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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 3 May 2022.
Windows 10 1507Operating system · Microsoft

CVE-2019-0803

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 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 in Windows when the Win32k component fails to properly handle objects in memory, aka 'Win32k Elevation of Privilege Vulnerability'. This CVE ID is unique from CVE-2019-0685, CVE-2019-0859.

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-2019-0803 is a local elevation of privilege vulnerability in Windows' Win32k.sys kernel component. The vulnerability stems from improper handling of memory objects, allowing a local authenticated attacker to execute arbitrary code in kernel mode and gain elevated privileges.

MitigationApply the Microsoft security update for CVE-2019-0803 via Windows Update or enterprise patch management systems to remediate the vulnerability.

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 1507Operating system
Affected:all versions
Windows 10 1607Operating system
Affected:all versions
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 7Operating system
Affected:all versions
Windows 8.1Operating 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. Identify the Windows version and build
    Run 'winver' from command prompt or check System Properties to see the exact Windows edition and build number (e.g., Windows 10 1809, Windows 7 SP1)
    Affected if The installed version matches any of: Windows 10 1507, 1607, 1703, 1709, 1803, 1809; Windows 7 any version; Windows 8.1 any version
  2. Check for installed security update
    Open Control Panel > Programs > View installed updates, or run 'wmic qfe list' command, and look for the CVE-2019-0803 patch (e.g., KB4493473 for Windows 7/8.1, KB4493441 for Windows 10)
    Affected if The security update for CVE-2019-0803 is NOT installed - the patch is absent from the system
  3. Verify Win32k.sys file version
    Navigate to C:\Windows\System32\drivers\win32k.sys, right-click > Properties > Details to view the file version, or run 'driverquery /v /fo list | findstr win32k'
    Affected if The win32k.sys version corresponds to an unpatched build (versions prior to the March 2019 security updates)

The system is vulnerable if it runs any affected Windows version (7, 8.1, or 10 1507-1809) AND lacks the CVE-2019-0803 security update.

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 for CVE-2019-0803 via Windows Update or enterprise patch management systems to remediate the vulnerability.

Recommended fix High confidence

Upgrade to the latest supported Windows version (Windows 10 21H2 or Windows 11) or to a currently supported Windows Server version for servers

  1. Open Windows Update on the affected system (Start > Settings > Update & Security > Windows Update)
  2. Click 'Check for updates' to download and install the latest security updates
  3. For Windows 7: Ensure update KB4493472 is installed (March 2019 Security Update)
  4. For Windows 8.1: Ensure update KB4493489 is installed (March 2019 Security Update)
  5. For Windows 10 versions 1507-1809: Ensure the March 2019 cumulative update (KB4493509 or corresponding update for your build) is installed
  6. Restart the system after updates are installed
  7. Verify the updates were successfully installed by checking Windows Update history
Caveat Windows 7 extended support ended January 2020; for continued security updates, upgrade to a supported OS version or enroll in Extended Security Updates (ESU) if available through volume licensing

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

Fix this in Windows 10 1507 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-2019-0803 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