CVE-2025-31456 Overview
CVE-2025-31456 is a Cross-Site Request Forgery (CSRF) vulnerability in the bsndev Ultimate Security Checker plugin for WordPress. The flaw affects all versions of the plugin up to and including 4.2. An attacker can trick an authenticated user into submitting a forged request that triggers a security rescan operation without the user's consent. The vulnerability is classified under [CWE-352] and requires user interaction, such as visiting an attacker-controlled page, to succeed.
Critical Impact
Attackers can force authenticated WordPress users to trigger unintended security rescan actions through crafted requests, resulting in limited integrity impact on the affected site.
Affected Products
- bsndev Ultimate Security Checker plugin for WordPress
- All versions from n/a through 4.2
- WordPress sites with the vulnerable plugin installed and active
Discovery Timeline
- 2025-03-28 - CVE-2025-31456 published to NVD
- 2026-06-17 - Last updated in NVD database
Technical Details for CVE-2025-31456
Vulnerability Analysis
The Ultimate Security Checker plugin fails to validate the origin or authenticity of state-changing HTTP requests. The plugin lacks proper CSRF token verification on its security rescan endpoint. An attacker crafts a malicious web page containing a forged request targeting the plugin's rescan action. When an authenticated administrator visits the attacker-controlled page, the browser automatically submits the request using the victim's active session cookies.
The attack succeeds because the plugin trusts the authenticated session without confirming user intent. This class of vulnerability falls under [CWE-352] Cross-Site Request Forgery. The EPSS data indicates a low probability of exploitation in the near term, though the attack pattern is well understood.
Root Cause
The root cause is the absence of anti-CSRF protections such as WordPress nonce validation on the plugin's rescan handler. WordPress provides the wp_nonce_field() and check_admin_referer() functions to prevent this class of vulnerability. The plugin does not enforce these checks on the affected action, allowing arbitrary cross-origin requests to succeed when accompanied by a valid session cookie.
Attack Vector
Exploitation requires an attacker to deliver a crafted link or page to an authenticated WordPress user, typically an administrator. Common delivery methods include phishing emails, malicious advertisements, or forum posts linking to attacker-controlled content. The victim's browser transmits authentication cookies with the forged request, causing the plugin to execute the rescan action as the victim. The impact is limited to integrity: attackers cannot directly read data or crash the site through this vector, but they can force unwanted administrative actions. Refer to the Patchstack Vulnerability Report for additional technical details.
Detection Methods for CVE-2025-31456
Indicators of Compromise
- Unexpected security rescan events in WordPress admin activity logs without corresponding user actions
- HTTP requests to the Ultimate Security Checker plugin endpoints with Referer headers pointing to external or unknown domains
- Rescan operations initiated during unusual hours or from admin sessions that were browsing external content
Detection Strategies
- Review web server access logs for POST requests targeting Ultimate Security Checker action handlers with mismatched or missing Referer and Origin headers
- Enable WordPress audit logging plugins to record all plugin-triggered administrative actions and associate them with source URLs
- Correlate rescan trigger events with administrator browser sessions and external navigation events
Monitoring Recommendations
- Monitor the WordPress wp-admin directory for anomalous POST activity targeting the vulnerable plugin
- Alert on requests to the plugin's rescan endpoint that lack expected nonce parameters
- Track administrator session activity for signs of concurrent external navigation followed by plugin state changes
How to Mitigate CVE-2025-31456
Immediate Actions Required
- Deactivate the Ultimate Security Checker plugin until a patched version is confirmed available from the vendor
- Restrict WordPress administrator accounts from browsing untrusted content while logged in
- Audit recent plugin activity to identify any unauthorized rescan events
Patch Information
At the time of NVD publication, the vulnerability affects Ultimate Security Checker versions up to and including 4.2. No fixed version is listed in the available advisory data. Site administrators should consult the Patchstack Vulnerability Report for the latest patch status and vendor guidance.
Workarounds
- Remove or deactivate the Ultimate Security Checker plugin from affected WordPress installations
- Deploy a web application firewall rule that blocks cross-origin POST requests to the plugin's action endpoints
- Enforce SameSite=Strict or SameSite=Lax cookie attributes on WordPress session cookies to reduce CSRF exposure
- Require administrators to use separate browser profiles or sessions for WordPress administration
# Configuration example: disable the vulnerable plugin via WP-CLI
wp plugin deactivate ultimate-security-checker
wp plugin delete ultimate-security-checker
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
