CVE-2024-56037: User Referral Plugin XSS Vulnerability

CVE-2024-56037 Overview

CVE-2024-56037 is a reflected Cross-Site Scripting (XSS) vulnerability in the SoftClever Limited User Referral plugin (user-referral-free) for WordPress. The flaw stems from improper neutralization of user-supplied input during web page generation [CWE-79]. Attackers can craft a malicious URL that, when clicked by an authenticated or unauthenticated user, executes arbitrary JavaScript in the victim's browser session. The vulnerability affects all plugin versions up to and including 8.0. Successful exploitation can lead to session hijacking, credential theft, and unauthorized actions performed in the context of the victim.

Critical Impact
A reflected XSS payload delivered via a crafted link can execute arbitrary scripts in the victim's browser, enabling session theft and content manipulation across a scope-changed boundary.

Affected Products

SoftClever Limited User Referral (user-referral-free) WordPress plugin
All versions from initial release through 8.0
WordPress sites with the vulnerable plugin installed and activated

Discovery Timeline

2025-01-02 - CVE-2024-56037 published to NVD
2026-04-23 - Last updated in NVD database

Technical Details for CVE-2024-56037

Vulnerability Analysis

The User Referral plugin fails to sanitize and encode user-controlled input before reflecting it into HTTP responses. When a victim follows a crafted URL containing a JavaScript payload, the plugin renders the payload directly into the resulting HTML page. The browser then parses and executes the script in the origin of the affected WordPress site.

The attack requires user interaction, typically through phishing or social engineering, to deliver the malicious link. Because the vulnerability operates over a scope-changed boundary, the executed script can affect resources beyond the vulnerable component, including authenticated administrator sessions if an admin clicks the link.

Root Cause

The root cause is missing output encoding and input validation on parameters reflected back into rendered pages. The plugin does not apply WordPress sanitization functions such as esc_html(), esc_attr(), or wp_kses() to user-controlled values before echoing them into the response body.

Attack Vector

The attack is delivered over the network without authentication. An attacker constructs a URL pointing to the vulnerable endpoint with an injected payload in a query parameter. When a victim visits the URL, the unsanitized payload renders inline and executes. The vulnerability mechanism is documented in the Patchstack WordPress Vulnerability Report.

Detection Methods for CVE-2024-56037

Indicators of Compromise

Web server access logs containing HTTP requests to plugin endpoints with <script>, onerror=, javascript:, or URL-encoded equivalents in query parameters
Outbound browser requests to attacker-controlled domains originating from sessions tied to the WordPress site
Unexpected administrative actions or new user accounts created shortly after an admin clicked an external link

Detection Strategies

Inspect HTTP request and referrer logs for reflected payload patterns targeting user-referral-free endpoints
Deploy Web Application Firewall (WAF) signatures that flag XSS payload patterns in query strings on WordPress installations
Correlate phishing email telemetry with clicks on links pointing to WordPress hosts running the vulnerable plugin

Monitoring Recommendations

Enable detailed access logging on the WordPress site and forward to a centralized logging platform for query-string analysis
Monitor browser security headers including Content Security Policy (CSP) violation reports for blocked inline script execution
Alert on changes to WordPress administrator accounts, user roles, and plugin configurations

How to Mitigate CVE-2024-56037

Immediate Actions Required

Identify all WordPress installations running the user-referral-free plugin at version 8.0 or earlier
Deactivate and remove the plugin if a patched version is not yet available from the vendor
Apply WAF rules that block common reflected XSS payload patterns targeting the plugin's endpoints

Patch Information

At the time of NVD publication, the advisory lists affected versions up to and including 8.0. Administrators should consult the Patchstack WordPress Vulnerability Report for the latest patch status and upgrade to a fixed release once published by SoftClever Limited.

Workarounds

Disable the User Referral plugin until a vendor patch is released and verified
Enforce a strict Content Security Policy that disallows inline scripts and untrusted external script sources
Train administrators and editors to avoid clicking unverified links to the WordPress site, particularly from email or chat
Restrict administrative access to known IP ranges to reduce exposure of privileged sessions to reflected attacks

bash

# Example: list and deactivate the vulnerable plugin via WP-CLI
wp plugin list --name=user-referral-free --fields=name,status,version
wp plugin deactivate user-referral-free
wp plugin delete user-referral-free