dbcve.org
Webaccess\/scadaApplication · Advantech

CVE-2021-32943

CRITICAL · 9.8 CVSS v3.1 Published 2021-08-10
Fix available
A fix is available. Upgrade to 8.4.5 / 9.0.1 or later.
See remediation →
100/100
Remediation priority · Urgent
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
The affected product is vulnerable to a stack-based buffer overflow, which may allow an attacker to remotely execute arbitrary code on the WebAccess/SCADA (WebAccess/SCADA versions prior to 8.4.5, WebAccess/SCADA versions prior to 9.0.1).

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

WebAccess/SCADA versions prior to 8.4.5 and 9.0.1 contain a stack-based buffer overflow vulnerability that allows remote attackers to execute arbitrary code by sending specially crafted network packets to the affected service.

MitigationUpgrade WebAccess/SCADA to version 8.4.5 or later, or version 9.0.1 or later. If immediate patching is not possible, network segmentation and firewall rules should restrict access to SCADA management interfaces.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Webaccess\/scadaApplication
Affected:< 8.4.5>= 9.0, < 9.0.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Identify WebAccess/SCADA installation
    Locate the WebAccess/SCADA installation directory and find the version information file or executable. Common locations include C:\WebAccess or installation-specific paths. Check the About or Version dialog within the SCADA application interface.
    Affected if The installed version is less than 8.4.5, or is 9.0.0 (the 9.0 branch before 9.0.1)
  2. Determine version branch
    Confirm whether the installation is version 8.x or 9.x. This determines which vulnerability range applies. Compare your installed version to the affected ranges: version 8.x below 8.4.5, or version 9.x below 9.0.1.
    Affected if Version falls into either < 8.4.5 or >= 9.0.0 and < 9.0.1
  3. Identify the affected network service
    WebAccess/SCADA runs as a Windows service. Open Windows Services (services.msc) and locate the WebAccess service. This service listens on network ports and is the component that processes the vulnerable network packets.
    Affected if The WebAccess/SCADA service is installed and running
  4. Check network exposure
    Use netstat or a port scanner to determine which ports the WebAccess/SCADA service is listening on and whether those ports are accessible from network segments outside the protected OT environment. Typical ports include 80, 443, or configured SCADA communication ports.
    Affected if The service port is bound to a network interface accessible from outside the local host or trusted network segments

You are affected if the installed WebAccess/SCADA version is below 8.4.5 for the 8.x branch, or below 9.0.1 for the 9.x branch, AND the service is running and network-accessible.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

dbcve · scoped
Upgrade available Upgrade to 8.4.5 / 9.0.1 or later
Fixed in 8.4.59.0.1
Interim mitigation

Upgrade WebAccess/SCADA to version 8.4.5 or later, or version 9.0.1 or later. If immediate patching is not possible, network segmentation and firewall rules should restrict access to SCADA management interfaces.

Recommended fix High confidence

WebAccess/SCADA 8.4.5 (for 8.x branch) or WebAccess/SCADA 9.0.1 (for 9.x branch) or later respective branches

  1. 1. Identify the currently installed WebAccess/SCADA version through the system administration interface or system information
  2. 2. For systems running version 8.x < 8.4.5: Plan upgrade to version 8.4.5 or later in the 8.x branch
  3. 3. For systems running version 9.0.x: Plan upgrade to version 9.0.1 or later in the 9.x branch
  4. 4. Review Advantech WebAccess/SCADA upgrade documentation for your specific version
  5. 5. Create a complete backup of the system configuration and project data before upgrading
  6. 6. Schedule maintenance window as upgrade may require system restart
  7. 7. Perform upgrade in a test/staging environment first to verify compatibility with existing configurations
  8. 8. Apply the upgrade following vendor documentation
Caveat Low risk - this is a security-focused patch upgrade; however, test in staging environment first as with any SCADA system upgrade

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Webaccess\/scada Scoped from the published advisory
  • Consultation8.0 h
  • Implementation4.0 h
  • Testing16.0 h
  • Review / QA8.0 h
36.0 hours of engineering $6,160
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $9,856.

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-32943 in production — separate from our analysis above.

No notes yet

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What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data