CVE-2023-27396
📋 TL;DR
CVE-2023-27396 affects OMRON FINS protocol implementations, allowing attackers to intercept plaintext communications and inject arbitrary commands without authentication. This enables remote code execution and system information disclosure on affected industrial control systems. All versions of multiple SYSMAC CPU Unit series are vulnerable.
💻 Affected Systems
- SYSMAC CS-series CPU Units
- SYSMAC CJ-series CPU Units
- SYSMAC CP-series CPU Units
- SYSMAC NJ-series CPU Units
- SYSMAC NX1P-series CPU Units
- SYSMAC NX102-series CPU Units
- SYSMAC NX7 Database Connection CPU Units
📦 What is this software?
⚠️ Risk & Real-World Impact
Worst Case
Complete compromise of industrial control systems leading to production shutdown, equipment damage, or safety incidents through arbitrary command execution.
Likely Case
Unauthorized access to sensitive industrial data, manipulation of industrial processes, and potential production disruption.
If Mitigated
Limited impact if devices are isolated in properly segmented networks with strict access controls.
🎯 Exploit Status
No authentication required and protocol details are publicly documented, making exploitation straightforward for attackers with network access.
🛠️ Fix & Mitigation
✅ Official Fix
Patch Version: Not available
Vendor Advisory: https://www.ia.omron.com/product/vulnerability/OMSR-2023-003_en.pdf
Restart Required: No
Instructions:
No firmware patch available. Follow vendor workarounds including network segmentation, firewall rules, and disabling unnecessary services.
🔧 Temporary Workarounds
Network Segmentation
allIsolate affected devices in dedicated industrial control system networks with strict access controls.
Firewall Rules
allImplement firewall rules to restrict FINS protocol traffic (default port 9600) to authorized systems only.
🧯 If You Can't Patch
- Implement network segmentation to isolate affected devices from untrusted networks
- Deploy intrusion detection systems to monitor for FINS protocol anomalies and unauthorized access attempts
🔍 How to Verify
Check if Vulnerable:
Check if device model matches affected products list and verify FINS protocol is enabled on port 9600.Check Version:
Check device model and firmware version through OMRON programming software or device display.Verify Fix Applied:
Verify network segmentation is in place and firewall rules block unauthorized FINS traffic.📡 Detection & Monitoring
Log Indicators:
- Unauthorized FINS protocol connections
- Unexpected command executions on industrial controllers
- Multiple failed authentication attempts (though protocol lacks authentication)
Network Indicators:
- FINS protocol traffic from unauthorized IP addresses
- Unusual FINS command patterns
- Traffic to port 9600 from non-industrial networks
SIEM Query:
source_port:9600 OR dest_port:9600 AND (NOT src_ip IN [authorized_industrial_ips])🔗 References
- https://jvn.jp/en/ta/JVNTA91513661/
- https://jvn.jp/ta/JVNTA91513661/
- https://www.cisa.gov/uscert/ics/advisories/icsa-22-179-02
- https://www.fa.omron.co.jp/product/vulnerability/OMSR-2023-003_ja.pdf
- https://www.ia.omron.com/product/vulnerability/OMSR-2023-003_en.pdf
- https://www.us-cert.gov/ics/advisories/icsa-19-346-02
- https://www.us-cert.gov/ics/advisories/icsa-20-063-03
- https://jvn.jp/en/ta/JVNTA91513661/
- https://jvn.jp/ta/JVNTA91513661/
- https://www.cisa.gov/uscert/ics/advisories/icsa-22-179-02
- https://www.fa.omron.co.jp/product/vulnerability/OMSR-2023-003_ja.pdf
- https://www.ia.omron.com/product/vulnerability/OMSR-2023-003_en.pdf
- https://www.us-cert.gov/ics/advisories/icsa-19-346-02
- https://www.us-cert.gov/ics/advisories/icsa-20-063-03
