CVE-2025-24623: Really Simple SSL CSRF Vulnerability

CVE-2025-24623 Overview

CVE-2025-24623 is a Cross-Site Request Forgery (CSRF) vulnerability in the Really Simple SSL WordPress plugin (also known as Really Simple Security) developed by Really Simple Plugins. The flaw affects all versions of the plugin up to and including 9.1.4. An attacker can craft a malicious request that, when triggered by an authenticated user visiting an attacker-controlled page, performs unintended actions in the context of that user's session. The vulnerability is classified under CWE-352: Cross-Site Request Forgery and requires user interaction to succeed.

Critical Impact
Successful exploitation allows attackers to trigger unauthorized state-changing actions in the plugin on behalf of authenticated WordPress users, potentially altering security settings on sites relying on Really Simple SSL.

Affected Products

Really Simple Plugins — Really Simple SSL (really-simple-ssl)
All versions from n/a through 9.1.4
WordPress sites running the Really Simple Security plugin

Discovery Timeline

2025-01-24 - CVE-2025-24623 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-24623

Vulnerability Analysis

The vulnerability stems from missing or insufficient CSRF protections in one or more request handlers within the Really Simple SSL plugin. WordPress provides a nonce mechanism (wp_nonce_field, check_admin_referer, wp_verify_nonce) that plugins must use to validate the authenticity of state-changing requests. When these controls are absent or improperly implemented, attackers can construct requests that browsers automatically authenticate using the victim's existing session cookies.

The attack requires user interaction, meaning the target must click a link or visit a page controlled by the attacker while logged into WordPress. The scope remains unchanged and only integrity is affected — no confidentiality or availability impact is expected. This constrains the practical attack surface but still permits unauthorized modification of plugin settings that govern site SSL/security behavior.

Root Cause

The root cause is a failure to validate request authenticity in specific plugin endpoints handling privileged actions. Without a nonce or equivalent anti-CSRF token, WordPress cannot distinguish between a legitimate administrative action initiated inside the dashboard and a forged request triggered by a third-party site through the victim's browser.

Attack Vector

An attacker hosts a malicious page containing a hidden form or JavaScript that submits requests to a target WordPress site's Really Simple SSL endpoints. When an authenticated administrator visits that page, the browser attaches WordPress session cookies to the forged request, causing the plugin to process it as legitimate. Refer to the Patchstack advisory for technical specifics on the affected endpoints.

Detection Methods for CVE-2025-24623

Indicators of Compromise

Unexpected changes to Really Simple SSL plugin configuration or security settings without a corresponding administrator action in audit logs.
HTTP POST or GET requests to plugin endpoints containing an external Referer header that does not match the site's own domain.
Administrator sessions showing plugin actions immediately after visiting untrusted external sites.

Detection Strategies

Monitor WordPress access logs for requests to wp-admin/admin-ajax.php and plugin-specific endpoints that lack a valid nonce parameter.
Correlate off-site Referer headers with plugin state changes to identify potential forged requests.
Deploy a Web Application Firewall (WAF) rule that inspects Referer and Origin headers on plugin write operations.

Monitoring Recommendations

Enable WordPress audit logging plugins to record all administrative configuration changes with associated user, IP, and referrer data.
Review the Really Simple SSL settings periodically to confirm the configured security posture has not been altered.
Alert on administrator accounts that trigger plugin actions from unusual client fingerprints or geolocations.

How to Mitigate CVE-2025-24623

Immediate Actions Required

Update Really Simple SSL to a version later than 9.1.4 as soon as the vendor publishes a fixed release.
Restrict administrator browsing habits: administrators should not browse untrusted sites in the same browser session used to manage WordPress.
Audit recent plugin configuration changes to confirm no unauthorized modifications occurred prior to patching.

Patch Information

The vulnerability affects Really Simple SSL up to and including version 9.1.4. Consult the Patchstack advisory for the fixed version and vendor guidance. Apply updates through the WordPress plugin manager or via WP-CLI.

Workarounds

Deploy a WAF rule that blocks requests to Really Simple SSL endpoints when the Origin or Referer header does not match the site's domain.
Require administrators to use a dedicated browser or browser profile solely for WordPress administration.
Temporarily deactivate the plugin on high-value sites until the patched version is installed.

bash

# Update Really Simple SSL via WP-CLI once a patched version is available
wp plugin update really-simple-ssl

# Verify installed version
wp plugin get really-simple-ssl --field=version