CVE-2021-33542
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 · uneditedPhoenix Contact Classic Automation Worx Software Suite in Version 1.87 and below is affected by a remote code execution vulnerability. Manipulated PC Worx or Config+ projects could lead to a remote code execution when unallocated memory is freed because of incompletely initialized data. The attacker needs to get access to an original bus configuration file (*.bcp) to be able to manipulate data inside. After manipulation the attacker needs to exchange the original file by the manipulated one on the application programming workstation. Availability, integrity, or confidentiality of an application programming workstation might be compromised by attacks using these vulnerabilities. Automated systems in operation which were programmed with one of the above-mentioned products are not affected.
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 confidencePhoenix Contact Classic Automation Worx Software Suite versions 1.87 and below contains a memory corruption vulnerability where manipulated bus configuration files (*.bcp) cause unallocated memory to be freed due to incompletely initialized data, potentially allowing remote code execution on the application programming workstation.
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<= 1.87<= 1.87<= 1.87CVSS 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
- High
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:H/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 Phoenix Contact softwareCheck Program Files (x86) for folders named 'Phoenix Contact', 'Config+', 'Pc Worx', or check Windows Registry under HKLM\SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall for entries containing 'Phoenix Contact', 'Config+', 'Pc Worx', or 'Pc Worx Express'Affected if Any of the three affected products (Config+, Pc Worx, Pc Worx Express) are present on the system
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Determine installed versionRight-click the executable (Config+.exe, PcWorx.exe, or PcWorxExpress.exe) in the installation folder, select Properties, and check the File Version field under the Details tabAffected if The version number displayed is 1.87 or lower, or if no version is shown and the product is confirmed installed
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Verify .bcp file handling capabilitySearch the installation directory for files with .bcp extension, or attempt to open the application and check if it can import or load bus configuration files (*.bcp)Affected if The application can load or process .bcp files, which is the default functionality of these products
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Check for recent .bcp file activityReview the application log files (typically in the software's log or data folder) for recently opened or modified .bcp configuration files, or check the Windows临时 folder locations for recently accessed .bcp filesAffected if Any .bcp files have been opened recently, indicating the software has processed this file type
The environment is affected if any of the three Phoenix Contact products (Config+, Pc Worx, Pc Worx Express) are installed with version 1.87 or lower and the software is capable of loading .bcp configuration 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 dataOrganizations should update to a version above 1.87 when available, implement file integrity verification for .bcp configuration files, and restrict access to the application programming workstation to prevent unauthorized file substitution.
- Consultation6.0 h
- Implementation12.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-33542 — 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-2021-33542 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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