CVE-2024-51640 Overview
CVE-2024-51640 is a Cross-Site Request Forgery (CSRF) vulnerability in the Matt Rude MDR Webmaster Tools WordPress plugin. The flaw affects all versions of mdr-webmaster-tools up to and including 1.1. The vulnerability is classified under CWE-352 and enables an attacker to chain CSRF with Stored Cross-Site Scripting (XSS).
An attacker can craft a malicious request that, when triggered by an authenticated administrator visiting an attacker-controlled page, modifies plugin settings to inject persistent JavaScript payloads. The injected script executes in the browser context of any subsequent visitor or administrator.
Critical Impact
Successful exploitation results in stored JavaScript execution within the WordPress administrative context, enabling session theft, privilege abuse, and persistent site compromise.
Affected Products
- Matt Rude MDR Webmaster Tools (mdr-webmaster-tools) WordPress plugin
- All versions from initial release through 1.1
- WordPress installations with the plugin enabled and accessible admin sessions
Discovery Timeline
- 2024-11-19 - CVE-2024-51640 published to the National Vulnerability Database
- 2026-04-23 - Last updated in NVD database
Technical Details for CVE-2024-51640
Vulnerability Analysis
The vulnerability combines two weaknesses into a single exploit chain. The plugin's settings handlers fail to verify request authenticity, and input fields are stored and later rendered without proper output encoding. An attacker can pre-stage a malicious HTML page that triggers a state-changing request against the plugin's configuration endpoint.
When a logged-in WordPress administrator loads the attacker's page, the browser submits the forged request using the administrator's authenticated session cookies. The plugin accepts the request because it lacks anti-CSRF token validation. The submitted payload, containing script content, is persisted to the WordPress database.
The stored payload executes whenever the affected plugin page is rendered. Execution occurs in the origin of the WordPress site, granting the script access to authentication cookies, the REST API, and any administrative function reachable from the browser.
Root Cause
The root cause is the absence of WordPress nonce verification on plugin settings submissions, combined with insufficient sanitization of user-supplied values. The plugin does not call check_admin_referer() or wp_verify_nonce() before processing input, and stored values are rendered without escaping through functions such as esc_attr() or esc_html().
Attack Vector
Exploitation requires user interaction from an authenticated administrator. The attacker hosts a page containing an auto-submitting form or fetch request targeting the vulnerable plugin endpoint. Social engineering, malvertising, or a watering-hole link delivers the victim to that page. The chain completes without any direct credential compromise.
The vulnerability is described in the Patchstack Vulnerability Report. No verified public proof-of-concept code is currently associated with this CVE.
Detection Methods for CVE-2024-51640
Indicators of Compromise
- Unexpected <script>, onerror=, or javascript: content stored within wp_options entries created by the mdr-webmaster-tools plugin.
- Administrator browser sessions generating outbound requests to unfamiliar domains immediately after visiting the WordPress admin dashboard.
- New or modified administrator accounts and unauthorized REST API calls originating from admin sessions.
Detection Strategies
- Inspect plugin settings rows in the WordPress database for HTML or JavaScript characters such as <, >, and quoted event handlers.
- Review web server access logs for POST requests to wp-admin/options-general.php or plugin-specific handlers lacking a valid _wpnonce parameter.
- Correlate referrer headers on settings-changing requests against expected admin workflows to surface cross-origin submissions.
Monitoring Recommendations
- Enable WordPress audit logging to capture plugin configuration changes with user, timestamp, and IP attribution.
- Deploy a web application firewall rule set that flags missing or invalid nonces on plugin administrative endpoints.
- Monitor browser Content Security Policy (CSP) violation reports for inline script execution within /wp-admin/ paths.
How to Mitigate CVE-2024-51640
Immediate Actions Required
- Deactivate and remove the MDR Webmaster Tools plugin until a patched release is published by the maintainer.
- Audit plugin settings stored in the database and remove any values containing executable HTML or JavaScript content.
- Invalidate active administrator sessions and rotate credentials for any account that accessed the WordPress admin while the plugin was installed.
Patch Information
At the time of publication, no fixed version of mdr-webmaster-tools is listed beyond 1.1. Consult the Patchstack advisory for the latest remediation status and replace the plugin with an actively maintained alternative if no update is available.
Workarounds
- Restrict access to /wp-admin/ using IP allow-listing or VPN-only access to reduce exposure to drive-by CSRF triggers.
- Enforce a strict Content Security Policy that disallows inline scripts within the WordPress administrative interface.
- Require administrators to use isolated browser profiles that do not retain authenticated WordPress sessions while browsing untrusted sites.
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
