CVE-2019-7266
📋 TL;DR
CVE-2019-7266 is an authentication bypass vulnerability in Linear eMerge 50P/5000P access control systems. Attackers can bypass authentication mechanisms to gain unauthorized access, potentially leading to remote code execution. This affects organizations using these physical security devices for building access control.
💻 Affected Systems
- Linear eMerge 50P
- Linear eMerge 5000P
📦 What is this software?
Linear Emerge 5000p Firmware by Nortekcontrol
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of physical security systems allowing attackers to unlock doors, disable alarms, execute arbitrary code on devices, and pivot to internal networks.
Likely Case
Unauthorized access to building areas, manipulation of access logs, and potential installation of backdoors on vulnerable devices.
If Mitigated
Limited impact if devices are isolated on separate VLANs with strict network segmentation and monitored for anomalous authentication attempts.
🎯 Exploit Status
Public exploit code is available that allows remote code execution without authentication. The vulnerability is actively exploited in the wild.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Version 4.6.08 and later
Vendor Advisory: https://www.applied-risk.com/resources/ar-2019-006
Restart Required: Yes
Instructions:
1. Download firmware version 4.6.08 or later from Linear/Nortek Control. 2. Backup current configuration. 3. Upload new firmware via web interface. 4. Reboot device. 5. Verify firmware version after reboot.
🔧 Temporary Workarounds
Network Segmentation
allIsolate eMerge devices on separate VLAN with strict firewall rules limiting access to management interfaces.
Access Control Lists
linuxImplement IP-based access restrictions to only allow management from authorized administrative networks.
iptables -A INPUT -p tcp --dport 80 -s 192.168.1.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 80 -j DROP
🧯 If You Can't Patch
- Disable remote web interface access and require physical console access for management
- Implement network monitoring and intrusion detection specifically for authentication bypass attempts on these devices
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface at http://device-ip/status or via SSH if enabled. Versions 4.6.07 and below are vulnerable.Check Version:
curl -s http://device-ip/status | grep -i versionVerify Fix Applied:
Verify firmware version shows 4.6.08 or higher. Test authentication bypass attempts should fail.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful access without valid credentials
- Unusual HTTP requests to authentication endpoints
- Multiple login attempts from single IP in short timeframe
Network Indicators:
- HTTP requests to /card_scan_decoder.php or other authentication bypass endpoints
- Unusual outbound connections from eMerge devices
- Traffic to known exploit IPs
SIEM Query:
source="eMerge" AND (event_type="auth_failure" OR event_type="auth_success") | stats count by src_ip, user🔗 References
- http://packetstormsecurity.com/files/155250/Linear-eMerge50P-5000P-4.6.07-Remote-Code-Execution.html
- https://applied-risk.com/labs/advisories
- https://www.applied-risk.com/resources/ar-2019-006
- https://www.us-cert.gov/ics/advisories/icsa-20-184-01
- http://packetstormsecurity.com/files/155250/Linear-eMerge50P-5000P-4.6.07-Remote-Code-Execution.html
- https://applied-risk.com/labs/advisories
- https://www.applied-risk.com/resources/ar-2019-006
- https://www.us-cert.gov/ics/advisories/icsa-20-184-01
