CVE-2018-11692
📋 TL;DR
This vulnerability allows attackers to bypass administrator authentication on affected Canon printers by exploiting a flaw in the web interface. Attackers can gain administrative access without credentials when devices use default settings. This affects Canon LBP6650, LBP3370, LBP3460, and LBP7750C printer models.
💻 Affected Systems
- Canon LBP6650
- Canon LBP3370
- Canon LBP3460
- Canon LBP7750C
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Full administrative control of printer devices, enabling configuration changes, firmware manipulation, data interception, and potential use as network pivot points.
Likely Case
Unauthorized access to printer settings, potential data exposure from print jobs, and device configuration tampering.
If Mitigated
Minimal impact if authentication is properly configured and default settings are changed per vendor recommendations.
🎯 Exploit Status
Exploit involves accessing /frame.cgi?page=DevStatus to bypass /tlogin.cgi authentication. Public exploit code available.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: N/A
Restart Required: No
Instructions:
No official patch. Follow vendor documentation for countermeasures: 1. Change default administrator credentials 2. Implement network segmentation 3. Apply security best practices from Canon documentation
🔧 Temporary Workarounds
Change Default Credentials
allChange default administrator password and implement strong authentication
Access printer web interface > Administration > Security > Change Administrator Password
Network Segmentation
linuxIsolate printers on separate VLAN with restricted access
# Example firewall rule to restrict printer management interface
# iptables -A INPUT -p tcp --dport 80 -s trusted_network -j ACCEPT
# iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Implement network access controls to restrict access to printer management interfaces (ports 80/443)
- Disable web management interface if not required, use local console for configuration
🔍 How to Verify
Check if Vulnerable:
Attempt to access /frame.cgi?page=DevStatus on printer web interface, then try to access /tlogin.cgi without authentication. If successful, device is vulnerable.Check Version:
Access printer web interface > About or System Information to check firmware versionVerify Fix Applied:
Verify strong administrator password is set and cannot be bypassed using the exploit method. Test authentication bypass attempts fail.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful access to /tlogin.cgi
- Access to /frame.cgi?page=DevStatus from unauthorized IPs
Network Indicators:
- HTTP requests to /frame.cgi?page=DevStatus followed by /tlogin.cgi access
- Unusual administrative configuration changes
SIEM Query:
source="printer_logs" AND (uri="/frame.cgi?page=DevStatus" OR uri="/tlogin.cgi") AND response_code=200