CVE-2020-6974
📋 TL;DR
CVE-2020-6974 is a critical path traversal vulnerability in Honeywell Notifier Web Server (NWS) that allows attackers to access restricted directories and files. This affects organizations using Honeywell fire alarm and emergency communication systems with vulnerable NWS firmware. Attackers can potentially read sensitive configuration files or upload malicious content.
💻 Affected Systems
- Honeywell Notifier Web Server (NWS)
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete system compromise allowing attackers to modify fire alarm configurations, disable emergency notifications, or install persistent backdoors on critical safety systems.
Likely Case
Unauthorized access to sensitive system files, configuration data exposure, and potential for further lateral movement within the network.
If Mitigated
Limited impact with proper network segmentation and access controls preventing external access to the vulnerable interface.
🎯 Exploit Status
Path traversal vulnerabilities are typically easy to exploit with basic web security testing tools.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Firmware update beyond Version 3.50
Vendor Advisory: https://www.us-cert.gov/ics/advisories/icsa-20-051-03
Restart Required: Yes
Instructions:
1. Download latest firmware from Honeywell support portal. 2. Backup current configuration. 3. Apply firmware update via web interface or local console. 4. Reboot system. 5. Verify version update.
🔧 Temporary Workarounds
Network Segmentation
allIsolate NWS systems from untrusted networks and restrict access to management interfaces.
Access Control Lists
allImplement strict firewall rules limiting access to NWS web interface to authorized IP addresses only.
🧯 If You Can't Patch
- Implement network segmentation to isolate NWS from other critical systems
- Deploy web application firewall (WAF) with path traversal protection rules
🔍 How to Verify
Check if Vulnerable:
Check web interface version at /version endpoint or login page footer. If version shows 3.50, system is vulnerable.Check Version:
curl -k https://[NWS_IP]/version or check web interface login pageVerify Fix Applied:
Verify firmware version is updated beyond 3.50 and test path traversal attempts return proper access denied responses.📡 Detection & Monitoring
Log Indicators:
- Multiple 403/404 errors with directory traversal patterns (../, ..\)
- Unusual file access attempts outside normal web directories
Network Indicators:
- HTTP requests containing ../ patterns
- Unusual file extensions or paths in web requests
SIEM Query:
web.url:*../* AND (dst.port:80 OR dst.port:443) AND dst.ip:[NWS_IP_RANGE]