CVE-2019-25415: Comodo Dome Firewall XSS Vulnerability

CVE-2019-25415 Overview

CVE-2019-25415 is a reflected cross-site scripting (XSS) vulnerability in Comodo Dome Firewall version 2.7.0. The flaw resides in the hotspot_permanent_users endpoint, which fails to sanitize input submitted through the MACADDRESSES parameter. Attackers can craft a POST request containing JavaScript payloads that execute in the browser of an authenticated administrator who is induced to interact with a malicious link or form. The weakness is tracked as [CWE-79] Improper Neutralization of Input During Web Page Generation. Successful exploitation can hijack administrative sessions, alter firewall configuration, or pivot into the underlying management interface.

Critical Impact
Attackers can execute arbitrary JavaScript in an administrator's browser session, enabling session theft and unauthorized configuration changes on the firewall.

Affected Products

Comodo Dome Firewall 2.7.0
hotspot_permanent_users web management endpoint
Deployments exposing the management interface to untrusted networks

Discovery Timeline

2026-02-19 - CVE-2019-25415 published to NVD
2026-02-20 - Last updated in NVD database

Technical Details for CVE-2019-25415

Vulnerability Analysis

The vulnerability is a reflected XSS issue in the Comodo Dome Firewall web management console. The hotspot_permanent_users handler accepts user-supplied values through the MACADDRESSES POST parameter and echoes them into the rendered HTML response without proper encoding or sanitization. Because the response is generated server-side using attacker-controlled input, any script payload embedded in the parameter executes in the context of the firewall management origin. Exploitation requires user interaction, since the victim must follow an attacker-crafted link or submit a malicious form while logged into the firewall. The vulnerability does not require authentication on the attacker side and is reachable across the network.

Root Cause

The root cause is missing output encoding on the MACADDRESSES parameter handled by the hotspot_permanent_users endpoint. Input from the HTTP request body flows directly into the HTML response, breaking the boundary between data and executable script content.

Attack Vector

An attacker delivers a crafted HTTP POST request, typically through a phishing link or an attacker-controlled page that auto-submits a form. When an authenticated administrator triggers the request, the firewall reflects the malicious MACADDRESSES value into the response page. The browser then executes the injected JavaScript under the firewall's origin, allowing the attacker to read session cookies, issue authenticated requests, or modify the rendered DOM. Technical exploitation details are documented in the Exploit-DB #46408 entry and the VulnCheck Comodo XSS Advisory.

Detection Methods for CVE-2019-25415

Indicators of Compromise

POST requests to /hotspot_permanent_users containing HTML or JavaScript metacharacters such as <script>, onerror=, or javascript: inside the MACADDRESSES parameter
HTTP referer headers from external domains submitting authenticated form data to the firewall management interface
Unexpected administrative configuration changes following an admin web session

Detection Strategies

Inspect web server and proxy logs for POST requests to hotspot_permanent_users containing encoded or raw script tags in MACADDRESSES
Deploy a web application firewall rule that flags reflected payloads where request parameter values appear unchanged in the response body
Correlate administrator browser sessions with anomalous outbound requests to attacker-controlled domains shortly after firewall logins

Monitoring Recommendations

Restrict and log all access to the firewall management interface, alerting on connections from outside an approved administrator subnet
Monitor for repeated 4xx or 5xx responses on the hotspot_permanent_users endpoint that may indicate fuzzing or payload tuning
Enable browser-side content security policy reporting on the management console to surface blocked script executions

How to Mitigate CVE-2019-25415

Immediate Actions Required

Restrict access to the Comodo Dome Firewall management interface to a dedicated administrator network or VPN segment
Require administrators to use a hardened, dedicated browser profile for firewall management to reduce cross-site interaction risk
Review recent administrator sessions and configuration changes for signs of unauthorized modification

Patch Information

No vendor advisory or patched version is referenced in the NVD entry for CVE-2019-25415. Organizations running Comodo Dome Firewall 2.7.0 should contact Comodo for upgrade guidance through the Comodo Dome Firewall product page and consider migrating to a supported firewall platform if no fix is available.

Workarounds

Block external access to the hotspot_permanent_users endpoint at an upstream reverse proxy or web application firewall
Implement a WAF rule that strips or rejects HTML and JavaScript metacharacters in the MACADDRESSES POST parameter
Train administrators to avoid clicking external links while authenticated to the firewall and to log out immediately after configuration tasks

bash

# Example WAF rule (ModSecurity) to block script payloads in MACADDRESSES
SecRule REQUEST_URI "@contains /hotspot_permanent_users" \
  "phase:2,chain,deny,status:403,id:1002501,msg:'Reflected XSS attempt CVE-2019-25415'"
  SecRule ARGS:MACADDRESSES "@rx (?i)(<script|javascript:|onerror=|onload=)" "t:none"