CVE-2023-2866
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 · uneditedIf an attacker can trick an authenticated user into loading a maliciously crafted .zip file onto Advantech WebAccess version 8.4.5, a web shell could be used to give the attacker full control of the SCADA server.
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 · moderate confidenceAdvantech WebAccess 8.4.5 has a file handling vulnerability where processing a maliciously crafted .zip file leads to deployment of a web shell. An authenticated user must be tricked into loading the malicious file, which when extracted by the application, places executable code on the server, granting the attacker remote code execution and full control of the SCADA server.
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= 8.4.5CVSS 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
- Local
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 checksWork through these to decide whether this CVE applies to you.
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Identify installed WebAccess versionCheck the WebAccess installation directory or registry for the version number, typically found in the installation manifest or about screen of the applicationAffected if The installed version is exactly 8.4.5
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Verify file upload or zip import functionalityLocate the WebAccess configuration or feature settings that handle file uploads, particularly .zip file imports. Check if this feature is enabled in the web interface or configuration filesAffected if The zip file import/upload feature is enabled and accessible to authenticated users
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Inspect web root directories for unauthorized filesSearch the WebAccess web root directories (typically the www or webapps folder) for newly created or unexpected files with extensions such as .asp, .jsp, .php, .exe, or .bat that were not part of the original installationAffected if Suspicious executable or script files exist in the web directories that were not intentionally deployed
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Review authentication logs for file import activityExamine WebAccess server logs, particularly authentication and file operation logs, for entries indicating that .zip files were uploaded or extracted by usersAffected if There are log entries showing authenticated users importing zip files that could contain malicious payloads
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Check for web shell indicatorsLook for known web shell patterns in web-accessible directories, including unusual JSP, ASP, or PHP files with content containing common web shell functions or encoded commandsAffected if Web shell files or suspicious scripts are present in web-accessible directories
A system is affected if it runs Advantech WebAccess version 8.4.5 with the zip file import feature enabled and evidence exists of unauthorized files or web shells in the web directory.
Generated from the published advisory. Verify against your own configuration.
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.
From vendor dataUpgrade to a patched version of WebAccess if available; otherwise, implement strict file upload validation, restrict .zip file processing, monitor for web shell artifacts, and apply network segmentation to isolate the SCADA server.
- Consultation8.0 h
- Implementation16.0 h
- Testing12.0 h
- Review / QA8.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $12,352.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-2866 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2023-2866 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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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.
- 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