CVE-2025-7693 Overview
A critical input validation vulnerability exists in industrial control systems due to improper handling of malformed CIP (Common Industrial Protocol) Forward Close packets. When an attacker sends specially crafted CIP Forward Close packets to a vulnerable controller, the device enters a solid red Fault LED state and becomes completely unresponsive. Upon power cycling, the controller enters a recoverable fault state where the MS LED and Fault LED flash red, reporting fault code 0xF015. This vulnerability was discovered during fuzzing operations and can be exploited remotely without authentication.
Critical Impact
Remote attackers can cause industrial controllers to crash and become unresponsive, potentially disrupting critical industrial processes. Recovery requires physical intervention to power cycle the device and clear the fault state.
Affected Products
- Rockwell Automation Industrial Controllers (See Rockwell Automation Security Advisory for specific affected models)
Discovery Timeline
- 2025-08-18 - CVE-2025-7693 published to NVD
- 2025-08-18 - Last updated in NVD database
Technical Details for CVE-2025-7693
Vulnerability Analysis
This vulnerability is classified under CWE-20 (Improper Input Validation), indicating that the affected controllers fail to properly validate input data contained within CIP Forward Close packets before processing them. The Common Industrial Protocol (CIP) is widely used in industrial automation environments for communication between devices, making this a significant concern for operational technology (OT) environments.
The vulnerability was identified through fuzz testing, where malformed packets were systematically generated and sent to the target device to identify edge cases that cause unexpected behavior. In this instance, specific malformed CIP Forward Close packets trigger a fault condition that renders the controller inoperable.
The network-accessible nature of this vulnerability means that any attacker with network connectivity to the affected controller can exploit it without requiring authentication or user interaction, making it particularly dangerous in environments where industrial control systems are exposed to untrusted networks.
Root Cause
The root cause is improper input validation when processing CIP Forward Close packets. The controller does not adequately sanitize or validate the structure and contents of incoming packets, allowing malformed data to trigger an unhandled exception or fault condition. This causes the controller firmware to enter an error state, activating the Fault LED and halting normal operations.
Attack Vector
The attack is network-based and requires no authentication or user interaction. An attacker can remotely send malformed CIP Forward Close packets to a vulnerable controller over the network. The CIP protocol typically operates over TCP/UDP port 44818 (EtherNet/IP), making it accessible to any host with network connectivity to the controller.
The exploitation process involves:
- Identifying a vulnerable controller on the network
- Crafting malformed CIP Forward Close packets with invalid or unexpected field values
- Sending the malicious packets to the target controller
- The controller enters a fault state, becoming unresponsive
- Physical intervention is required to power cycle and clear the fault
No verified proof-of-concept code is publicly available. The vulnerability can be triggered by sending malformed CIP Forward Close packets to the target controller. See the Rockwell Automation Security Advisory for additional technical details.
Detection Methods for CVE-2025-7693
Indicators of Compromise
- Controller enters solid red Fault LED state unexpectedly
- Controller becomes unresponsive to normal commands and communications
- After power cycle, MS LED and Fault LED flash red
- Fault code 0xF015 reported in controller diagnostics
- Unusual or malformed CIP traffic observed on the network targeting port 44818
Detection Strategies
- Monitor network traffic for anomalous CIP Forward Close packets with malformed structures
- Implement intrusion detection signatures for malformed CIP protocol traffic
- Deploy SentinelOne Singularity for OT to detect and alert on suspicious network activity targeting industrial control systems
- Configure network monitoring to alert on unexpected controller fault conditions
Monitoring Recommendations
- Enable logging of CIP protocol communications at network boundaries
- Monitor controller health status and fault indicators through SCADA/HMI systems
- Implement network segmentation monitoring to detect unauthorized access to controller networks
- Review network traffic logs for repeated connection attempts to CIP-enabled devices from unusual sources
How to Mitigate CVE-2025-7693
Immediate Actions Required
- Isolate affected controllers from untrusted networks immediately
- Implement network segmentation to restrict access to industrial control networks
- Deploy firewalls or access control lists to limit CIP traffic to authorized hosts only
- Review and restrict access to TCP/UDP port 44818 (EtherNet/IP)
- Monitor for signs of exploitation including unexpected controller faults
Patch Information
Rockwell Automation has published a security advisory addressing this vulnerability. Refer to the Rockwell Automation Security Advisory SD1736 for specific patch information, affected product versions, and firmware updates to remediate this vulnerability.
Workarounds
- Implement strict network segmentation to isolate industrial controllers from corporate and external networks
- Deploy application-layer firewalls capable of inspecting and filtering CIP protocol traffic
- Restrict network access to controllers using allowlists of authorized IP addresses
- Monitor for and alert on fault code 0xF015 to quickly identify exploitation attempts
- Establish recovery procedures to minimize downtime when power cycling affected controllers
# Example firewall rule to restrict CIP traffic (adjust for your environment)
# Allow CIP traffic only from authorized SCADA/HMI hosts
iptables -A INPUT -p tcp --dport 44818 -s 10.0.1.100 -j ACCEPT
iptables -A INPUT -p tcp --dport 44818 -s 10.0.1.101 -j ACCEPT
iptables -A INPUT -p tcp --dport 44818 -j DROP
iptables -A INPUT -p udp --dport 44818 -s 10.0.1.100 -j ACCEPT
iptables -A INPUT -p udp --dport 44818 -s 10.0.1.101 -j ACCEPT
iptables -A INPUT -p udp --dport 44818 -j DROP
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
