CVE-2018-8344
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 · uneditedA remote code execution vulnerability exists when the Windows font library improperly handles specially crafted embedded fonts, aka "Microsoft Graphics Remote Code Execution Vulnerability." This affects Windows 7, Windows Server 2012 R2, Windows RT 8.1, Windows Server 2008, Windows Server 2012, Windows 8.1, Windows Server 2016, Windows Server 2008 R2, Windows 10, Windows 10 Servers.
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 confidenceA remote code execution vulnerability exists in the Windows font library due to improper handling of specially crafted embedded fonts. An attacker could exploit this by tricking a user into opening a file containing malicious embedded fonts, leading to arbitrary code execution with user 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 dataall versions= 1607= 1703= 1709= 1803all versionsall versionsall versionsall versions= r2all versions= r2all versions= 1709= 1803CVSS 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
- Network
- Complexity
- Low
- Privileges
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.0/AV:N/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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Check Windows versionRun 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify your Windows version and build numberAffected if Version is Windows 10 (any build), Windows 7 (any), Windows 8.1 (any), Windows RT 8.1 (any), Windows Server 2008/2008 R2 (any), Windows Server 2012/2012 R2 (any), or Windows Server 2016 (any build)
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Verify security update KB4343909 is installedOpen Control Panel > Programs and Features > View installed updates, or run 'wmic qfe list | findstr "4343909"' to check if the patch is presentAffected if The update KB4343909 is NOT installed on the system
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Confirm font driver service is runningOpen Services console (services.msc) and check if the 'Windows Font Cache Service' or 'Font Driver Host' (fontdrvhost.exe) is active, or run 'tasklist | findstr fontdrvhost'Affected if The font driver host process is running (this is the vulnerable component that processes embedded fonts)
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Identify files with embedded fontsSearch for common file types that support embedded fonts: .docx, .xlsx, .pptx, .pdf, .ttf, .otf files. Use 'Get-ChildItem -Recurse -Include *.docx,*.xlsx,*.pptx,*.pdf,*.ttf,*.otf' in PowerShell to enumerateAffected if Users have opened or could open untrusted documents containing embedded fonts from unknown sources
A system is likely affected if it runs any of the listed Windows versions AND lacks security update KB4343909 AND users may open untrusted documents with embedded fonts.
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.
From vendor dataApply the Microsoft security update (KB4343909 or subsequent relevant patches) to affected Windows systems to remediate the font library vulnerability.
- Consultation3.0 h
- Implementation6.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,224.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-8344 — 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-2018-8344 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
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