CVE Alert: CVE-2025-9816 – veronalabs – WP Statistics – Simple, privacy-friendly Google Analytics alternative

Risk verdict

High risk: unauthenticated stored cross-site scripting via the User-Agent header could execute on visitors’ browsers.

Why this matters

Because no authentication is required, any visitor can trigger the payload, potentially compromising end-user sessions or data via client-side scripts. The impact is primarily on user experience and site trust, with limited server compromise, but widespread visitor-side scripting can still enable data exfiltration or defacement if sensitive pages are affected.

Most likely attack path

Attacker sends requests to a WordPress site running the vulnerable WP Statistics plugin with a crafted User-Agent header containing malicious script. The payload is stored due to insufficient sanitisation, and appears in pages rendered to users. As visitors load affected pages, the script executes in their browsers, enabling attacker-controlled actions without user interaction or elevated privileges; the scope metric suggests potential reach beyond the original component.

Who is most exposed

Sites running WordPress with WP Statistics <= 14.5.4, especially on shared hosting or publicly exposed endpoints, are at greatest risk. Organisations relying on this plugin for analytics are the primary targets.

Detection ideas

• Look for unusual or obfuscated HTML/JS fragments in User-Agent logs.
• WAF/IDS alerts for XSS payload patterns in User-Agent header.
• Review WP Statistics data stores for injected HTML/JS content.
• User reports of unexpected page scripts or console errors on analytics-related pages.
• Correlate spikes in traffic to pages rendering plugin content.

Mitigation and prioritisation

• Patch immediately: upgrade to a non-vulnerable WP Statistics version or remove the plugin.
• Apply compensating controls: enable a strict Content Security Policy; ensure HttpOnly cookies; block inline scripts; harden input handling at the plugin level.
• Deploy WAF rules to filter suspicious User-Agent payloads and monitor for repeated attempts.
• Plan a controlled upgrade in staging; verify compatibility before production rollout; maintain backups.