CVE-2025-61862: Fujielectric Monitouch V-sft RCE Flaw

CVE-2025-61862 Overview

CVE-2025-61862 is an out-of-bounds read vulnerability in the VS6ComFile!get_ovlp_element_size function of Fuji Electric V-SFT v6.2.7.0 and earlier. The flaw is triggered when a user opens a specially crafted V-SFT project file in the affected application. Successful exploitation can lead to information disclosure, abnormal application termination (ABEND), and arbitrary code execution within the context of the user. The issue is classified as [CWE-125] Out-of-Bounds Read and impacts engineering workstations used to configure Monitouch human-machine interface (HMI) panels in industrial environments.

Critical Impact

Attackers can execute arbitrary code on engineering workstations by convincing an operator to open a malicious V-SFT file, threatening the integrity of HMI configurations used in industrial control systems.

Affected Products

• Fuji Electric Monitouch V-SFT v6.2.7.0 and earlier
• V-SFT v6 VS6ComFile component
• Engineering workstations running vulnerable V-SFT installations

Discovery Timeline

• 2025-10-10 - CVE-2025-61862 published to NVD
• 2025-10-27 - Last updated in NVD database

Technical Details for CVE-2025-61862

Vulnerability Analysis

The vulnerability resides in the get_ovlp_element_size function exported by the VS6ComFile library, which V-SFT uses to parse overlap (ovlp) elements within V-SFT project files. The function reads element size metadata from the file without sufficiently validating the supplied length against the bounds of the allocated buffer. When a crafted file specifies an oversized or malformed element descriptor, the parser reads memory past the end of the intended structure.

The out-of-bounds read returns adjacent heap or stack memory to the calling code. That memory may contain pointers, file handles, or other sensitive runtime state. Depending on how the returned value is consumed downstream, the condition produces information disclosure, an application crash, or a corrupted control-flow primitive that an attacker can chain into arbitrary code execution.

Root Cause

The root cause is missing input validation in the V-SFT file parser. VS6ComFile!get_ovlp_element_size trusts a size field embedded in the input file and uses it to index into a buffer without verifying that the value remains within the parsed structure. This is a classic [CWE-125] pattern where attacker-controlled length metadata drives a read operation beyond an object boundary.

Attack Vector

Exploitation requires local file access and user interaction. An attacker delivers a crafted V-SFT project file to an engineer through email, removable media, a shared project repository, or a compromised vendor distribution. When the engineer opens the file in V-SFT v6.2.7.0 or earlier, the parser processes the malicious overlap element and triggers the out-of-bounds read. No authentication is required on the target system beyond the user's existing session.

No verified proof-of-concept code is available. Refer to the JVN Vulnerability Report for the coordinated disclosure details published by JPCERT/CC.

Detection Methods for CVE-2025-61862

Indicators of Compromise

• Unexpected crashes or ABEND events in the V-SFT process (V-SFT.exe) on engineering workstations
• V-SFT project files received from untrusted sources or arriving outside normal change-control channels
• Child processes spawned by V-SFT that do not match documented engineering workflows
• Windows Error Reporting entries referencing VS6ComFile.dll faults

Detection Strategies

• Monitor process telemetry for abnormal termination of V-SFT and for code execution originating from VS6ComFile.dll
• Inspect file shares and email gateways for V-SFT project files (.V8, .V9, related extensions) originating from external senders
• Correlate file-open events on engineering workstations with subsequent suspicious process, network, or memory activity

Monitoring Recommendations

• Enable application crash logging on all hosts running V-SFT and forward events to a centralized SIEM for review
• Apply allow-listing to restrict V-SFT execution to authorized engineering workstations only
• Audit project-file repositories for unauthorized modifications and unexpected file submissions

How to Mitigate CVE-2025-61862

Immediate Actions Required

• Inventory all systems running Fuji Electric Monitouch V-SFT v6 and identify installations at or below v6.2.7.0
• Block the receipt of V-SFT project files from untrusted external sources at email and web gateways
• Instruct engineering staff to open V-SFT project files only from verified internal repositories
• Isolate engineering workstations on a segmented network with no direct internet exposure

Patch Information

Fuji Electric distributes updated V-SFT v6 releases through its download portal. Apply the latest version published on the Fuji Electric Monitouch download site. Validate the updated version against the advisory referenced in the JVN Vulnerability Report before redeploying to production engineering hosts.

Workarounds

• Restrict V-SFT usage to dedicated, hardened engineering workstations with no general-purpose internet or email access
• Require digital signing or hash verification of V-SFT project files before they are opened
• Apply the principle of least privilege so that V-SFT runs under a non-administrative account, limiting the impact of successful code execution
• Enable operating system exploit mitigations such as Data Execution Prevention (DEP) and Address Space Layout Randomization (ASLR) on hosts running V-SFT

# Example: enumerate installed V-SFT versions on Windows engineering hosts
reg query "HKLM\SOFTWARE\WOW6432Node\Microsoft\Windows\CurrentVersion\Uninstall" /s /f "V-SFT" | findstr /i "DisplayName DisplayVersion InstallLocation"