CVE-2024-4192: Deltaww CNCSoft-G2 Buffer Overflow Flaw

CVE-2024-4192 Overview

CVE-2024-4192 is a stack-based buffer overflow [CWE-121] in Delta Electronics CNCSoft-G2, a human-machine interface (HMI) software used in industrial control system (ICS) environments. The vulnerability stems from insufficient validation of user-supplied data length before copying it into a fixed-size stack buffer. An attacker who convinces a local user to open a crafted file can execute arbitrary code in the context of the current process. CISA published the issue in advisory ICSA-24-121-01, noting the impact on critical manufacturing environments that rely on Delta Electronics CNC workstations.

Critical Impact
Successful exploitation enables arbitrary code execution on operator workstations running CNCSoft-G2, providing a foothold into industrial control networks.

Affected Products

Delta Electronics CNCSoft-G2 (all versions prior to the vendor fix referenced in ICSA-24-121-01)
Windows workstations running CNCSoft-G2 as an HMI client
Industrial control system deployments using Delta CNC controllers

Discovery Timeline

2024-04-30 - CVE-2024-4192 published to the National Vulnerability Database
2024-04-30 - CISA releases ICS advisory ICSA-24-121-01
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2024-4192

Vulnerability Analysis

CNCSoft-G2 parses user-supplied files and network input as part of its HMI functions. The affected code path copies attacker-controlled data into a fixed-length stack buffer without enforcing a length check against the destination size. When the input exceeds the buffer capacity, adjacent stack memory, including saved return addresses and frame pointers, is overwritten.

An attacker can shape the overflow to redirect execution flow. Because the process is typically running under the interactive user, successful exploitation grants code execution with the privileges of the operator or engineer using the HMI. This class of flaw is tracked as [CWE-121] Stack-based Buffer Overflow.

The attack vector is local and requires user interaction, per the CVSS metrics. Delivery typically involves a malicious project file, configuration file, or crafted payload opened in CNCSoft-G2. No authentication is needed at the application level.

Root Cause

The root cause is a missing bounds check prior to a memory copy operation. The routine trusts the length field or terminator supplied by attacker-controlled input rather than validating it against the destination buffer size. Compilers may emit stack canaries, but reliable exploitation techniques remain viable against ICS software that ships without full modern mitigations such as consistent Control Flow Guard and ASLR opt-in for every module.

Attack Vector

Exploitation requires an operator to open a malicious file in CNCSoft-G2. Threat actors targeting industrial environments commonly deliver such files through spear-phishing engineers, tampering with USB media used on air-gapped hosts, or compromising vendor and integrator supply chains. Once the crafted file is parsed, the overflow triggers and the attacker gains code execution on the engineering workstation.

No verified public proof-of-concept code is available for CVE-2024-4192. Refer to the CISA ICS Security Advisory ICSA-24-121-01 for vendor-coordinated technical details.

Detection Methods for CVE-2024-4192

Indicators of Compromise

Unexpected child processes spawned by CNCSoft-G2.exe such as cmd.exe, powershell.exe, or rundll32.exe
CNCSoft-G2 process crashes or Windows Error Reporting entries referencing access violations in the parser modules
Outbound network connections initiated by CNCSoft-G2 to non-Delta or non-corporate infrastructure
Suspicious project files, .dop, or configuration files arriving via email, removable media, or shared drives on engineering workstations

Detection Strategies

Monitor process lineage on HMI and engineering hosts for CNCSoft-G2 spawning interactive shells or scripting hosts
Alert on module loads and DLL sideloading events under the CNCSoft-G2 install directory
Correlate file open events for CNCSoft-G2 project files with subsequent process crashes or exceptions

Monitoring Recommendations

Ingest Windows Sysmon and EDR telemetry from operator workstations into a centralized SIEM for behavioral analytics
Track application crash telemetry (Event ID 1000, 1001) referencing CNCSoft-G2 binaries as a signal of exploitation attempts
Baseline normal file transfer channels into the OT environment and alert on out-of-band delivery of CNCSoft-G2 file types

How to Mitigate CVE-2024-4192

Immediate Actions Required

Upgrade CNCSoft-G2 to the version specified in CISA advisory ICSA-24-121-01 on all engineering and operator workstations
Restrict which users can open external CNCSoft-G2 project files and enforce review of files originating outside the OT network
Isolate HMI and engineering workstations behind ICS-aware firewalls and disable direct internet access

Patch Information

Delta Electronics released a fixed version of CNCSoft-G2 as described in CISA ICS Security Advisory ICSA-24-121-01. Administrators should download the updated installer directly from Delta Electronics and validate its integrity before deployment across the fleet.

Workarounds

Block untrusted CNCSoft-G2 project files at email gateways and removable-media scanning stations
Apply application allowlisting so CNCSoft-G2 cannot spawn interactive shells or scripting interpreters
Enforce least-privilege user accounts for engineers running CNCSoft-G2 to limit the blast radius of code execution
Follow CISA ICS defensive guidance, including network segmentation between the enterprise and OT zones

bash

# Example Windows application allowlisting rule (WDAC/AppLocker concept)
# Deny CNCSoft-G2.exe from launching common living-off-the-land binaries
# Review and adapt paths to match the installed environment before deployment
New-AppLockerPolicy -RuleType Path -User Everyone -Action Deny \
  -Path "%ProgramFiles%\Delta Industrial Automation\CNCSoft-G2\CNCSoft-G2.exe" \
  -Condition "ChildProcess: cmd.exe, powershell.exe, wscript.exe, cscript.exe, rundll32.exe"