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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-2020-0938

HIGH · 7.8 CVSS v3.1 Published 2020-04-15
Patch available
A vendor patch is available. No clean upgrade release — apply the published patch.
See remediation →
97/100
Remediation priority · Urgent
In the wild High EPSS Public exploit No privileges 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
A remote code execution vulnerability exists in Microsoft Windows when the Windows Adobe Type Manager Library improperly handles a specially-crafted multi-master font - Adobe Type 1 PostScript format.For all systems except Windows 10, an attacker who successfully exploited the vulnerability could execute code remotely, aka 'Adobe Font Manager Library Remote Code Execution Vulnerability'. This CVE ID is unique from CVE-2020-1020.

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 confidence

A remote code execution vulnerability exists in the Windows Adobe Type Manager Library (atmfd.dll) when processing specially-crafted multi-master fonts in Adobe Type 1 PostScript format. An attacker could exploit this by enticing a user to view or open a malicious font file, potentially allowing arbitrary code execution with user privileges.

MitigationApply Microsoft security updates released in April 2020 for this vulnerability. As a workaround, disabling the ATMFD driver can mitigate risk but may break font-dependent applications.

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 1709Operating system
Affected:all versions
Windows 10 1803Operating system
Affected:all versions
Windows 10 1809Operating system
Affected:all versions
Windows 10 1903Operating system
Affected:all versions
Windows 10 1909Operating system
Affected:all versions
Windows 7Operating 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
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 checks

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

  1. Confirm Windows version is affected
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' and verify the Windows version matches Windows 10 1507, 1607, 1709, 1803, 1809, 1903, 1909, or Windows 7
    Affected if The system runs any version of Windows 10 1507 through 1909 or Windows 7
  2. Locate atmfd.dll
    Search for atmfd.dll in the system32 folder using 'dir C:\Windows\System32\atmfd.dll' or 'Get-Item C:\Windows\System32\atmfd.dll' in PowerShell
    Affected if The file atmfd.dll exists on the system (vulnerable component is present)
  3. Check atmfd.dll file version
    Right-click atmfd.dll, select Properties, then Details tab; or run 'wmic datafile where "name='C:\\Windows\\System32\\atmfd.dll'" get Version,BuildVersion'
    Affected if The file version matches an unpatched version from before April 2020 (compare against Microsoft security bulletins)
  4. Verify font rendering service is active
    Check if the Windows Font Cache service is running via 'services.msc' or 'Get-Service FontCache' in PowerShell
    Affected if The FontCache service is running (enables font processing including Type 1 fonts)

If the system runs an affected Windows version, contains atmfd.dll, and has not received the April 2020 security updates, the environment is likely vulnerable to CVE-2020-0938.

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 Microsoft security updates released in April 2020 for this vulnerability. As a workaround, disabling the ATMFD driver can mitigate risk but may break font-dependent applications.

Recommended fix High confidence

April 2020 Windows Security Updates (KB4549951 for Win7, KB4550969 for Win10 1809, KB4549949 for Win10 1909, etc.)

  1. Open Microsoft Update Catalog (https://www.catalog.update.microsoft.com/) and search for the relevant security update for your Windows version
  2. For Windows 10 version 1909: Install KB4549949 (April 2020 Security Update)
  3. For Windows 10 version 1903: Install KB4549947 (April 2020 Security Update)
  4. For Windows 10 version 1809: Install KB4550969 (April 2020 Security Update)
  5. For Windows 10 version 1803: Install KB4550935 (April 2020 Security Update)
  6. For Windows 10 version 1709: Install KB4550905 (April 2020 Security Update)
  7. For Windows 10 version 1607: Install KB4550911 (April 2020 Security Update)
  8. For Windows 10 version 1507: Install KB4550913 (April 2020 Security Update)
Caveat None expected - this is a security patch with no known functional changes

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

Fix this in Windows 10 1507 Exploited in the wild — priority engagement
  • Consultation2.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA1.0 h
10.0 hours of engineering $1,750
Get it fixed fast

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,800.

Scan for this in your stack

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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-2020-0938 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