CVE-2025-30811: ValidateCertify CSRF Vulnerability

CVE-2025-30811 Overview

CVE-2025-30811 is a Cross-Site Request Forgery (CSRF) vulnerability [CWE-352] in the ValidateCertify WordPress plugin developed by Javier Revilla. The plugin, distributed as validar-certificados-de-cursos, allows website operators to validate course completion certificates. The flaw affects all versions from initial release through 1.6.1. An attacker can craft a malicious web page that triggers unauthorized state-changing requests when an authenticated administrator visits it. The vulnerability requires user interaction and does not require attacker authentication, making phishing-based exploitation practical against WordPress site administrators.

Critical Impact
Successful exploitation permits attackers to perform unauthorized actions in the context of an authenticated ValidateCertify user, resulting in limited integrity impact on the affected WordPress site.

Affected Products

Javier Revilla ValidateCertify (validar-certificados-de-cursos) WordPress plugin
All versions from initial release through 1.6.1
WordPress installations running the vulnerable plugin

Discovery Timeline

2025-03-27 - CVE-2025-30811 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-30811

Vulnerability Analysis

The ValidateCertify plugin exposes one or more state-changing endpoints that lack anti-CSRF token validation. WordPress provides the wp_nonce_field() and check_admin_referer() mechanisms to bind sensitive requests to a specific user session. The plugin omits these checks on privileged actions through version 1.6.1.

An attacker who convinces an authenticated administrator to visit a crafted page can trigger requests that the browser transmits with the victim's session cookies. The server processes the requests as if the administrator initiated them. The attack vector is network-based and requires user interaction, but no attacker credentials.

The impact is limited to integrity, with no direct confidentiality or availability effects reported. Depending on which plugin actions are exposed, an attacker could modify plugin settings or manipulate certificate validation data.

Root Cause

The root cause is missing CSRF protection on privileged HTTP handlers within the plugin. Requests are accepted based solely on cookie-based session authentication, without a per-request unpredictable token. This violates the standard WordPress security pattern for administrator-facing actions.

Attack Vector

Exploitation proceeds through social engineering. The attacker hosts a page containing an auto-submitting HTML form or an image tag that issues a request to the vulnerable plugin endpoint. When a logged-in WordPress administrator loads the page in the same browser session, the browser attaches authentication cookies and the plugin executes the forged action. For technical details, see the Patchstack CSRF Vulnerability Report.

Detection Methods for CVE-2025-30811

Indicators of Compromise

Unexpected changes to ValidateCertify plugin configuration or stored certificate records
HTTP POST requests to plugin endpoints with Referer headers pointing to external domains
Administrator sessions performing plugin actions immediately after visiting external links
Absence of _wpnonce or _wp_http_referer parameters in submitted plugin requests

Detection Strategies

Review web server access logs for requests to validar-certificados-de-cursos endpoints with cross-origin Referer values
Correlate administrator authentication events with subsequent state-changing plugin requests
Alert on plugin configuration changes that occur without a corresponding admin console navigation trail

Monitoring Recommendations

Enable WordPress audit logging to capture plugin option updates and administrative actions
Monitor for anomalous outbound clicks from administrator workstations to untrusted domains
Track the plugin version installed across managed WordPress sites and flag versions at or below 1.6.1

How to Mitigate CVE-2025-30811

Immediate Actions Required

Update the ValidateCertify plugin to a version above 1.6.1 once the vendor publishes a fix
Deactivate and remove the validar-certificados-de-cursos plugin if no patched version is available
Require administrators to log out of WordPress before browsing untrusted sites
Restrict WordPress administrator accounts to dedicated browsing profiles or sessions

Patch Information

At the time of publication, the CVE record identifies all versions through 1.6.1 as affected. Site operators should consult the Patchstack CSRF Vulnerability Report and the plugin's WordPress.org repository for updated release information.

Workarounds

Deploy a web application firewall rule that blocks requests to plugin endpoints when the Referer header is missing or points outside the site's origin
Enforce SameSite=Strict or SameSite=Lax cookie attributes on WordPress authentication cookies
Limit administrator role assignments to reduce the number of accounts that can trigger the vulnerable actions
Remove the plugin from production sites until a patched release is available

bash

# Example ModSecurity rule blocking cross-origin POSTs to the vulnerable plugin
SecRule REQUEST_URI "@contains /wp-admin/admin.php" \
  "chain,phase:2,deny,status:403,id:1030811,\
   msg:'CVE-2025-30811: Blocking cross-origin request to ValidateCertify'"
  SecRule ARGS:page "@streq validar-certificados-de-cursos" "chain"
  SecRule REQUEST_HEADERS:Referer "!@beginsWith https://your-site.example/"