CVE-2019-25416: Comodo Dome Firewall XSS Vulnerability

CVE-2019-25416 Overview

CVE-2019-25416 is a reflected Cross-Site Scripting (XSS) vulnerability affecting Comodo Dome Firewall version 2.7.0. The vulnerability exists in the QoS devices management endpoint, where the device parameter fails to properly sanitize user-supplied input before reflecting it back in HTTP responses. This allows attackers to inject malicious JavaScript code that executes in the context of authenticated users' browser sessions.

Critical Impact

Attackers can execute arbitrary JavaScript in administrators' browsers, potentially leading to session hijacking, credential theft, or unauthorized firewall configuration changes.

Affected Products

• Comodo Dome Firewall 2.7.0
• QoS devices management interface

Discovery Timeline

• 2026-02-19 - CVE-2019-25416 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2019-25416

Vulnerability Analysis

This reflected XSS vulnerability (CWE-79) occurs when user input submitted through the device parameter is echoed back to the browser without proper encoding or sanitization. The attack requires user interaction, specifically an administrator clicking a malicious link or submitting a crafted form that targets the vulnerable endpoint.

The vulnerability affects the QoS (Quality of Service) devices management functionality within the Comodo Dome Firewall administrative interface. When an attacker crafts a malicious POST request containing JavaScript payload in the device parameter, the firewall reflects this input directly into the response HTML without proper output encoding, causing the browser to execute the injected script.

Root Cause

The root cause is improper input validation and output encoding in the QoS devices management endpoint. The application fails to sanitize or encode special characters in the device parameter before including user-supplied data in the HTTP response, violating secure coding practices for preventing XSS attacks.

Attack Vector

The attack is network-based and requires user interaction. An attacker must convince a firewall administrator to click on a specially crafted link or visit a malicious page that submits a POST request to the vulnerable endpoint. The malicious script payload is embedded in the device parameter, and when the response is rendered, the injected JavaScript executes in the victim's browser with the same privileges as the authenticated session.

Since no verified code examples are available, the vulnerability can be understood as follows: an attacker constructs a POST request to the QoS devices management endpoint, embedding JavaScript code such as <script> tags within the device parameter value. When processed by the vulnerable endpoint, the script content is reflected in the response without encoding, causing browser execution. For detailed technical information, refer to the Exploit-DB entry #46408 or the VulnCheck Advisory.

Detection Methods for CVE-2019-25416

Indicators of Compromise

• Unusual POST requests to QoS devices management endpoints containing script tags or encoded JavaScript
• Web application logs showing device parameter values with HTML special characters (<, >, ", ')
• Browser-based attacks targeting firewall administrators through phishing emails or malicious websites

Detection Strategies

• Implement Web Application Firewall (WAF) rules to detect and block requests containing script injection patterns in POST parameters
• Monitor HTTP traffic for suspicious payloads in the device parameter, particularly those containing <script>, javascript:, or encoded variants
• Review web server access logs for POST requests to QoS management endpoints with anomalous parameter values

Monitoring Recommendations

• Enable detailed logging on the Comodo Dome Firewall administrative interface
• Configure alerts for multiple failed or suspicious requests to administrative endpoints
• Implement Content Security Policy (CSP) headers to mitigate the impact of any successful XSS exploitation

How to Mitigate CVE-2019-25416

Immediate Actions Required

• Restrict administrative interface access to trusted networks and IP addresses only
• Implement network segmentation to limit exposure of the firewall management interface
• Train administrators to recognize phishing attempts and avoid clicking suspicious links
• Deploy a Web Application Firewall (WAF) with XSS protection rules in front of the management interface

Patch Information

Organizations should contact Comodo for information regarding security patches or updated firmware versions that address this vulnerability. Review the Comodo Dome Firewall product page for the latest security updates and firmware releases.

Workarounds

• Disable or restrict access to the QoS devices management functionality if not required
• Implement strict Content Security Policy (CSP) headers to prevent inline script execution
• Use browser extensions or proxy tools to filter potentially malicious responses
• Require VPN access for all administrative interface connections to reduce attack surface

# Example: Restrict administrative interface access by IP (network firewall rule)
# Allow only specific trusted IP addresses to access the management interface
iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP