CVE-2025-7227: Invt VT Designer RCE Vulnerability

CVE-2025-7227 Overview

CVE-2025-7227 is an out-of-bounds write vulnerability [CWE-787] in INVT VT-Designer, a human-machine interface (HMI) configuration tool used in industrial control system environments. The flaw resides in the parser that processes PM3 files and stems from missing validation of user-supplied data. An attacker who convinces a user to open a crafted PM3 file or visit a malicious page can write past the end of an allocated buffer. Successful exploitation leads to arbitrary code execution in the context of the current process. The issue was tracked through the Zero Day Initiative as ZDI-CAN-25550 and disclosed in advisory ZDI-25-478.

Critical Impact
Arbitrary code execution on engineering workstations running INVT VT-Designer, potentially providing a foothold into operational technology (OT) environments.

Affected Products

INVT VT-Designer version 2.1.13
INVT HMI engineering workstations using VT-Designer for project configuration
Industrial systems that exchange PM3 project files between engineers

Discovery Timeline

2025-07-21 - CVE-2025-7227 published to NVD
2026-06-17 - Last updated in NVD database

Technical Details for CVE-2025-7227

Vulnerability Analysis

The vulnerability exists in the routine that parses PM3 files within INVT VT-Designer. The parser reads attacker-controlled fields from the file and uses them to write data into a fixed-size structure without verifying that the supplied length stays within bounds. The resulting out-of-bounds write corrupts adjacent memory, including function pointers, return addresses, or object metadata. An attacker can shape the corrupted memory to redirect execution into attacker-supplied instructions. Because VT-Designer typically runs with the privileges of an interactive engineer, code execution can lead to lateral movement toward connected programmable logic controllers (PLCs) and HMIs.

Root Cause

The root cause is improper input validation when consuming fields from the PM3 file format. The parser trusts size or offset values embedded in the file and copies data into a buffer that was sized for typical, well-formed input. This pattern matches [CWE-787] out-of-bounds write, where bounds checks are absent or incorrectly implemented before a memory write.

Attack Vector

Exploitation requires user interaction. An attacker delivers a malicious PM3 file through email, a shared project repository, removable media, or a web download. When an engineer opens the file in VT-Designer, the parser processes attacker-controlled data and triggers the out-of-bounds write. The attack vector is local and the attack complexity is low, but exploitation depends on social engineering to reach an operator. Refer to the Zero Day Initiative Advisory ZDI-25-478 for additional technical context.

No verified proof-of-concept code is publicly available. The vulnerability mechanism centers on a malformed PM3 structure that drives the parser to write attacker-controlled bytes beyond the end of an allocated buffer, ultimately hijacking control flow.

Detection Methods for CVE-2025-7227

Indicators of Compromise

Unexpected child processes spawned by VT-Designer.exe, particularly command interpreters such as cmd.exe, powershell.exe, or rundll32.exe.
Crash events or Windows Error Reporting entries citing access violations inside VT-Designer modules during PM3 file parsing.
PM3 files arriving from untrusted sources, especially via email attachments, web downloads, or removable media.
New persistence artifacts, scheduled tasks, or outbound network connections originating from engineering workstations running VT-Designer.

Detection Strategies

Monitor process lineage for VT-Designer to flag any child process that is not part of the normal engineering workflow.
Inspect file telemetry for PM3 files written or opened outside known project directories.
Use EDR behavioral rules to identify exploitation patterns such as shellcode execution from a document parser process.

Monitoring Recommendations

Forward endpoint, process, and file events from engineering workstations to a centralized analytics platform for correlation.
Alert on outbound network connections initiated by VT-Designer.exe, which should rarely communicate externally.
Track delivery of PM3 attachments through email security gateways and file sharing services.

How to Mitigate CVE-2025-7227

Immediate Actions Required

Restrict opening of PM3 files to trusted, internally generated project artifacts only.
Isolate engineering workstations running VT-Designer on a segmented OT or engineering VLAN with strict egress controls.
Train engineers to verify the origin of any PM3 file before opening it in VT-Designer.
Remove or disable VT-Designer on hosts that no longer require it.

Patch Information

Review the Zero Day Initiative Advisory ZDI-25-478 and the INVT vendor channel for the latest fixed version of VT-Designer. Apply the vendor-supplied update to all engineering workstations once available. Until a confirmed patched release is identified, treat all installations of version 2.1.13 as vulnerable.

Workarounds

Block PM3 file attachments at email and web gateways unless explicitly required for business operations.
Open untrusted PM3 files only inside an isolated virtual machine without network access to production OT systems.
Apply application allowlisting to prevent unauthorized child processes from spawning under VT-Designer.exe.
Enforce least privilege on engineering accounts so that successful exploitation does not yield administrative control.

bash

# Example: block PM3 attachments at a mail gateway and audit local copies
# (adjust to your environment and policy engine)
find /var/mail -type f -name '*.pm3' -exec quarantine {} \;
auditctl -w /Projects/ -p wa -k vt_designer_pm3_write