Delta CNCSoft-G2 Vulnerability: Protect Your HMI Systems Now

Delta CNCSoft-G2 Heap Overflow: Secure Your HMI Now​

Delta Electronics has issued a cybersecurity advisory related to its CNCSoft-G2 human-machine interface (HMI) system—a key component in many industrial environments. The advisory details a heap-based buffer overflow vulnerability (CVE-2025-22881) that could enable an attacker to execute code remotely under certain conditions. In this article, we break down the technical details, risk evaluation, and recommended mitigations, helping Windows users and IT professionals understand the broader implications of this issue.

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Vulnerability in a Nutshell​

What’s the Issue?
The vulnerability lies in the improper validation of user-supplied data before being copied into a fixed-length heap-based buffer. The flaw, identified as a heap-based buffer overflow (CWE-122), affects CNCSoft-G2 versions V2.1.0.10 and earlier. Although the vulnerability is not directly exploitable remotely, a successful attack could allow the execution of arbitrary code within the context of the HMI process.
Risk Ratings at a Glance:

• CVSS v4 Base Score: 8.5
• CVSS v3.1 Base Score: 7.8
• Attack Complexity: Low
• Impacted Sectors: Energy and critical manufacturing, among others
• Research Attribution: Detected by Trend Micro Zero Day Initiative and reported to CISA

This vulnerability is particularly concerning given the role of CNCSoft-G2 in critical infrastructure. Its exploitation could result in significant impacts if organizations do not apply the necessary mitigations.

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Technical Details & Security Implications​

Heap-Based Buffer Overflow Explained​

At the core of this vulnerability is a common programming mistake: failing to verify the length of input data before copying it to a fixed-size buffer. When this oversight occurs, it potentially allows an attacker to overwrite adjacent memory. In the context of Delta Electronics’ CNCSoft-G2, this can lead to remote code execution, which is especially dangerous if deployed in a critical industrial environment.

Understanding the CVSS Scores​

• CVSS v4 Score of 8.5 implies the vulnerability is severe, with a low barrier for exploitation if the attacker can persuade a user to interact with a malicious file or webpage.
• CVSS v3.1 Score of 7.8 reinforces that while the chances of exploitation might be somewhat moderated by certain factors (such as local access), the potential consequences remain grave.

For IT administrators and cybersecurity professionals, these scores indicate that even seemingly minor oversights in coding can have outsized impacts on system security.

Broader Implications for Windows Users​

While the CNCSoft-G2 system is not a typical Windows application, many Windows-based monitoring and control systems interface with industrial HMIs. This vulnerability serves as a stark reminder that even peripheral systems connected to Windows environments might introduce security risks. Windows administrators should consider similar security postures—regular updates, network segmentation, and vigilant monitoring—to protect not just office endpoints but also interconnected industrial systems.

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Mitigation and Best Practices​

Immediate Actions Recommended by Delta Electronics​

Delta Electronics has advised all users of CNCSoft-G2 to update their systems to version V2.1.0.20 or later. This update includes the necessary patches to address the buffer overflow flaw. Additionally, a detailed product cybersecurity advisory (Delta-PCSA-2025-00003) has been published to provide further technical guidance.

Defensive Cybersecurity Practices​

Both Delta Electronics and CISA recommend several industry best practices to help minimize the risk of exploitation:

• Exercise Caution with Unknown Links: Avoid clicking untrusted Internet links or opening unsolicited email attachments.
• Isolate Critical Systems: Do not expose control systems directly to the Internet. Instead, place them behind a dedicated firewall and segregate them from the main business network.
• Use Secure Remote Access Methods: When access is required from outside the defense perimeter, use a trusted virtual private network (VPN) or another secure remote access method.
• Regular Risk Assessments: Perform comprehensive impact analysis and risk assessments before deploying any new control measures.

Implementing these measures not only helps protect against the current CNCSoft-G2 vulnerability but also reinforces overall network defense strategies.

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The Industrial Control System (ICS) Landscape​

A Closer Look at the Environment​

The CNCSoft-G2 system is deployed across various global sectors, including energy and critical manufacturing. Because of its widespread use in critical infrastructure, vulnerabilities like this one have enormous potential consequences. Organizations operating in these sectors are encouraged to stay updated with the latest cybersecurity advisories and to monitor internal networks for any signs of intrusion.

Windows and ICS Security Interplay​

For professionals managing Windows environments that coexist alongside industrial control systems, the Cisco-like philosophy of “defense in depth” is invaluable. Isolating industrial systems, prioritizing updates, and enforcing robust access controls are practices that help mitigate risks across both IT and operational technology (OT) domains. The CNCSoft-G2 advisory further underscores the need for comprehensive cybersecurity strategies that bridge IT and OT.

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In Summary​

The Delta Electronics CNCSoft-G2 vulnerability is a wake-up call to the broader IT community, including Windows users engaged in industrial control or HMI monitoring. Here’s a quick recap:

• Issue: Heap-based buffer overflow in CNCSoft-G2 systems (versions V2.1.0.10 and prior) could lead to remote code execution.
• Risk Profile: Despite not being directly exploitable remotely, the vulnerability carries high risk scores (CVSS v4: 8.5; CVSS v3.1: 7.8) and affects critical infrastructure sectors.
• Recommended Action: Upgrade to CNCSoft-G2 v2.1.0.20 or later, and follow best security practices such as network isolation and secure remote access.
• Wider Context: Even if your core system is Windows-based, interconnected environments like HMIs underscore the need for layered security and prompt patch management.

As always, staying informed and proactive is key. Whether you’re responsible for an industrial network, a Windows server environment, or simply keeping an eye on cybersecurity trends, understanding these vulnerabilities—and the best practices to mitigate them—is essential in the evolving landscape of IT security.
Stay safe and secure your systems—because in today’s digital world, a single unchecked vulnerability can have far-reaching consequences.