CVE-2019-25407: Comodo Dome Firewall XSS Vulnerability

CVE-2019-25407 Overview

CVE-2019-25407 is a reflected cross-site scripting (XSS) vulnerability affecting Comodo Dome Firewall version 2.7.0. The vulnerability exists in the backup schedule interface, where attackers can inject malicious JavaScript code through the BACKUP_RCPTTO parameter when submitting POST requests to the backupschedule endpoint. When successfully exploited, this allows arbitrary script execution within the context of authenticated users' browsers.

Critical Impact

Attackers can execute arbitrary JavaScript in the browsers of Comodo Dome Firewall administrators, potentially leading to session hijacking, credential theft, or unauthorized administrative actions on the firewall.

Affected Products

• Comodo Dome Firewall 2.7.0

Discovery Timeline

• 2026-02-19 - CVE CVE-2019-25407 published to NVD
• 2026-02-19 - Last updated in NVD database

Technical Details for CVE-2019-25407

Vulnerability Analysis

This reflected XSS vulnerability (CWE-79: Improper Neutralization of Input During Web Page Generation) arises from insufficient input validation in the Comodo Dome Firewall web management interface. The backupschedule endpoint accepts user-supplied data through the BACKUP_RCPTTO parameter without proper sanitization or encoding before reflecting it back to the user's browser.

When an attacker crafts a malicious POST request containing JavaScript code in the BACKUP_RCPTTO parameter, the firewall's web interface fails to escape or filter the input, causing the browser to interpret and execute the injected script. This vulnerability requires user interaction, as a victim must be tricked into clicking a malicious link or submitting a crafted form while authenticated to the firewall management console.

Root Cause

The root cause of this vulnerability is the lack of proper input validation and output encoding in the backup schedule functionality. The application directly incorporates user-supplied input from the BACKUP_RCPTTO parameter into the HTTP response without sanitizing special characters such as <, >, ", and ' that have syntactic meaning in HTML and JavaScript contexts. This violates the principle of never trusting user input and demonstrates a failure to implement context-aware output encoding.

Attack Vector

The attack is network-based and requires user interaction to succeed. An attacker would typically craft a malicious URL or hidden form that, when accessed by an authenticated administrator, sends a POST request to the /backupschedule endpoint with JavaScript payload embedded in the BACKUP_RCPTTO parameter. The attacker may distribute this via phishing emails, compromised websites, or social engineering tactics targeting firewall administrators. Upon execution, the malicious script runs with the privileges of the victim's session, potentially allowing the attacker to steal session cookies, perform administrative actions, or redirect the user to malicious sites.

For technical details on the exploitation technique, refer to the Exploit-DB #46408 entry and the VulnCheck Advisory.

Detection Methods for CVE-2019-25407

Indicators of Compromise

• Unusual POST requests to the /backupschedule endpoint containing script tags or JavaScript event handlers in the BACKUP_RCPTTO parameter
• HTTP logs showing encoded script payloads such as %3Cscript%3E or JavaScript event handlers like onerror=, onload= in request parameters
• Session anomalies indicating potential cookie theft or session hijacking following suspicious backup schedule page access
• Unexpected administrative actions performed shortly after users accessed external links

Detection Strategies

• Implement web application firewall (WAF) rules to detect and block common XSS payloads in POST parameters targeting the backupschedule endpoint
• Configure intrusion detection systems to alert on HTTP requests containing script injection patterns directed at Comodo Dome Firewall management interfaces
• Enable detailed logging of all HTTP requests to the firewall's web management interface for forensic analysis
• Deploy browser-based XSS auditors and Content Security Policy headers to reduce client-side execution risks

Monitoring Recommendations

• Monitor authentication logs for the Comodo Dome Firewall management interface for signs of session anomalies or unauthorized access
• Review web server access logs regularly for suspicious patterns in the BACKUP_RCPTTO parameter
• Implement network traffic analysis to detect outbound connections to unknown domains that may indicate data exfiltration following XSS exploitation
• Set up alerts for failed or unusual backup schedule configuration attempts

How to Mitigate CVE-2019-25407

Immediate Actions Required

• Restrict access to the Comodo Dome Firewall management interface to trusted internal networks only using network segmentation and firewall rules
• Implement a reverse proxy with WAF capabilities in front of the management interface to filter malicious requests
• Educate administrators about the risks of clicking untrusted links while authenticated to the firewall management console
• Consider disabling or restricting access to the backup schedule functionality until a patch is available

Patch Information

No official patch information is currently available from the vendor for this vulnerability. Organizations should contact Comodo directly for guidance on available updates or security fixes. Monitor the Comodo Firewall product page for security advisories and firmware updates that may address this issue.

Workarounds

• Deploy a Content Security Policy (CSP) header at the reverse proxy level to restrict inline script execution and mitigate XSS impact
• Use browser extensions that block JavaScript execution from untrusted sources when accessing the firewall management interface
• Implement HTTP-only and Secure flags on session cookies to prevent cookie theft through XSS attacks
• Limit administrative sessions to short timeouts to reduce the window of opportunity for session hijacking

# Example: Restricting access to management interface via iptables
# Allow management access only from trusted admin network
iptables -A INPUT -p tcp --dport 443 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -j DROP