CVE-2025-39594: Arigato Autoresponder XSS Vulnerability

CVE-2025-39594 Overview

CVE-2025-39594 is a reflected cross-site scripting (XSS) vulnerability in the Bob Arigato Autoresponder and Newsletter WordPress plugin (bft-autoresponder). The flaw affects all plugin versions up to and including 2.7.2.4. Attackers can inject malicious script content into web responses due to improper neutralization of user-supplied input during web page generation [CWE-79]. Successful exploitation requires user interaction, such as clicking a crafted link, and executes attacker-controlled JavaScript in the victim's browser session. The vulnerability has a network attack vector and does not require authentication, allowing remote attackers to target site administrators or visitors directly.

Critical Impact
Reflected XSS enables attackers to execute arbitrary JavaScript in victims' browsers, leading to session hijacking, credential theft, and unauthorized actions in the WordPress site context.

Affected Products

Bob Arigato Autoresponder and Newsletter plugin (bft-autoresponder) for WordPress
All versions from initial release through 2.7.2.4
WordPress installations running the vulnerable plugin

Discovery Timeline

2025-04-17 - CVE-2025-39594 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2025-39594

Vulnerability Analysis

The vulnerability is a reflected cross-site scripting flaw classified under [CWE-79]. The Arigato Autoresponder and Newsletter plugin accepts user-controlled input through HTTP request parameters and reflects that input into generated HTML responses without proper output encoding or input sanitization. An attacker crafts a malicious URL containing JavaScript payloads in vulnerable parameters. When a target user clicks the link, the server reflects the unsanitized payload into the rendered page, and the browser executes it within the site's origin.

The scope of the impact extends beyond the vulnerable component, indicating that injected scripts can affect resources in other security contexts within the WordPress instance. This allows attackers to perform actions on behalf of authenticated users, including administrators who interact with the malicious link.

Root Cause

The root cause is improper neutralization of input during web page generation. The plugin fails to apply context-aware output encoding (such as esc_html(), esc_attr(), or esc_url() from the WordPress API) before rendering user-supplied data back to the browser. Input validation routines do not strip or escape HTML special characters and JavaScript event handlers.

Attack Vector

The attack vector is network-based and requires user interaction. An attacker constructs a URL targeting a vulnerable plugin endpoint with JavaScript embedded in a request parameter. The attacker then delivers the URL through phishing emails, social media, or compromised websites. When a victim with an active WordPress session clicks the link, the payload executes in their browser context.

The vulnerability manifests when the plugin reflects parameter values into the response page without escaping. See the Patchstack Vulnerability Database entry for technical details.

Detection Methods for CVE-2025-39594

Indicators of Compromise

HTTP requests containing URL-encoded <script> tags, javascript: URIs, or event handler attributes (onerror=, onload=) targeting bft-autoresponder endpoints
Unusual referer headers from external domains pointing users to plugin pages with suspicious query strings
WordPress access logs showing reflected parameters containing HTML metacharacters such as <, >, ", and '
Unexpected administrative actions performed shortly after a user followed an external link

Detection Strategies

Deploy a web application firewall with rules to identify common XSS payload patterns in query parameters
Inspect WordPress access logs for requests to bft-autoresponder plugin paths containing encoded script content
Monitor browser-side Content Security Policy (CSP) violation reports for inline script execution attempts
Correlate phishing email indicators with subsequent WordPress session activity from the same user

Monitoring Recommendations

Enable verbose logging on the WordPress site and forward access logs to a centralized SIEM for analysis
Alert on parameter values exceeding normal length thresholds or containing suspicious character sequences
Track outbound requests from administrator browsers immediately following link clicks from external sources
Audit installed plugin versions regularly and flag instances of bft-autoresponder at or below version 2.7.2.4

How to Mitigate CVE-2025-39594

Immediate Actions Required

Identify all WordPress sites running the Arigato Autoresponder and Newsletter plugin and inventory the installed version
Update the plugin to a patched version above 2.7.2.4 as soon as a fixed release is available from the vendor
If no patched version exists, deactivate and remove the plugin until a fix is published
Force a password reset and session invalidation for administrators who may have interacted with suspicious links

Patch Information

As of the last NVD update on 2026-04-23, the advisory indicates the vulnerability affects versions through 2.7.2.4 with no confirmed fixed version listed in the available references. Review the Patchstack Vulnerability Database advisory for the latest patch status and apply vendor updates immediately upon release.

Workarounds

Disable the bft-autoresponder plugin until an official patch is available
Deploy a web application firewall configured to block reflected XSS payloads targeting WordPress endpoints
Implement a strict Content Security Policy that disallows inline scripts and restricts script sources to trusted origins
Train administrators to avoid clicking unsolicited links and to verify URLs before authenticating to WordPress

bash

# Example WordPress CLI commands to deactivate the vulnerable plugin
wp plugin list --name=bft-autoresponder --field=version
wp plugin deactivate bft-autoresponder
wp plugin delete bft-autoresponder