CVE-2021-3641
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 · uneditedImproper Link Resolution Before File Access ('Link Following') vulnerability in the EPAG component of Bitdefender Endpoint Security Tools for Windows allows a local attacker to cause a denial of service. This issue affects: Bitdefender GravityZone version 7.1.2.33 and prior versions.
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 confidenceA link following (symlink) vulnerability in the EPAG component of Bitdefender Endpoint Security Tools for Windows allows a local attacker to cause denial of service by exploiting improper link resolution before file access. The attacker can create malicious symbolic links that the vulnerable EPAG component will follow, leading to system disruption.
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<= 7.1.2.33CVSS 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- Low
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:L/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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Check Bitdefender GravityZone versionOpen Bitdefender Central console or check the installed product version in Windows Programs and Features. Look for 'Bitdefender Endpoint Security Tools' or 'GravityZone' and note the exact version number displayed.Affected if The installed version is 7.1.2.33 or any lower version number.
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Identify EPAG component presenceCheck the Windows services list for the EPAG service or examine the Bitdefender installation directory (typically in Program Files or Program Files x86) for epag.exe or similar EPAG-related executable files.Affected if The EPAG component executable exists on the system.
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Verify symbolic link creation permissionsUse icacls or PowerShell to examine write permissions on common directories accessed by Windows services, particularly Temp folders and Bitdefender installation directories. Run: 'icacls %TEMP%' and check for permissions granted to non-admin users.Affected if Standard users have write permission to directories used by the EPAG service, allowing them to create symbolic links in those paths.
If the installed Bitdefender GravityZone version is 7.1.2.33 or earlier AND the EPAG component is present AND standard users can create symbolic links in directories accessed by EPAG, the environment is vulnerable to this CVE.
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 dataUpdate Bitdefender GravityZone to a version newer than 7.1.2.33 to obtain the patched EPAG component. As a temporary control, restrict local user permissions to prevent creation of symbolic links in directories accessed by the EPAG service.
- Consultation1.0 h
- Implementation2.0 h
- Testing2.0 h
- Review / QA1.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-3641 — 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-2021-3641 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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