CVE-2019-25402
📋 TL;DR
Comodo Dome Firewall 2.7.0 contains a reflected cross-site scripting vulnerability in the login page's username parameter. Unauthenticated attackers can inject malicious JavaScript that executes in victims' browsers when they visit a crafted login URL. This affects all users of Comodo Dome Firewall 2.7.0 who have the firewall's web interface accessible.
💻 Affected Systems
- Comodo Dome Firewall
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, perform actions as authenticated users, redirect to malicious sites, or install malware on administrator workstations.
Likely Case
Session hijacking of firewall administrators leading to unauthorized configuration changes, credential theft, or lateral movement within the network.
If Mitigated
Limited impact if firewall web interface is not internet-facing and users are trained not to click suspicious links.
🎯 Exploit Status
Exploit code is publicly available on Exploit-DB. Attack requires user interaction (clicking malicious link).
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: 2.8.0 or later
Vendor Advisory: https://cdome.comodo.com/firewall/
Restart Required: Yes
Instructions:
1. Log into Comodo support portal. 2. Download latest version (2.8.0+). 3. Backup current configuration. 4. Install update following vendor instructions. 5. Restart firewall services.
🔧 Temporary Workarounds
Input Validation via WAF
allDeploy web application firewall rules to block XSS payloads in username parameter
# Example ModSecurity rule: SecRule ARGS:username "@detectXSS" "id:1001,phase:2,deny,status:403"
Restrict Web Interface Access
linuxLimit access to firewall management interface to trusted IP ranges only
# Example iptables rule: iptables -A INPUT -p tcp --dport 443 -s 192.168.1.0/24 -j ACCEPT
# iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Implement strict Content Security Policy headers to block inline script execution
- Deploy network segmentation to isolate firewall management interface from user networks
🔍 How to Verify
Check if Vulnerable:
Test by submitting <script>alert('XSS')</script> in username field during login and checking if script executesCheck Version:
ssh admin@firewall "show version" or check web interface footerVerify Fix Applied:
Verify version is 2.8.0+ and test XSS payload no longer executes📡 Detection & Monitoring
Log Indicators:
- POST requests to login endpoint with script tags in username parameter
- Unusual length or special characters in username field
Network Indicators:
- HTTP requests containing <script> tags in POST body to /login endpoint
- Multiple failed login attempts with unusual usernames
SIEM Query:
source="firewall_logs" AND uri_path="/login" AND (username CONTAINS "<script>" OR username CONTAINS "javascript:")