CVE-2025-23989 Overview
CVE-2025-23989 is a Cross-Site Request Forgery (CSRF) vulnerability [CWE-352] in the Alessandro Piconi Internal Link Builder plugin for WordPress. The flaw affects all versions of internal-link-builder up to and including 1.0. According to the Patchstack advisory, the CSRF weakness can be chained into a stored Cross-Site Scripting (XSS) condition. An attacker can trick an authenticated administrator into submitting a forged request that injects persistent script content into the site. Successful exploitation requires user interaction over the network and impacts confidentiality, integrity, and availability at a limited scope across security boundaries.
Critical Impact
A remote attacker can coerce an authenticated WordPress administrator into executing unauthorized actions that result in stored XSS, enabling persistent script execution in the admin context.
Affected Products
- Alessandro Piconi Internal Link Builder WordPress plugin
- All versions from initial release through 1.0
- WordPress sites with the internal-link-builder plugin installed and active
Discovery Timeline
- 2025-01-31 - CVE-2025-23989 published to the National Vulnerability Database
- 2026-04-23 - Last updated in the NVD database
Technical Details for CVE-2025-23989
Vulnerability Analysis
The vulnerability stems from missing or improper CSRF protection in administrative request handlers within the Internal Link Builder plugin. The plugin fails to validate WordPress nonces on state-changing endpoints. As a result, a crafted HTML page hosted on an attacker-controlled domain can issue authenticated requests to the target WordPress site when a logged-in administrator visits the page.
The Patchstack research classifies this as a CSRF-to-stored-XSS chain. The CSRF primitive submits attacker-controlled input that the plugin persists without adequate sanitization or output encoding. The stored payload then executes when administrators or other users render the affected admin views.
Root Cause
The root cause is the absence of anti-CSRF token verification, specifically wp_verify_nonce() or check_admin_referer() calls, on form submission and AJAX handlers in internal-link-builder version 1.0 and earlier. The handlers also lack proper input sanitization with functions such as wp_kses_post() or sanitize_text_field(), allowing script content to be stored in the database.
Attack Vector
The attack requires an authenticated WordPress administrator to visit an attacker-controlled page or click a malicious link while their session is active. The attacker hosts a page with an auto-submitting HTML form or asynchronous request targeting the vulnerable plugin endpoint. The forged request reuses the victim's session cookies due to the browser's ambient authority. The plugin processes the request as legitimate and stores the injected payload, which later executes in the browser of any user who loads the affected page.
No verified exploit code or public proof-of-concept is currently listed for this CVE. Refer to the Patchstack Vulnerability Report for further technical context.
Detection Methods for CVE-2025-23989
Indicators of Compromise
- Unexpected <script>, onerror, or onload attribute content stored in plugin-managed records or wp_options entries created by Internal Link Builder.
- WordPress administrator account activity originating from unusual referrers immediately preceding plugin configuration changes.
- New or modified entries in the plugin's database tables without corresponding entries in the WordPress audit log.
Detection Strategies
- Audit web server logs for POST requests to internal-link-builder admin endpoints that lack a same-origin Referer or Origin header.
- Inspect database content for HTML or JavaScript payloads in fields managed by the plugin.
- Review browser console errors and Content Security Policy reports for unexpected inline script execution on admin pages.
Monitoring Recommendations
- Enable WordPress audit logging to record administrator-initiated plugin setting changes and correlate with session origin.
- Monitor outbound requests from administrator browsers for callbacks to unknown domains, indicating possible XSS payload execution.
- Alert on installation of the internal-link-builder plugin at version 1.0 across managed WordPress fleets.
How to Mitigate CVE-2025-23989
Immediate Actions Required
- Deactivate and remove the Internal Link Builder plugin until a patched version is published by the vendor.
- Restrict administrator browsing habits and require fresh authentication for sensitive WordPress actions.
- Review and remove any malicious stored content from plugin-managed database fields and admin pages.
Patch Information
At the time of NVD publication, no fixed version of the Internal Link Builder plugin is listed. The advisory indicates the issue affects all versions through 1.0 with no patched release identified. Track the Patchstack Vulnerability Report for updates from the plugin author.
Workarounds
- Remove the plugin entirely if no patched release is available; this is the most reliable mitigation.
- Deploy a Web Application Firewall (WAF) rule to block requests to plugin admin endpoints that lack a valid Referer header matching the site origin.
- Enforce a strict Content Security Policy in the WordPress admin to limit inline script execution from injected payloads.
- Require administrators to log out of WordPress sessions before browsing untrusted sites.
# Remove the vulnerable plugin via WP-CLI
wp plugin deactivate internal-link-builder
wp plugin delete internal-link-builder
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
