CVE-2018-8305
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 · uneditedAn information disclosure vulnerability exists in Windows Mail Client when a message is opened, aka "Windows Mail Client Information Disclosure Vulnerability." This affects Mail, Calendar, and People in Windows 8.1 App Store.
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 confidenceAn information disclosure vulnerability exists in the Windows Mail Client for Windows 8.1 App Store (affecting Mail, Calendar, and People apps). When a message is opened, sensitive information may be exposed to unauthorized users. The CVSS 6.5 indicates network-exploitable access with low complexity and no authentication required.
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 versionsall versionsall versionsCVSS 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
- None
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:N
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 Windows 8.1 is runningOpen Command Prompt or PowerShell and run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"'. Alternatively, press Win+R, type 'winver', and press Enter.Affected if The system is running Windows 8.1 (any version) - other Windows versions are not affected by this specific Store app vulnerability.
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Identify installed Windows Store appsOpen PowerShell and run 'Get-AppxPackage -Name *mail*' and 'Get-AppxPackage -Name *calendar*' and 'Get-AppxPackage -Name *people*' to list installed versions of these apps.Affected if The Windows Store versions of Mail, Calendar, or People apps are installed (these are separate from the desktop mail app included in Outlook). The vulnerability affects the App Store versions only.
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Confirm the app is from the StoreExamine the output from the Get-AppxPackage command. The PackageFullName will contain 'WindowsStore' or similar, indicating it is a Windows Store (UWP) application versus a traditional desktop application.Affected if The installed apps are from the Windows Store (UWP/APPX packages) as indicated by the package metadata. Traditional desktop email clients are not affected by this specific CVE.
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Check for recent security updatesOpen Control Panel > Programs and Features > View installed updates, or run 'Get-HotFix | Where-Object {$_.Description -eq "Security Update"}' in PowerShell. Look for KB4457044 or subsequent patches.Affected if KB4457044 or a later security update for Windows 8.1 Store apps has NOT been installed - the system remains vulnerable.
You are affected if you are running Windows 8.1 and have the Windows Store versions of Mail, Calendar, or People apps installed without the KB4457044 or later security patch applied.
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 vendor security update for Windows 8.1 Store apps (KB4457044 or subsequent patches). Until patched, avoid opening untrusted messages and restrict network access to trusted sources only.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-8305 — 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-2018-8305 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