed in the enriched advisory data. Consult the Patchstack WordPress Vulnerability Advisory for the latest vendor patch status and update guidance.

Workarounds

Restrict access to WordPress administrative endpoints such as admin-ajax.php and admin-post.php at the WAF or reverse proxy layer using IP allow-lists.
Apply virtual patching rules that require an authenticated session cookie for requests invoking os-diagnosis-generator action parameters.
Remove the plugin entirely if the diagnosis generator functionality is not required for site operations.

bash

# Example: block unauthenticated requests to the plugin action at the nginx layer
location = /wp-admin/admin-ajax.php {
    if ($arg_action ~* "os_diagnosis_generator") {
        if ($http_cookie !~* "wordpress_logged_in") {
            return 403;
        }
    }
    include fastcgi_params;
    fastcgi_pass php_upstream;
}