CVE-2024-51642 Overview
CVE-2024-51642 is a Cross-Site Request Forgery (CSRF) vulnerability [CWE-352] in the Seo Free WordPress plugin by ivan9146. The flaw affects all versions from initial release through version 1.4. Attackers can chain the CSRF weakness with stored Cross-Site Scripting (XSS) to persist malicious JavaScript inside the affected WordPress site. Successful exploitation requires an authenticated user to interact with an attacker-controlled page, after which the injected payload executes in the browser of every visitor who renders the affected output.
Critical Impact
A successful attack stores attacker-controlled JavaScript in the WordPress site, enabling session theft, administrative action abuse, and downstream compromise of site visitors.
Affected Products
- ivan9146 Seo Free WordPress plugin versions through 1.4
- WordPress installations with the seo-free plugin active
- Site administrators and editors authenticated to the WordPress admin interface
Discovery Timeline
- 2024-11-19 - CVE-2024-51642 published to the National Vulnerability Database
- 2026-04-23 - Last updated in NVD database
Technical Details for CVE-2024-51642
Vulnerability Analysis
The Seo Free plugin exposes one or more state-changing endpoints that do not validate a CSRF token (nonce). An authenticated administrator who visits an attacker-controlled web page triggers a forged request to the plugin. The request submits attacker-supplied content that the plugin stores without proper sanitization or output encoding. When the stored content is later rendered, the browser executes the embedded JavaScript in the context of the WordPress site.
This attack class combines two weaknesses: missing request origin validation and unsafe handling of user-controlled input. The chained outcome is persistent script execution against any user who loads the affected page, including site visitors and other administrators.
Root Cause
The root cause is the absence of WordPress nonce verification on plugin form handlers, typically the lack of a check_admin_referer() or wp_verify_nonce() call before processing submitted data. Compounding the issue, the plugin stores the submitted values and emits them in HTML without applying esc_html(), esc_attr(), or wp_kses() filtering, enabling stored XSS.
Attack Vector
Exploitation requires user interaction over the network. An attacker hosts a malicious page containing an auto-submitting form or image tag targeting the vulnerable plugin endpoint. When an authenticated WordPress administrator visits the page, the browser sends the forged request with valid session cookies. The plugin accepts the request and persists the attacker's payload. Any subsequent rendering of that data triggers the stored script in the victim's browser. The vulnerability carries an EPSS probability of 0.206%. Technical details are available in the Patchstack WordPress Vulnerability Advisory.
Detection Methods for CVE-2024-51642
Indicators of Compromise
- Unexpected <script>, onerror, or onload attributes appearing in plugin-managed settings or post metadata associated with seo-free
- WordPress admin POST requests to seo-free endpoints originating from external Referer headers
- New or modified plugin options containing encoded JavaScript such as <script> or javascript: URIs
Detection Strategies
- Inspect the WordPress wp_options table and plugin-specific tables for stored values containing HTML or script tokens
- Review web server access logs for state-changing requests to wp-admin paths handled by the seo-free plugin that lack a valid Referer from the same origin
- Run static checks against plugin output rendered in administrative dashboards and public-facing pages for unescaped content
Monitoring Recommendations
- Alert on outbound requests from administrator browsers to unfamiliar domains shortly after WordPress admin logins
- Monitor for plugin configuration changes performed outside scheduled maintenance windows
- Forward WordPress audit logs and web server logs to a centralized analytics platform for correlation across users, IPs, and request patterns
How to Mitigate CVE-2024-51642
Immediate Actions Required
- Deactivate and remove the Seo Free plugin if a patched version is not available for your environment
- Audit all plugin-managed content and admin options for injected scripts and revert any unauthorized changes
- Rotate WordPress administrator credentials and invalidate active sessions if compromise is suspected
Patch Information
No fixed version is identified in the advisory. The vulnerability affects Seo Free through version 1.4. Consult the Patchstack WordPress Vulnerability Advisory for current remediation guidance and any vendor updates.
Workarounds
- Restrict access to wp-admin by IP allowlist at the web server or WAF layer to limit CSRF opportunity
- Enforce a strict Content Security Policy (CSP) that blocks inline scripts and unknown script sources on the WordPress front end
- Require administrators to use separate browsers or browser profiles for WordPress management to reduce cross-site request exposure
- Apply a virtual patch via a Web Application Firewall to block requests to seo-free endpoints that lack a valid WordPress nonce
# Configuration example: enforce CSP and disable the vulnerable plugin via WP-CLI
wp plugin deactivate seo-free
wp plugin delete seo-free
# Add a restrictive CSP header in the web server configuration
# Apache example:
# Header set Content-Security-Policy "default-src 'self'; script-src 'self'; object-src 'none'; frame-ancestors 'self'"
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
