CVE-2021-41296
📋 TL;DR
ECOA BAS controllers use weak default administrative credentials that can be easily guessed in remote password attacks, allowing attackers to gain full control of the system. This affects all systems running vulnerable ECOA BAS controller software with default credentials unchanged.
💻 Affected Systems
- ECOA BAS controllers
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Attackers gain full administrative control of building automation systems, potentially manipulating HVAC, lighting, security systems, or using the controller as an entry point to other networked systems.
Likely Case
Attackers compromise the controller to disrupt building operations, steal sensitive building data, or use the system as a pivot point for further network attacks.
If Mitigated
Systems with strong unique passwords experience no impact as the vulnerability requires weak/default credentials to be exploitable.
🎯 Exploit Status
Exploitation requires only password guessing/brute-forcing of known default credentials.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: N/A
Vendor Advisory: https://www.twcert.org.tw/tw/cp-132-5132-65705-1.html
Restart Required: No
Instructions:
1. Change all default administrative passwords to strong, unique passwords. 2. Implement account lockout policies if supported. 3. Disable unnecessary administrative accounts.
🔧 Temporary Workarounds
Password Policy Enforcement
allImplement strong password policies and change all default credentials
Network Segmentation
allIsolate BAS controllers from general network and internet access
🧯 If You Can't Patch
- Implement network access controls to restrict access to BAS controllers
- Monitor authentication logs for brute force attempts and failed logins
🔍 How to Verify
Check if Vulnerable:
Check if administrative accounts still use default credentials by attempting login with known defaults or reviewing configuration.Check Version:
Check controller web interface or management console for version information.Verify Fix Applied:
Verify that default credentials no longer work and strong passwords are required for all administrative accounts.📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts
- Successful logins from unusual IP addresses
- Authentication with default usernames
Network Indicators:
- Brute force attempts on administrative ports
- Unexpected administrative access from external networks
SIEM Query:
source="bas_controller" AND (event_type="authentication_failure" OR user="admin" OR user="administrator")