CVE-2021-22681
📋 TL;DR
This vulnerability allows unauthenticated attackers to bypass authentication mechanisms in Rockwell Automation industrial control systems. It affects multiple Logix controller families when used with vulnerable versions of Studio 5000 Logix Designer and RSLogix 5000 software. Attackers could gain unauthorized access to critical industrial control systems.
💻 Affected Systems
- Rockwell Automation Studio 5000 Logix Designer
- RSLogix 5000
- CompactLogix 1768
- CompactLogix 1769
- CompactLogix 5370
- CompactLogix 5380
- CompactLogix 5480
- ControlLogix 5550
- ControlLogix 5560
- ControlLogix 5570
- ControlLogix 5580
- DriveLogix 5560
- DriveLogix 5730
- 1794-L34
- Compact GuardLogix 5370
- Compact GuardLogix 5380
- GuardLogix 5570
- GuardLogix 5580
- SoftLogix 5800
📦 What is this software?
Factorytalk Services Platform by Rockwellautomation
Rslogix 5000 by Rockwellautomation
Studio 5000 Logix Designer by Rockwellautomation
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial control systems leading to physical damage, production shutdown, safety system manipulation, or environmental harm.
Likely Case
Unauthorized access to industrial controllers allowing configuration changes, logic manipulation, data exfiltration, or denial of service.
If Mitigated
Limited impact if systems are properly segmented, monitored, and have additional authentication layers.
🎯 Exploit Status
CVSS 9.8 indicates critical severity with low attack complexity. No public exploit code is known, but the vulnerability is straightforward to exploit.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Studio 5000 Logix Designer v32.011+, RSLogix 5000 requires upgrade to Studio 5000
Vendor Advisory: https://rockwellautomation.custhelp.com/app/answers/answer_view/a_id/1129798
Restart Required: Yes
Instructions:
1. Download and install Studio 5000 Logix Designer v32.011 or later from Rockwell Automation. 2. Update all affected controllers with new firmware. 3. Restart systems after patching. 4. Verify communication is restored.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected controllers and engineering workstations in separate network segments with strict firewall rules.
Access Control Lists
allImplement ACLs to restrict communication to only authorized engineering workstations and controllers.
🧯 If You Can't Patch
- Implement strict network segmentation and zero-trust architecture
- Deploy intrusion detection systems and monitor for unauthorized access attempts
🔍 How to Verify
Check if Vulnerable:
Check software version in Studio 5000 Logix Designer or RSLogix 5000. Versions in affected ranges are vulnerable.Check Version:
In Studio 5000: Help → About. In RSLogix 5000: Help → About RSLogix 5000.Verify Fix Applied:
Verify Studio 5000 Logix Designer is v32.011 or later. Test authentication with controllers to ensure proper verification.📡 Detection & Monitoring
Log Indicators:
- Failed authentication attempts followed by successful access
- Unauthorized IP addresses accessing controllers
- Unexpected configuration changes
Network Indicators:
- Unusual traffic patterns to controller ports
- Communication from unauthorized sources to controllers
SIEM Query:
source_ip NOT IN (authorized_ips) AND dest_port IN (controller_ports) AND protocol=tcp