CVE-2021-27475
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 · uneditedRockwell Automation Connected Components Workbench v12.00.00 and prior does not limit the objects that can be deserialized. This vulnerability allows attackers to craft a malicious serialized object that, if opened by a local user in Connected Components Workbench, may result in remote code execution. This vulnerability requires user interaction to be successfully exploited.
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 confidenceConnected Components Workbench fails to validate or restrict objects during deserialization, allowing attackers to embed malicious code in serialized objects. When a user opens a crafted malicious file, the deserialization process executes the embedded payload, leading to remote code execution.
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<= 12.00.00CVSS 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
- Changed
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/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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Verify Connected Components Workbench is installedCheck for the product in Windows Programs and Features, or look for the installation directory under C:\Program Files\Rockwell Automation\Connected Components WorkbenchAffected if The software is not present on the system, the user is not affected by this CVE
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Locate the installed version numberOpen the application and navigate to Help > About, or check the version in the program's executable properties (right-click CCW.exe > Properties > Details). Alternatively, check the Windows registry under HKLM\SOFTWARE\Rockwell Automation\Connected Components Workbench for the Version valueAffected if Unable to determine the version, further investigation is needed
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Compare your installed version against the affected rangeIf the version is 12.00.00 or lower, the installation is within the affected range. Versions higher than 12.00.00 are not affectedAffected if Installed version is 12.00.00 or lower - the environment is vulnerable to CVE-2021-27475
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Identify deserialization file associationsConnected Components Workbench uses .ccwrg and .ccwfxl file extensions for project files. Check if these file types are associated with the application by looking at Default Programs or examining the file associations in the Windows registry under HKCR\.ccwrg and HKCR\.ccwfxlAffected if These file associations exist, opening a malicious crafted file could trigger the deserialization vulnerability
A user is affected if Connected Components Workbench version 12.00.00 or lower is installed and the deserialization file associations (.ccwrg, .ccwfxl) are active, allowing potential RCE when opening untrusted project files.
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 dataApply the vendor patch when released; avoid opening serialized objects from untrusted sources; implement application whitelisting and network segmentation as defense-in-depth layers.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-27475 — 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-2021-27475 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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- 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
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