CVE-2021-44204
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 · uneditedLocal privilege escalation via named pipe due to improper access control checks. The following products are affected: Acronis Cyber Protect 15 (Windows) before build 28035, Acronis Agent (Windows) before build 27147, Acronis Cyber Protect Home Office (Windows) before build 39612, Acronis True Image 2021 (Windows) before build 39287
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 · high confidenceLocal privilege escalation vulnerability in Acronis Windows products where improper access control checks on named pipes allow a low-privileged local authenticated attacker to gain SYSTEM-level privileges. The vulnerability stems from the Acronis services creating named pipes without adequate security restrictions, enabling token impersonation or manipulation attacks.
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= 2021< c21.06= 15all 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
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/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 Acronis productsOpen Control Panel > Programs and Features, or run 'Get-ItemProperty HKLM:\Software\Microsoft\Windows\CurrentVersion\Uninstall\* | Select-Object DisplayName, DisplayVersion' to list installed software and look for Acronis products such as True Image, Agent, Cyber Protect, or Cyber Protect Home Office.Affected if Any Acronis product from the affected list is present (True Image 2021, Acronis Agent version below c21.06, Cyber Protect 15, or Cyber Protect Home Office any version).
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Verify Acronis service statusOpen Services (services.msc) or run 'Get-Service | Where-Object {$_.DisplayName -like "*Acronis*"}' to check if any Acronis services are currently running on the system.Affected if Acronis services are running, which exposes the named pipe attack surface.
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Check version against affected rangesCompare the installed Acronis product version to the affected ranges: True Image version 2021 is affected; Acronis Agent versions below build c21.06 (below 27147) are affected; Cyber Protect version 15 is affected; Cyber Protect Home Office all versions are affected.Affected if The installed version falls within the affected ranges specified in the CVE.
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Confirm low-privileged user contextRun 'whoami /groups' or check local user group membership to verify the current user is not an administrator. The vulnerability specifically affects low-privileged authenticated local users.Affected if The current user has limited (non-administrator) privileges but has authenticated local access to the system.
A user is affected if they have any Acronis product from the affected list installed, the product version falls within the vulnerable range, Acronis services are running, and the user has authenticated local access to the system as a low-privileged user.
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 · scopedUpdate affected Acronis products to the specified fixed builds: Cyber Protect 15 to build 28035+, Acronis Agent to build 27147+, Cyber Protect Home Office to build 39612+, and True Image 2021 to build 39287+. Alternatively, restrict local user permissions and monitor for suspicious pipe interactions.
Acronis Cyber Protect 15 build 28035+; Acronis Agent build 27147+; Acronis Cyber Protect Home Office build 39612+; Acronis True Image 2021 build 39287+
- 1. Identify the currently installed Acronis product and its exact build version
- 2. For Acronis Cyber Protect 15 users: Upgrade to build 28035 or later
- 3. For Acronis Agent users: Upgrade to build 27147 or later
- 4. For Acronis Cyber Protect Home Office users: Upgrade to build 39612 or later
- 5. For Acronis True Image 2021 users: Upgrade to build 39287 or later
- 6. Verify the installed build version after upgrade to confirm the patch was applied
- 7. Test the named pipe functionality to ensure normal operation after the update
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation4.0 h
- Implementation2.0 h
- Testing8.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-44204 — 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-2021-44204 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