CVE-2021-40836
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 was discovered whereby scanning MS outlook .pst files can lead to denial-of-service. 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 confidenceF-Secure antivirus engine contains a vulnerability in its MS Outlook .pst file scanning component. When scanning a specially crafted or malformed .pst file, the engine can be triggered to crash or become unresponsive, resulting in denial-of-service of the antivirus functionality.
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 dataall versionsall versionsall versionsall versionsall versionsall versionsCVSS 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
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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 installed F-Secure productRun a system inventory or package query to list installed security software. Look for packages named: F-Secure Atlant, F-Secure Internet Gatekeeper, F-Secure Linux Security, F-Secure Elements Endpoint Detection And Response, or F-Secure Elements Endpoint Protection.Affected if Any of these F-Secure products are installed on the system
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Confirm product versionUse the package manager or vendor tool to query the installed version of the identified F-Secure product.Affected if The installed version matches any version of the affected products listed (all versions are vulnerable)
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Verify .pst scanning is enabledCheck the F-Secure configuration settings for the scanning engine. Look for settings related to Outlook .pst file scanning or email archive scanning. This may be in the product console, configuration files, or command-line tools provided by F-Secure.Affected if PST file scanning or email archive scanning is enabled in the scanning profile
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Confirm active scanning modeDetermine if real-time scanning (on-access) or on-demand scheduled scanning is active. Check whether the scanning engine is configured to automatically scan files including email archives.Affected if Real-time or automatic on-demand scanning of .pst files is configured and active
A user is affected if any of the listed F-Secure products are installed with .pst or email archive scanning enabled, as this is the condition that triggers the vulnerable code path when processing malicious .pst 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 dataApply vendor-supplied patches or updates from F-Secure. As an interim workaround, consider excluding .pst files from automated scanning until the patch is deployed, if the vendor recommends this approach.
- Consultation1.0 h
- Implementation1.0 h
- Testing1.0 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 $1,200.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-40836 — 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-2021-40836 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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A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.
- 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