CVE-2025-1924: Yokogawa Vnet/IP Interface RCE Vulnerability

CVE-2025-1924 Overview

A vulnerability has been discovered in the Vnet/IP Interface Package provided by Yokogawa Electric Corporation. This integer underflow vulnerability (CWE-191) affects critical industrial control system components used in CENTUM VP distributed control systems. If affected products receive maliciously crafted packets, a Denial of Service (DoS) attack may cause Vnet/IP communication functions to stop, or arbitrary programs may be executed.

This vulnerability poses significant risk to industrial environments where Yokogawa CENTUM VP systems are deployed for process automation and control operations. The attack requires adjacent network access, making it particularly concerning in environments where network segmentation may be inadequate.

Critical Impact

Maliciously crafted network packets can cause Vnet/IP communication to stop functioning or enable arbitrary code execution in industrial control systems.

Affected Products

• Vnet/IP Interface Package for CENTUM VP R6 (VP6C3300) - Version R1.07.00 or earlier
• Vnet/IP Interface Package for CENTUM VP R7 (VP7C3300) - Version R1.07.00 or earlier

Discovery Timeline

• 2026-02-13 - CVE-2025-1924 published to NVD
• 2026-02-13 - Last updated in NVD database

Technical Details for CVE-2025-1924

Vulnerability Analysis

This vulnerability stems from an integer underflow condition (CWE-191) in the Vnet/IP Interface Package. Integer underflow occurs when an arithmetic operation attempts to create a numeric value that falls below the minimum value the data type can represent, causing the value to wrap around to a large positive number or result in unexpected behavior.

In the context of industrial control systems like CENTUM VP, the Vnet/IP Interface Package handles network communications between process control components. The vulnerability can be exploited by an attacker on an adjacent network who sends specially crafted packets to the vulnerable interface. The attack complexity is high, but requires no privileges or user interaction to execute.

Successful exploitation can result in two primary outcomes: disruption of Vnet/IP communication functions (Denial of Service), or in certain conditions, execution of arbitrary programs. For industrial control systems, even a temporary loss of communication could have serious operational consequences.

Root Cause

The root cause is an integer underflow condition (CWE-191) in the packet processing logic of the Vnet/IP Interface Package. When processing certain network packets, the software performs arithmetic operations on integer values without adequate boundary checking. This allows specially crafted input to trigger an underflow condition, causing unexpected behavior in memory operations or control flow.

Attack Vector

The attack vector requires adjacent network access (AV:A), meaning an attacker must have access to the same network segment as the vulnerable Yokogawa system. While the attack complexity is high (AC:H), successful exploitation requires no privileges (PR:N) and no user interaction (UI:N).

An attacker would craft malicious network packets designed to trigger the integer underflow condition in the Vnet/IP communication handler. When processed by the vulnerable component, these packets can cause the communication functions to crash or potentially allow execution of attacker-controlled code.

The vulnerability affects the integrity and availability of both the vulnerable system and potentially connected systems in the industrial control environment.

Detection Methods for CVE-2025-1924

Indicators of Compromise

• Unexpected termination or restart of Vnet/IP communication services
• Anomalous network traffic patterns targeting CENTUM VP systems on the local network segment
• Log entries indicating packet processing errors or memory corruption in Vnet/IP components
• Unexplained loss of communication between CENTUM VP controllers and interface packages

Detection Strategies

• Implement network intrusion detection systems (IDS) to monitor for malformed packets targeting Yokogawa industrial control protocols
• Monitor Vnet/IP Interface Package processes for unexpected crashes, restarts, or abnormal memory usage
• Deploy SentinelOne agents on engineering workstations and HMI systems to detect anomalous behavior patterns
• Review system logs for evidence of exploitation attempts or communication failures

Monitoring Recommendations

• Enable detailed logging on CENTUM VP systems and forward logs to a centralized SIEM for correlation
• Monitor network traffic on segments containing Yokogawa control systems for unusual patterns
• Establish baseline behavior for Vnet/IP communication and alert on deviations
• Configure alerts for service interruptions affecting Vnet/IP communication functions

How to Mitigate CVE-2025-1924

Immediate Actions Required

• Review the Yokogawa Security Advisory YSAR-26-0002 for vendor-specific guidance
• Inventory all affected CENTUM VP R6 and R7 systems with Vnet/IP Interface Package version R1.07.00 or earlier
• Implement network segmentation to restrict access to adjacent networks where vulnerable systems reside
• Apply any available patches from Yokogawa following proper change management procedures

Patch Information

Organizations should consult the official Yokogawa Security Advisory YSAR-26-0002 for specific patch information and remediation guidance. Contact Yokogawa support for assistance with obtaining and applying security updates to affected Vnet/IP Interface Package installations.

Ensure all patches are tested in a non-production environment before deployment to production industrial control systems to verify compatibility and stability.

Workarounds

• Implement strict network segmentation to isolate CENTUM VP systems from untrusted network segments
• Deploy firewall rules to restrict traffic to the Vnet/IP Interface Package from authorized systems only
• Enable network monitoring and anomaly detection on segments containing affected systems
• Consider implementing application-layer firewalls or deep packet inspection for industrial protocols where feasible

# Network segmentation example - restrict access to CENTUM VP systems
# Implement firewall rules to limit adjacent network access
iptables -A INPUT -i eth0 -s 10.0.0.0/24 -p tcp --dport <vnet_port> -j ACCEPT
iptables -A INPUT -i eth0 -p tcp --dport <vnet_port> -j DROP
# Replace <vnet_port> with actual Vnet/IP port numbers
# Consult Yokogawa documentation for specific port requirements