CVE-2025-9962: Novakon P Series Privilege Escalation

CVE-2025-9962 Overview

A critical buffer overflow vulnerability has been identified in the Novakon P series Human-Machine Interface (HMI) devices. This vulnerability allows remote attackers to gain root-level permissions on affected devices without any prior authentication, representing a severe threat to industrial control systems and operational technology environments.

Critical Impact
Unauthenticated remote attackers can achieve full root-level compromise of Novakon P series HMI devices via a network-accessible buffer overflow, potentially leading to complete control of industrial control systems.

Affected Products

Novakon P series HMI devices running firmware versions P – V2001.A.C518o2 through versions prior to P-2.0.05 Build 2026.02.06
Industrial control systems utilizing vulnerable Novakon P series HMI devices
OT/ICS environments with network-accessible Novakon HMI interfaces

Discovery Timeline

September 23, 2025 - CVE-2025-9962 published to NVD
March 31, 2026 - Last updated in NVD database

Technical Details for CVE-2025-9962

Vulnerability Analysis

This buffer overflow vulnerability (CWE-120: Buffer Copy without Checking Size of Input) exists in the Novakon P series HMI firmware. The flaw allows attackers to send specially crafted network requests that overflow an internal buffer, ultimately enabling arbitrary code execution with root privileges. The vulnerability is particularly dangerous because it requires no authentication, meaning any attacker with network access to the device can exploit it.

The attack can be launched remotely over the network with low complexity, requiring no user interaction or special privileges. Successful exploitation grants complete control over the affected HMI device, including the ability to read and modify sensitive data, disrupt operations, and potentially pivot to other connected industrial systems.

Root Cause

The vulnerability stems from improper input validation where the affected firmware fails to adequately check the size of user-supplied input before copying it into a fixed-size buffer. This classic buffer overflow condition (CWE-120) occurs when data written to a buffer exceeds its allocated size, corrupting adjacent memory and potentially overwriting critical program control structures such as return addresses or function pointers.

Attack Vector

The attack vector is network-based, requiring an attacker to send specially crafted requests to the vulnerable HMI device. The exploitation process involves:

Identifying a network-accessible Novakon P series HMI device
Sending a malformed request containing oversized input data designed to overflow the vulnerable buffer
Overwriting memory structures to redirect program execution
Achieving arbitrary code execution with root privileges on the embedded device

Since no authentication is required, any attacker who can reach the device over the network can attempt exploitation. In industrial environments where HMI devices may be improperly segmented from corporate networks or the internet, this significantly increases the attack surface.

For technical details on the exploitation mechanism, refer to the CyberDanube Vulnerability Research and the Novakon Security Advisory.

Detection Methods for CVE-2025-9962

Indicators of Compromise

Unusual network traffic patterns targeting Novakon HMI devices, particularly oversized requests
Unexpected process execution or system calls originating from the HMI device
Modified system files or unauthorized configuration changes on P series devices
Anomalous outbound network connections from HMI devices to unknown external hosts

Detection Strategies

Implement network intrusion detection rules to identify buffer overflow attack patterns targeting HMI interfaces
Monitor for anomalous authentication-less administrative actions on Novakon devices
Deploy honeypots mimicking Novakon P series devices to detect reconnaissance and exploitation attempts
Enable verbose logging on network security devices monitoring OT/ICS segments

Monitoring Recommendations

Establish baseline network behavior for all Novakon HMI devices and alert on deviations
Monitor firmware integrity on P series devices using host-based integrity monitoring solutions
Implement continuous vulnerability scanning for OT/ICS environments to identify unpatched devices
Review logs for failed or malformed requests that may indicate exploitation attempts

How to Mitigate CVE-2025-9962

Immediate Actions Required

Upgrade Novakon P series firmware to version P-2.0.05 Build 2026.02.06 (commit d0f97fd9) or later immediately
Isolate vulnerable HMI devices behind firewalls and restrict network access to authorized personnel only
Implement network segmentation to prevent direct access to HMI devices from untrusted networks
Audit all Novakon P series devices in your environment to identify vulnerable firmware versions

Patch Information

Novakon has released firmware version P-2.0.05 Build 2026.02.06 (commit d0f97fd9) which addresses this buffer overflow vulnerability. Organizations should review the official Novakon Firmware Update Advisory and the Novakon Security Advisory CVE-2025-9962-9966 for detailed patching instructions and download links.

Workarounds

Implement strict network access controls using firewalls to limit connectivity to HMI devices
Enable VPN requirements for remote access to industrial control networks containing vulnerable devices
Deploy web application firewalls or ICS-aware security appliances capable of filtering malicious requests
Disable unnecessary network services on HMI devices to reduce the attack surface

bash

# Example firewall rule to restrict access to Novakon HMI devices
# Allow only trusted management network to access HMI
iptables -A INPUT -s 10.10.10.0/24 -d <HMI_IP> -j ACCEPT
iptables -A INPUT -d <HMI_IP> -j DROP