CVE-2019-7264
📋 TL;DR
CVE-2019-7264 is a critical stack-based buffer overflow vulnerability in Linear eMerge E3-Series access control devices running on ARM platforms. This allows remote attackers to execute arbitrary code with root privileges, potentially taking full control of the physical security system. Organizations using these access control devices for building security are affected.
💻 Affected Systems
- Linear eMerge E3-Series access control systems
📦 What is this software?
Linear Emerge Elite Firmware by Nortekcontrol
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of physical access control systems allowing attackers to unlock doors, disable alarms, manipulate access logs, and establish persistence in building networks.
Likely Case
Remote code execution leading to unauthorized access to secure areas, data exfiltration from access logs, and lateral movement into corporate networks.
If Mitigated
Limited impact if devices are isolated in separate VLANs with strict network segmentation and access controls.
🎯 Exploit Status
Exploit code is publicly available and can be executed without authentication. The vulnerability is in the web interface component.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware updates provided by Linear (now Nortek Security & Control)
Vendor Advisory: https://www.applied-risk.com/resources/ar-2019-005
Restart Required: Yes
Instructions:
1. Contact Linear/Nortek for latest firmware. 2. Backup current configuration. 3. Apply firmware update via web interface or console. 4. Reboot device. 5. Verify update and restore configuration if needed.
🔧 Temporary Workarounds
Network Segmentation
allIsolate eMerge devices in separate VLAN with strict firewall rules
Access Control Lists
linuxRestrict network access to management interfaces
iptables -A INPUT -s [TRUSTED_NETWORK] -p tcp --dport 80,443 -j ACCEPT
iptables -A INPUT -p tcp --dport 80,443 -j DROP
🧯 If You Can't Patch
- Immediately isolate devices from internet and restrict network access to management interfaces
- Implement physical security monitoring and manual access control procedures as backup
🔍 How to Verify
Check if Vulnerable:
Check firmware version via web interface at http://[device-ip]/ and compare with patched versions from vendorCheck Version:
curl -s http://[device-ip]/ | grep -i 'firmware\|version' or check web interface System Information pageVerify Fix Applied:
Verify firmware version matches patched release and test web interface functionality📡 Detection & Monitoring
Log Indicators:
- Multiple failed buffer overflow attempts in web server logs
- Unusual process execution or privilege escalation
Network Indicators:
- Unusual outbound connections from eMerge devices
- Exploit pattern traffic to port 80/443
SIEM Query:
source="eMerge" AND (event_type="buffer_overflow" OR process="privilege_escalation")