CVE-2020-5807
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 · uneditedAn unauthenticated remote attacker can send data to RsvcHost.exe listening on TCP port 5241 to add entries in the FactoryTalk Diagnostics event log. The attacker can specify long fields in the log entry, which can cause an unhandled exception in wcscpy_s() if a local user opens FactoryTalk Diagnostics Viewer (FTDiagViewer.exe) to view the log entry. Observed in FactoryTalk Diagnostics 6.11. All versions of FactoryTalk Diagnostics are 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 confidenceAn unauthenticated remote attacker can send specially crafted data to RsvcHost.exe listening on TCP port 5241 to inject entries with excessively long fields into the FactoryTalk Diagnostics event log. When a legitimate local user subsequently opens FTDiagViewer.exe to view these log entries, the overly long field values trigger an unhandled exception in the wcscpy_s() function, causing the viewer to crash.
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<= 6.11CVSS 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
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 FactoryTalk Diagnostics is installedCheck installed programs or product registry for FactoryTalk Diagnostics componentAffected if The product is present on the system
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Check installed version against affected rangeLocate and read the FactoryTalk Diagnostics version information, then compare to 6.11Affected if Version is 6.11 or lower
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Verify RsvcHost.exe is listening on TCP port 5241Run netstat -an | findstr 5241 or use PortQry to check if port 5241 is in listening stateAffected if Port 5241 is open and accepting connections (RsvcHost.exe service running)
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Inspect FactoryTalk Diagnostics log for unusually long field entriesOpen the diagnostic log storage location and search for entries with abnormally long string fields, or use FTDiagViewer.exe to browse recent entriesAffected if Log contains entries with excessively long field values that exceed normal length
A user is affected if FactoryTalk Diagnostics version 6.11 or lower is installed AND port 5241 is accessible, allowing potential injection of malicious log entries with oversized fields.
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 dataRestrict network access to TCP port 5241 (e.g., firewall rules, network segmentation) to prevent unauthenticated attackers from injecting malicious log entries, and limit local user access to FactoryTalk Diagnostics Viewer until an official vendor patch is released.
- Consultation2.0 h
- Implementation4.0 h
- Testing3.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-5807 — 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-2020-5807 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
- No spam, self-promotion, credentials, or personal data