CVE-2025-46438: GTDB Guitar Tuners Stored XSS Vulnerability

CVE-2025-46438 Overview

CVE-2025-46438 is a stored cross-site scripting (XSS) vulnerability in the warmwhisky GTDB Guitar Tuners WordPress plugin (guitar-tuner). The flaw affects all versions up to and including 4.2.2. Attackers with low-privilege authenticated access can inject persistent JavaScript that executes in the browsers of users who view the affected pages. The vulnerability is tracked under CWE-79: Improper Neutralization of Input During Web Page Generation.

Critical Impact
Successful exploitation allows an authenticated attacker to store malicious scripts that execute in victim browsers, enabling session theft, credential harvesting, and administrative account takeover through a scope-changing payload.

Affected Products

warmwhisky GTDB Guitar Tuners WordPress plugin (guitar-tuner)
All versions from n/a through <= 4.2.2
WordPress installations with the plugin activated

Discovery Timeline

2025-04-24 - CVE-2025-46438 published to NVD by Patchstack
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-46438

Vulnerability Analysis

The vulnerability stems from improper neutralization of user-supplied input rendered within plugin-generated web pages. An authenticated user with low privileges can submit crafted input containing HTML or JavaScript payloads. The plugin stores this input and later renders it without adequate sanitization or output encoding. When another user loads the affected page, the payload executes within their browser session.

Because the scope is changed during exploitation, the injected script can affect resources beyond the vulnerable component, including the WordPress administrator context. The confidentiality, integrity, and availability impacts are limited but real, and user interaction is required for the payload to trigger.

Root Cause

The root cause is missing or insufficient input validation and output escaping in the guitar-tuner plugin code paths that accept and render user-controllable data. WordPress provides sanitization APIs such as wp_kses_post(), esc_html(), and esc_attr(), but the affected code paths do not apply appropriate filters before persisting or emitting data to the DOM.

Attack Vector

Exploitation requires network access to the WordPress site, a low-privileged authenticated account, and interaction from a target user who loads the affected page. The attacker submits a payload containing script tags or event handlers through a plugin input field. The stored payload executes when victims visit the rendered page, allowing session cookie theft, forced administrative actions, and pivot to further site compromise.

Refer to the Patchstack XSS Vulnerability Advisory for additional technical context.

Detection Methods for CVE-2025-46438

Indicators of Compromise

Unexpected <script> tags, onerror, onload, or javascript: URIs stored in wp_posts, wp_postmeta, or plugin-specific database tables
New or modified WordPress administrator accounts appearing shortly after plugin content edits
Outbound requests from admin browsers to unfamiliar domains after loading plugin-rendered pages
Web server logs showing POST requests to guitar-tuner plugin endpoints from low-privilege authenticated sessions

Detection Strategies

Audit plugin-managed database entries for HTML entities and script constructs that should not appear in tuner configuration data
Correlate authenticated POST activity to plugin routes with subsequent DOM-based script execution telemetry from monitored endpoints
Deploy content security policy (CSP) reporting to surface inline script violations originating from plugin pages

Monitoring Recommendations

Enable WordPress audit logging for content modifications by non-administrator roles
Monitor admin panel sessions for anomalous XHR or fetch calls issued from plugin-rendered views
Alert on privilege changes, user creation events, and plugin/theme installations following suspicious editor activity

How to Mitigate CVE-2025-46438

Immediate Actions Required

Deactivate the GTDB Guitar Tuners plugin until a patched release is confirmed installed
Review all existing plugin content for previously stored malicious payloads and remove them from the database
Rotate WordPress administrator credentials and invalidate active sessions if exploitation is suspected
Restrict which user roles can access the plugin's content editing endpoints

Patch Information

As of publication, the advisory identifies affected versions up to and including 4.2.2. Consult the Patchstack advisory and the plugin vendor for a fixed release. Apply the vendor patch as soon as it becomes available and verify the plugin version reported in the WordPress admin dashboard.

Workarounds

Remove or disable the guitar-tuner plugin on production sites until a fix is deployed
Deploy a web application firewall (WAF) rule that blocks script tags and event handler attributes in requests targeting plugin endpoints
Enforce a strict Content Security Policy that disallows inline scripts on pages rendering plugin output
Limit contributor and author roles from accessing the plugin's editing interfaces

bash

# Example: disable the plugin via WP-CLI while awaiting a patched release
wp plugin deactivate guitar-tuner
wp plugin status guitar-tuner

# Example: search the database for stored script payloads in plugin content
wp db query "SELECT ID, post_title FROM wp_posts WHERE post_content LIKE '%<script%' OR post_content LIKE '%onerror=%';"