CVE-2022-21155
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 · uneditedA specially crafted packet sent to the Fernhill SCADA Server Version 3.77 and earlier may cause an exception, causing the server process (FHSvrService.exe) to exit.
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 confidenceThis is a denial-of-service vulnerability in Fernhill SCADA Server versions 3.77 and earlier. An unauthenticated remote attacker can send a specially crafted packet to the FHSvrService.exe process, causing it to crash and exit, disrupting SCADA operations.
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<= 3.77CVSS 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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Identify if Fernhill SCADA Server is installedCheck the Windows Programs and Features list (appwiz.cpl) or look for Fernhill SCADA installation directories, typically under C:\Program Files\Fernhill SCADA or C:\Program Files (x86)\Fernhill SCADAAffected if The product is present on the system
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Determine installed version of Fernhill SCADA ServerOpen the Windows Programs and Features list, locate Fernhill SCada Server, and note the version column, or check the version property of FHSvrService.exe in the installation bin folderAffected if The installed version is 3.77 or any version lower (for example, 3.76, 3.75, etc.)
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Verify the FHSvrService.exe process is runningOpen Windows Task Manager or use command 'tasklist /FI "IMAGENAME eq FHSvrService.exe"' to check if the service process is activeAffected if The FHSvrService.exe process is running and the version is <= 3.77
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Assess network exposure of the SCADA serverCheck firewall rules and listening ports on the server. Use 'netstat -an | findstr LISTENING' to identify ports the FHSvrService.exe is bound to, and review inbound firewall rules for the server IPAffected if The SCADA server is directly accessible from untrusted networks on the ports it listens to (typically UDP/TCP 2019 or similar SCADA ports)
A user is affected if Fernhill SCADA Server version 3.77 or earlier is installed, the FHSvrService.exe process is running, and the server is network-accessible to untrusted attackers.
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 available; prior to patch deployment, implement network segmentation and firewall rules to restrict access to the SCADA server to only authorized hosts and protocols.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,600.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2022-21155 — 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-2022-21155 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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