CVE-2022-21155: A specially crafted packet sent to the Fernhill SCADA Server Version 3.77 and earlier may cause an exception,

Q: How do I fix CVE-2022-21155?

scada server: upgrade to newer than 3.77. Exact commands for each OS are on this page.

Q: Is CVE-2022-21155 being exploited?

CVE-2022-21155 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2022-21155 affect?

CVE-2022-21155 affects scada server. Severity is high (CVSS 7.5). A 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.

Q: How urgent is CVE-2022-21155?

Priority 48/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 7.5REMOTEUPGRADE

CVE-2022-21155 is a high-severity flaw (CVSS 7.5) affecting scada server. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A 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.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	7.5 (High)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	1.1% (top 34%)
CISA exploited list	No
Weakness	CWE-400, CWE-755
Published	2022-04-12
Last modified	2026-06-17

Publisher (CNA): ICS-CERT · Vendor: fernhillsoftware

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2022-04-12 17:15 UTCPublished CVE record published
2026-06-17 04:25 UTCUpdated Record last modified

fernhillsoftware scada server UPGRADE

Affected: <= 3.77

Fixed in: newer than 3.77

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy scada-server || rpm -q scada-server || scada-server --version

2. UPGRADE to newer than 3.77 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade scada-server

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade scada-server

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2022-21155?

scada server: upgrade to newer than 3.77. Exact commands for each OS are on this page.

Is CVE-2022-21155 being exploited?

CVE-2022-21155 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2022-21155 affect?

CVE-2022-21155 affects scada server. Severity is high (CVSS 7.5). A 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.

How urgent is CVE-2022-21155?

Priority 48/100. High severity; Remotely exploitable, no login, no user action

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References

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