CVE-2021-40422
📋 TL;DR
CVE-2021-40422 is an authentication bypass vulnerability in Swift Sensors Gateway SG3-1010 that allows remote attackers to execute arbitrary code without authentication. This affects organizations using the vulnerable gateway device for sensor data collection and management. Attackers can exploit this by sending specially crafted network requests to bypass authentication mechanisms.
💻 Affected Systems
- Swift Sensors Gateway SG3-1010
📦 What is this software?
Sg3 1010 Firmware by Swiftsensors
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of the gateway device leading to full network access, data exfiltration, and potential lateral movement to connected sensor networks and industrial control systems.
Likely Case
Remote code execution allowing attackers to install malware, disrupt sensor operations, and gain persistent access to the gateway for further attacks.
If Mitigated
Limited impact with proper network segmentation and access controls preventing exploitation attempts from reaching vulnerable devices.
🎯 Exploit Status
Detailed exploit information and proof-of-concept code are publicly available in the Talos Intelligence reports.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Check with Swift Sensors for specific patched firmware version
Vendor Advisory: https://talosintelligence.com/vulnerability_reports/TALOS-2021-1431
Restart Required: Yes
Instructions:
1. Contact Swift Sensors support for patched firmware
2. Backup current configuration
3. Upload and install patched firmware via web interface
4. Reboot device
5. Verify firmware version and functionality
🔧 Temporary Workarounds
Network Isolation
linuxIsolate the gateway device from untrusted networks and restrict access to management interfaces
iptables -A INPUT -s <trusted_networks> -p tcp --dport 80,443 -j ACCEPT
iptables -A INPUT -p tcp --dport 80,443 -j DROP
Access Control Lists
allImplement strict network access controls to limit connections to the gateway
access-list 101 permit tcp <trusted_hosts> host <gateway_ip> eq 80
access-list 101 permit tcp <trusted_hosts> host <gateway_ip> eq 443
access-list 101 deny ip any any
🧯 If You Can't Patch
- Immediately isolate the device from all untrusted networks including internet access
- Implement strict firewall rules allowing only necessary traffic from authorized management stations
🔍 How to Verify
Check if Vulnerable:
Check firmware version against vendor advisory and test for authentication bypass using documented exploit patternsCheck Version:
Check web interface admin panel or use curl -k https://<gateway_ip>/versionVerify Fix Applied:
Verify patched firmware version is installed and test that authentication bypass attempts are properly rejected📡 Detection & Monitoring
Log Indicators:
- Multiple failed authentication attempts followed by successful access
- Unusual process execution or system command patterns
- Authentication bypass patterns in web server logs
Network Indicators:
- Unusual HTTP requests to authentication endpoints
- Rapid sequence of requests to password generation functionality
- Traffic from unexpected sources to gateway management ports
SIEM Query:
source="gateway_logs" AND (http_uri="*/auth*" OR http_uri="*/password*" OR http_status=200) AND src_ip NOT IN [trusted_management_ips]