Detect Rockwell Automation Logix Controllers Insufficient Credential Protection (CVE-2021-22681) in Sumo Logic CSE
CVE-2021-22681 is an insufficient protection of credentials vulnerability (CWE-522) affecting Rockwell Automation multiple products including Logix controllers. An attacker can intercept or obtain weakly protected credentials used to authenticate with Logix controllers, enabling authentication bypass. This vulnerability is listed in CISA's Known Exploited Vulnerabilities catalog and poses critical risk in OT/ICS environments where unauthorized controller access could cause process disruption or physical damage.
MITRE ATT&CK
Sumo Detection Query
_index=ot_security OR _sourceCategory=network/ics OR _sourceCategory=firewall
| where dest_port in ("44818", "2222", "2221") or protocol matches /(?i)(EtherNet.IP|CIP)/
| where _raw matches /(?i)(logix|controllogix|compactlogix|guardlogix|rockwell)/
| parse regex "(?<src_ip>\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})" as src_ip
| parse regex "dest[_\\s]?ip[=:\\s]+(?<dest_ip>\\d{1,3}\\.\\d{1,3}\\.\\d{1,3}\\.\\d{1,3})" as dest_ip nodrop
| count as connection_count by src_ip, dest_ip, dest_port, protocol
| where connection_count > 0
| sort by connection_count descSumo Logic query detecting EtherNet/IP and CIP protocol connections targeting Rockwell Logix devices, supporting identification of CVE-2021-22681 exploitation attempts.
Data Sources
Required Tables
False Positives & Tuning
- Routine engineering workstation connections for PLC programming
- Asset discovery scans in OT environments
- SCADA system polling of Logix controllers
Other platforms for CVE-2021-22681
Testing Methodology
Validate this detection against 3 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.
- Test 1EtherNet/IP Controller Enumeration via nmap
Expected signal: Network connection events from the scanning host to port 44818 on multiple destination IPs; IDS alerts for CIP/EtherNet/IP enumeration
- Test 2CIP Session Credential Capture via Wireshark
Expected signal: Passive capture produces no active network events; detection depends on promiscuous mode detection or IDS passive analysis alerts
- Test 3RSLinx Classic Unauthorized Connection Attempt
Expected signal: Windows process creation for RSLinx.exe; network connection from non-engineering workstation to controller port 44818; controller audit log entry for unauthorized connection attempt
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