CVE-2018-11711
📋 TL;DR
This vulnerability allows remote attackers to bypass authentication on Canon MF210 and MF220 multifunction printers by accessing /portal_top.html without knowing the System Manager PIN. Attackers gain full administrative control of affected devices. Only devices with default settings are vulnerable according to the vendor.
💻 Affected Systems
- Canon MF210 Series
- Canon MF220 Series
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full device compromise allowing attackers to intercept print jobs, modify device settings, install malicious firmware, or use the device as a network pivot point.
Likely Case
Unauthorized access to device configuration, potential data exfiltration from scanned documents or print jobs, and device misuse.
If Mitigated
No impact if proper security configurations are implemented as recommended in vendor documentation.
🎯 Exploit Status
Simple HTTP request to /portal_top.html bypasses authentication. Multiple public exploit scripts available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: N/A
Restart Required: No
Instructions:
No official patch. Follow vendor's security best practices: 1. Change default System Manager PIN 2. Configure proper authentication settings 3. Restrict network access to web interface
🔧 Temporary Workarounds
Change Default Authentication Settings
allConfigure strong System Manager PIN and enable proper authentication mechanisms
Access device web interface > System Settings > Security > Change System Manager PIN
Network Segmentation
linuxRestrict access to printer web interface using firewall rules
iptables -A INPUT -p tcp --dport 80 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 443 -s trusted_network -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
iptables -A INPUT -p tcp --dport 443 -j DROP
🧯 If You Can't Patch
- Disable web interface entirely if not needed for operations
- Place printers on isolated VLAN with strict access controls
🔍 How to Verify
Check if Vulnerable:
Attempt to access http://[printer-ip]/portal_top.html without authentication. If you gain access to administrative functions, device is vulnerable.Check Version:
Check device information page in web interface or printed configuration pageVerify Fix Applied:
Verify that accessing /portal_top.html without proper authentication returns an error or redirects to login page.📡 Detection & Monitoring
Log Indicators:
- Unauthorized access attempts to /portal_top.html
- Multiple failed login attempts followed by successful /portal_top.html access
- Administrative configuration changes from unexpected IP addresses
Network Indicators:
- HTTP GET requests to /portal_top.html without preceding successful authentication
- Unusual administrative traffic patterns to printer interfaces
SIEM Query:
source="printer_logs" AND (url="/portal_top.html" OR (event="auth_failure" AND subsequent_event="admin_access"))