CVE-2021-40837
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 vulnerability affecting F-Secure antivirus engine before Capricorn update 2022-02-01_01 was discovered whereby decompression of ACE file causes the scanner service to stop. The vulnerability can be exploited remotely by an attacker. A successful attack will result in denial-of-service of the antivirus engine.
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 confidenceThe vulnerability exists in F-Secure antivirus engine's ACE file decompression routine. When processing a specially crafted ACE archive file, the scanner service encounters an error that causes it to crash, resulting in denial-of-service. The attacker can exploit this remotely by delivering the malicious ACE file to the target system.
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< 2022-02-01_01< 2022-02-01_01< 2022-02-01_01< 2022-02-01_01< 2022-02-01_01< 2022-02-01_01CVSS 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
- Low
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
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 F-Secure productsRun system inventory or check installed software list to find F-Secure products such as Atlant, Internet Gatekeeper, Linux Security, Security Cloud, or Elements Endpoint products.Affected if Any of the affected F-Secure products are installed on the system.
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Check F-Secure engine versionUse F-Secure command-line tools or product interface to query the engine version. Compare against the fixed version 2022-02-01_01.Affected if The installed engine version is earlier than 2022-02-01_01.
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Verify ACE file scanning is enabledCheck the F-Secure scanner configuration to confirm if ACE archive decompression and scanning functionality is enabled in the real-time or on-demand scan settings.Affected if ACE file scanning is enabled and the engine version is vulnerable.
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Review scan logs for ACE-related crashesExamine F-Secure scan logs and system event logs for crashes or errors related to ACE archive processing occurring around the time of scan events.Affected if Scan logs show crashes or errors when processing ACE files on a vulnerable version.
A system is affected if it runs any F-Secure product from the affected list with an engine version earlier than 2022-02-01_01 and has ACE file scanning enabled.
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.
dbcve · scoped2022-02-01_01
Apply the Capricorn update (2022-02-01_01 or later) to the F-Secure antivirus engine. Organizations should also implement file-type filtering at email gateways and proxy levels to block unsolicited ACE file attachments as a defense-in-depth measure.
2022-02-01_01 (Capricorn update)
- Identify the specific F-Secure product in use from the affected list: Atlant, Internet Gatekeeper, Linux Security, Security Cloud, Elements Endpoint Detection And Response, or Elements Endpoint Protection
- Upgrade the product to version 2022-02-01_01 (Capricorn update) or later
- Verify the scanner service remains running after the update
- Test that ACE file decompression no longer causes the scanner service to stop
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 h
- Implementation2.0 h
- Testing2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-40837 — 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-2021-40837 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