Delta Electronics DOPSoft 2 Out-of-Bounds Write (CVE-2021-38406)
Published In CISA KEV since Sources: CVE.org, CISA ICS
What is affected, what to do
Delta Electronic DOPSoft 2 (Version 2.00.07 and prior) lacks proper validation of user-supplied data when parsing specific project files. This could result in multiple out-of-bounds write instances.
The vulnerability is being actively exploited; treat it as a priority. The available sources name no fixed version. Check the vendor guidance in the references below. Immediate actions, mitigation and detection rules are in the runbook below.
- Affected
- Delta Electronics DOPSoft 2
lte *..2.00.07
- Delta Electronics DOPSoft 2
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Metrics
7.8
Priority
XIEM Effective CVSS: highest available CVSS rating from NVD and vendor data.
Source: NVD, CVSS v3
7.8
CVSS v3
Severity High on the scale from 0 to 10.
Source: CVE.org, CISA ICS
76.4 %
EPSS score
High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
Source: FIRST EPSS, percentile 99.54
Show all metrics
- Severity
- Critical
Priority (0–325)
The priority score is a consolidated metric that condenses several individual signals into a single, action-guiding ranking: technical severity (CVSS), exploitation likelihood (EPSS), known-exploited status (KEV) and the context of the affected asset. The aim is to answer the only truly important question in vulnerability management: what first?
Read in glossary- 218.27 Methodology
Exploit maturity
An exploit is code or a technique that specifically uses a concrete vulnerability to force unintended behaviour — such as executing code or escalating privileges. It is the tool that turns a theoretical flaw into a practical attack.
Read in glossary- actively exploited
XIEM Effective CVSS
XIEM® is the tiered managed-security operating model from NEOSEC and a registered trademark of NEOSEC GmbH. It extends classic SIEM — the central collection, normalisation and correlation of security-relevant events — with endpoint forensics, network visibility and deception technology, and consolidates them into three building tiers: Sentry, Orchestrate and Command.
Read in glossary- 7.8 Methodology
CVSS v3
CVSS is the globally established, open standard for assessing the technical severity of a vulnerability on a scale from 0 to 10. It describes how easily a flaw can be exploited and what damage it can cause — but not how likely its actual exploitation is. CVSS and the complementary EPSS deliberately answer different questions.
Read in glossary- 7.8
EPSS score
The EPSS score is the absolute model output for an individual vulnerability: the estimated probability of real-world exploitation within the next 30 days, expressed as a value between 0 and 1 (i.e. 0 % to 100 %). A score of 0.42 means „the model estimates a 42 % chance of real-world exploitation within 30 days“.
Read in glossary- 76.4 %
- High — model estimates ≥ 50% chance of real-world exploitation within 30 days.
EPSS percentile
The EPSS percentile is the relative position of a vulnerability within all EPSS-scored CVEs, expressed as a value between 0 and 1. A percentile of 0.90 means „this CVE has a higher EPSS score than 90 % of all other scored CVEs“. Unlike the EPSS score, it is not a probability — but a positioning within a ranking.
Read in glossary- 99.54
- Critical — this CVE ranks in the top fifth of all CVEs scored today (rank ≥ 80%).
KEV status
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- Actively exploited
- Published
In CISA KEV since
The KEV catalogue is a list maintained by the US authority CISA of vulnerabilities for which active exploitation in the wild has been confirmed. It answers not the question „how severe?“ but „is it already being attacked?“ — thereby sharply prioritising patching.
Read in glossary- CISA assessment (SSVC)
- Exploitation: active · not automatable · Technical impact: total
- Source: CISA Vulnrichment, as of 4 February 2025
CWE
CWE is a catalogue of typical weakness types in software and hardware — such as flawed input validation, unsafe memory handling or poor authentication. Where a CVE names a concrete vulnerability in a concrete product, a CWE describes the underlying class of defect.
Read in glossary- CWE-787
Response and mitigation
Why act now?
Prioritisation rationale
Exploitation requires local execution and user interaction but no authentication. One crafted project opened by an engineer is enough for full code execution, with high impact on confidentiality, integrity and availability. Exploitation likelihood is rated very high, placing this among the CVEs most likely to be exploited, while CISA reports no known ransomware use. The typical target is the engineering workstation that programs Delta DOP HMIs in manufacturing, building automation and utilities: a compromised EWS becomes a beachhead into the OT zone and a vehicle for tampered HMI projects. Organisations whose DOPSoft hosts have email or internet access, or that routinely receive files from external integrators, should treat this as high to critical. Where workstations are strictly isolated behind a controlled transfer point, medium is defensible, but the upgrade or replacement should still be scheduled promptly.
Runbook step 1
Immediate response (0-24 h)
- Build the inventory: Identify every engineering workstation (EWS) and field-service laptop running Delta Electronics DOPSoft 2, using software inventory, an EDR query for the DOPSoft install path, or uninstall registry keys. All versions up to and including 2.00.07 are affected.
- Confirm patch status: The context does not name a fixed release. Check the Delta Electronics vendor advisory and the corresponding CISA ICS advisory for the fixed version or the recommended successor product. Until that is confirmed, treat the vulnerability as unpatched and rely on the compensating controls below.
- Ban opening untrusted project files now: The bug is triggered when DOPSoft parses a crafted project file. Formally instruct OT engineering, maintenance staff and external integrators to open project files only from the internal, version-controlled project archive. Files from email attachments, downloads or contractor USB sticks are not permitted.
- Quarantine recently received project files: Isolate project files that arrived via email, file sharing or removable media over recent weeks. Compare their hashes against the approved archive.
- Prioritise EWS with internet or email access: Temporarily cut these hosts off from the office network, or uninstall DOPSoft from them, until the situation is clarified.
Runbook step 2
Mitigation layers
- Network segmentation (IEC 62443 zones/conduits): Place DOPSoft workstations in a dedicated engineering zone with no direct internet, webmail or office access. Route all file handover through a controlled transfer point, such as a scanning kiosk or transfer server. Restrict EWS egress to a minimal allowlist, with only the download path to the DOP panels permitted towards the HMI zone.
- Media and file control: Block USB mass storage on EWS via device control, allowing only approved, encrypted media. At the mail gateway, block or quarantine DOPSoft project file extensions for OT recipients. Derive the exact extensions from the local installation's file associations.
- Endpoint hardening: Enforce Windows Exploit Protection (DEP, ASLR including mandatory/bottom-up, CFG) for the DOPSoft executable. Add application allowlisting (AppLocker/WDAC) so binaries and scripts cannot launch from user-profile and temp paths.
- IAM/least privilege: Code runs in the context of the current process, so run DOPSoft as a standard user only. Avoid local admin rights and never keep domain-admin sessions open on EWS. Use separate, non-privileged accounts for engineering work.
- Integrity assurance: Keep approved project files hashed or signed in version control, and allow engineers to open files only from that repository (ISO 27001 A.8.32 change management).
Runbook step 3
Detection rules
- EDR/Sysmon EID 1 – suspicious child processes: The DOPSoft process spawns
cmd.exe,powershell.exe,rundll32.exe,mshta.exe,wscript.exeorregsvr32.exe. KQL:DeviceProcessEvents | where InitiatingProcessFileName has "DOPSoft" and FileName in~ ("cmd.exe","powershell.exe","rundll32.exe","mshta.exe","wscript.exe","regsvr32.exe"). Verify the image name against your own installation. - Sysmon EID 3 / Zeek conn.log – network activity: The DOPSoft process opens outbound connections beyond the HMI subnet, especially to public IP addresses. Sigma shape:
Image|contains: 'DOPSoft'ANDDestinationIpnot in OT-HMI ranges. - Sysmon EID 11 – file creation: The DOPSoft process drops
.exe,.dll,.ps1or.batfiles into%TEMP%,%APPDATA%or autostart locations. Pair this with Sysmon EID 13 for Run-key writes. - Windows Application log EID 1000/1001 (WER): Repeated DOPSoft crashes right after a project file is opened suggest failed out-of-bounds write attempts. Preserve the file and hand it to forensics.
- Mail/proxy logs: Correlate project-file attachments sent to OT staff from external or newly registered sender domains, as well as project-file downloads from file-hosting services.
- EDR/Sysmon EID 1 – suspicious child processes: The DOPSoft process spawns
Detection rules
No NEOSEC detection rule is available for this vulnerability yet.
Classification under NIS2 and CRA
Rule-based classification from exploitation status and severity. It does not replace a case-by-case assessment.
NIS2
NIS2 is EU Directive (EU) 2022/2555 to raise the level of cybersecurity across the Union. It substantially broadens obligations compared with the first NIS directive: more sectors, mandatory risk management, staged reporting duties and personal accountability of senior management.
Read in glossary- Actively exploited: treat the vulnerability as a priority in vulnerability handling under Art. 21(2)(e) NIS2. If it is exploited in your environment, check the reporting obligation under Art. 23 (early warning within 24 hours).
CRA
The CRA is EU Regulation (EU) 2024/2847 setting horizontal cybersecurity requirements for „products with digital elements“ — from industrial controllers and software to connected consumer devices. For the first time manufacturers must ensure security across the entire product lifecycle, handle vulnerabilities and provide security updates.
Read in glossary- Since 11.09.2026, manufacturers of affected products with digital elements must report actively exploited vulnerabilities under Art. 14 CRA, with an early warning within 24 hours via ENISA's single reporting platform.
ISO/IEC 27001
ISO/IEC 27001 is the internationally leading standard for an information security management system (ISMS). It describes a risk-based, process-oriented framework to systematically plan, implement, review and improve information security.
Read in glossary- Control A.8.8, management of technical vulnerabilities: assess relevance to your systems, plan remediation and keep evidence.
Description
Delta Electronic DOPSoft 2 (Version 2.00.07 and prior) lacks proper validation of user-supplied data when parsing specific project files. This could result in multiple out-of-bounds write instances. An attacker could leverage this vulnerability to execute code in the context of the current process.
Source: NVD (NIST), cvelistv5, CISA KEV Catalog, cisa_ics_advisory, CVE.org (MITRE)
Affected products
The following versions are affected. Older releases of the same product line are also vulnerable unless stated otherwise.
| Affected versions | Fixed in | ||
|---|---|---|---|
| Delta Electronics | DOPSoft 2 |
|
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| deltaww | dopsoft |
|
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Vendors and products
Weakness classes (CWE)
CWE-787Out-of-bounds Write
Base
The product writes data past the end, or before the beginning, of the intended buffer.
Entry at MITRE CWE-787
Public exploit references
Publicly reported proof-of-concepts, exploit modules and detection templates for this vulnerability. NEOSEC links to the original sources only and does not provide any exploit code.
| CISA KEV Catalog | CISA Known Exploited Vulnerability (opens in a new tab)cisa.gov | actively exploited |
References & sources
- us-cert.cisa.govics/advisories/icsa-21-252-02x_refsource_MISC, Third-party advisory, US government resource
- cisa.govknown-exploited-vulnerabilities-catalog?field_cve=CVE-2021-38406government-resource, US government resource
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<a href="https://intel.neosec.eu/en/cve/CVE-2021-38406"><img src="https://intel.neosec.eu/badge/cve/CVE-2021-38406.svg?lang=en" alt="CVE-2021-38406 – NEOSEC Intel" height="20"></a>