CVE-2021-38086
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 · uneditedAcronis Cyber Protect 15 for Windows prior to build 27009 and Acronis Agent for Windows prior to build 26226 allowed local privilege escalation via DLL hijacking.
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 confidenceAcronis Cyber Protect 15 and Acronis Agent for Windows contain a DLL hijacking vulnerability allowing local privilege escalation. An attacker with low-privilege access can place a malicious DLL in a location from which the affected application loads DLLs, causing arbitrary code execution with elevated privileges.
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< 15= 15CVSS 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
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:N/UI:R/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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Verify Acronis product is installedCheck for Acronis Cyber Protect 15 or Acronis Agent for Windows in Programs and Features, or search for Acronis service entries in the Windows Services console (services.msc)Affected if Acronis Cyber Protect 15 or Acronis Agent for Windows is installed and running as a service
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Identify the installed version of Acronis Cyber Protect 15Open Registry Editor and navigate to HKLM\SOFTWARE\Acronis\Global\ or check the product UI under Help > About. The build number is displayed as a version identifier.Affected if The build number is below 27009 for Acronis Cyber Protect 15, or below 26226 for Acronis Agent for Windows
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Confirm the Acronis service runs with elevated privilegesOpen Services (services.msc), locate the Acronis service (e.g., Acronis Active Protection, Acronis Scheduler2), right-click and select Properties, and view the Log On accountAffected if The service runs under LocalSystem or another privileged account and the version is vulnerable
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Check for unauthorized DLLs in Acronis program directoriesInspect the Acronis installation directory (typically C:\Program Files\Acronis\) for unexpected or recently modified DLL files that do not belong to the productAffected if Unexpected DLL files are present in Acronis directories and the installed version is vulnerable
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Review ACLs on DLL load directoriesUse icacls or Explorer security properties to check if low-privilege users have Write permission on directories from which Acronis loads DLLs (e.g., program directories, system DLL locations)Affected if Users with low privileges can write to directories from which Acronis loads DLLs and the version is vulnerable
A user is affected if Acronis Cyber Protect 15 (build below 27009) or Acronis Agent for Windows (build below 26226) is installed and running with a service account that has elevated privileges, especially if the DLL search path is writable by low-privilege users.
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 · scoped15
Apply the vendor patches: update Acronis Cyber Protect 15 to build 27009 or later, and Acronis Agent for Windows to build 26226 or later.
Cyber Protect 15 build 27009+; Acronis Agent for Windows build 26226+
- 1. Identify the current build version of Acronis Cyber Protect 15 or Acronis Agent for Windows by checking About or version information in the product
- 2. For Cyber Protect 15: Upgrade to build 27009 or later
- 3. For Acronis Agent for Windows: Upgrade to build 26226 or later
- 4. Download the updated installer from the official Acronis download center or update server
- 5. Apply the update following standard Acronis update/upgrade procedures
- 6. Verify the new build version is installed correctly after the update
Generated from the published advisory — verify against the referenced sources before acting.
- Consultation2.0 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 $1,456.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-38086 — 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-2021-38086 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