CVE-2019-25398
📋 TL;DR
This CVE describes multiple cross-site scripting vulnerabilities in IPFire's ovpnmain.cgi script that allow attackers to inject malicious JavaScript through VPN configuration parameters. When exploited, attackers can execute arbitrary scripts in administrator browsers, potentially compromising the firewall management interface. This affects IPFire administrators who manage VPN configurations through the web interface.
💻 Affected Systems
- IPFire
📦 What is this software?
Ipfire by Ipfire
⚠️ Risk & Real-World Impact
Worst Case
Attackers could steal administrator session cookies, perform actions as the administrator, install backdoors, or pivot to internal networks from the compromised firewall management interface.
Likely Case
Attackers would steal administrator credentials or session tokens to gain unauthorized access to the firewall management console, potentially modifying firewall rules or VPN configurations.
If Mitigated
With proper input validation and output encoding, the malicious scripts would be rendered harmless as text rather than executed code.
🎯 Exploit Status
Exploitation requires the attacker to trick an administrator into visiting a malicious link or submitting a specially crafted form, but the exploit code is publicly available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: IPFire 2.21 Core Update 128 or later
Vendor Advisory: https://www.ipfire.org/news
Restart Required: Yes
Instructions:
1. Log into IPFire web interface as admin. 2. Navigate to System > Updates. 3. Apply all available updates. 4. Reboot the firewall after updates complete.
🔧 Temporary Workarounds
Input Validation Filter
linuxAdd input validation to reject or sanitize script tags and JavaScript in VPN configuration parameters
# Requires modifying ovpnmain.cgi script to sanitize inputs
Access Restriction
linuxRestrict access to the firewall management interface to trusted IP addresses only
# Add to /etc/sysconfig/firewall.local: ACCEPT TCP 444 FROM trusted_ip TO any PORT 444
# Then restart firewall: /etc/init.d/firewall restart
🧯 If You Can't Patch
- Implement strict Content Security Policy headers to prevent script execution
- Use browser extensions that block XSS attacks on the administrator workstation
🔍 How to Verify
Check if Vulnerable:
Check if running IPFire 2.21 Core Update 127 by examining /var/ipfire/main/version fileCheck Version:
cat /var/ipfire/main/versionVerify Fix Applied:
Verify version is 2.21 Core Update 128 or later and test XSS payloads in VPN configuration fields return sanitized output📡 Detection & Monitoring
Log Indicators:
- POST requests to /cgi-bin/ovpnmain.cgi with script tags or JavaScript in parameters
- Unusual VPN configuration changes from unexpected sources
Network Indicators:
- HTTP requests containing <script> tags or JavaScript in POST parameters to firewall management interface
SIEM Query:
source="ipfire" AND (url="*ovpnmain.cgi*" AND (param="*<script>*" OR param="*javascript:*" OR param="*onload=*"))