CVE-2022-1797: Rockwell CompactLogix 5380 DoS Vulnerability

CVE-2022-1797 Overview

A denial-of-service vulnerability exists in Rockwell Automation Logix Controllers that can be exploited through malformed Class 3 Common Industrial Protocol (CIP) messages. When an attacker sends a specially crafted CIP message over a cached connection, it triggers a major nonrecoverable fault in the affected controller, causing the device to become unavailable. Recovery requires manual intervention to clear the fault and redownload the user project file to restore normal operations.

This vulnerability affects industrial control systems (ICS) environments where Rockwell Automation Logix Controllers are deployed, making it particularly concerning for critical infrastructure and manufacturing operations.

Critical Impact

Exploitation results in complete denial-of-service with manual recovery required, potentially disrupting critical industrial processes and manufacturing operations.

Affected Products

• Rockwell Automation CompactLogix 5380 (all firmware versions)
• Rockwell Automation Compact GuardLogix 5380 (all firmware versions)
• Rockwell Automation CompactLogix 5480 (all firmware versions)
• Rockwell Automation ControlLogix 5580 (all firmware versions)
• Rockwell Automation GuardLogix 5580 (all firmware versions)
• Rockwell Automation CompactLogix 5370 (all firmware versions)
• Rockwell Automation Compact GuardLogix 5370 (all firmware versions)
• Rockwell Automation ControlLogix 5570 (all firmware versions)
• Rockwell Automation GuardLogix 5570 (all firmware versions)

Discovery Timeline

• June 2, 2022 - CVE-2022-1797 published to NVD
• November 21, 2024 - Last updated in NVD database

Technical Details for CVE-2022-1797

Vulnerability Analysis

This vulnerability is classified under CWE-400 (Uncontrolled Resource Consumption), indicating that the affected Logix Controllers fail to properly handle malformed Class 3 CIP messages when received over a cached connection. The CIP protocol is a widely used application layer protocol in industrial automation environments, making this vulnerability particularly relevant to operational technology (OT) security.

The attack can be executed remotely over a network without requiring authentication or user interaction. When exploited, the controller enters a major nonrecoverable fault state, completely halting its operations. Unlike typical denial-of-service conditions that may resolve automatically, this vulnerability requires physical or remote administrative access to clear the fault and restore the user project, extending downtime significantly.

The scope of impact extends beyond the vulnerable component itself, as dependent systems and processes relying on the controller will also be affected by the outage.

Root Cause

The root cause lies in improper handling of malformed Class 3 CIP messages within the controller's communication processing logic. When the controller receives a specially crafted message over an already established (cached) connection, it fails to properly validate or sanitize the message content before processing, leading to uncontrolled resource consumption that triggers a fatal fault condition.

Attack Vector

The attack is network-based and can be executed remotely by an attacker with network access to the affected controller. The attacker must be able to establish a Class 3 CIP connection with the target device. Once a connection is cached, sending a malformed CIP message causes the controller to enter a major nonrecoverable fault state.

The attack flow involves:

1. Establishing a Class 3 CIP connection to the target Logix Controller
2. Allowing the connection to be cached by the controller
3. Sending a malformed CIP message over the established connection
4. The controller fails to handle the malformed message properly
5. A major nonrecoverable fault is triggered, taking the controller offline

No proof-of-concept exploit code is publicly available for this vulnerability. The malformed message exploits weaknesses in the CIP message parsing logic, causing resource exhaustion or exception handling failures that result in the fault condition.

Detection Methods for CVE-2022-1797

Indicators of Compromise

• Unexpected major nonrecoverable faults on Logix Controllers without apparent cause
• Controllers requiring manual fault clearing and project redownload to recover
• Anomalous CIP traffic patterns targeting affected controller models
• Multiple controller failures occurring in rapid succession across the network

Detection Strategies

• Monitor CIP traffic for malformed Class 3 messages using network intrusion detection systems (NIDS) with OT-specific rulesets
• Implement anomaly detection for unusual CIP connection patterns or message structures
• Deploy industrial protocol-aware security monitoring tools that can inspect CIP traffic content
• Configure SIEM alerts for multiple controller fault events within a short timeframe

Monitoring Recommendations

• Enable controller event logging and forward logs to a centralized security monitoring platform
• Monitor network traffic on EtherNet/IP ports (TCP/UDP 44818) for suspicious activity
• Implement baseline monitoring for normal CIP communication patterns to detect deviations
• Review controller fault logs regularly for signs of exploitation attempts

How to Mitigate CVE-2022-1797

Immediate Actions Required

• Review the Rockwell Automation Security Advisory for vendor-specific guidance
• Implement network segmentation to isolate Logix Controllers from untrusted networks
• Restrict network access to controllers using firewalls and access control lists (ACLs)
• Review the CISA ICS Advisory ICSA-22-144-01 for additional mitigation recommendations

Patch Information

Rockwell Automation has released guidance and mitigations for this vulnerability. Organizations should consult the Rockwell Automation Security Advisory for specific firmware updates and patch availability for their affected controller models. Contact Rockwell Automation support for access to the latest firmware versions that address this vulnerability.

Workarounds

• Implement strict network segmentation to limit CIP protocol access to authorized systems only
• Use VPNs or encrypted tunnels for remote access to industrial control networks
• Disable unused CIP connections and services where possible
• Deploy industrial firewalls with deep packet inspection (DPI) capabilities for CIP traffic
• Maintain offline backups of controller project files to expedite recovery if exploitation occurs

# Example firewall rule to restrict CIP access (adapt to your environment)
# Allow CIP traffic only from authorized engineering workstations
iptables -A INPUT -p tcp --dport 44818 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p udp --dport 44818 -s 192.168.10.0/24 -j ACCEPT
iptables -A INPUT -p tcp --dport 44818 -j DROP
iptables -A INPUT -p udp --dport 44818 -j DROP