CVE-2021-1702
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 · uneditedWindows Remote Procedure Call Runtime Elevation of Privilege Vulnerability
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 confidenceThis is a local elevation of privilege vulnerability in the Windows Remote Procedure Call (RPC) Runtime component. An authenticated attacker could exploit this to execute arbitrary code with elevated privileges, potentially gaining SYSTEM-level access on the affected system.
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= 20h2= 1607= 1803= 1809= 1909= 2004all versionsall versionsall versionsall versions= r2all versions= r2all versions= 20h2= 1909= 2004all 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
- 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 checksWork through these to decide whether this CVE applies to you.
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Identify Windows version and build numberRun `winver` or `systeminfo | findstr /B /C:"OS Name" /C:"OS Version"` to display the installed Windows version and build numberAffected if The version displayed matches any of the affected versions: Windows 10 (20h2, 1607, 1803, 1809, 1909, 2004), Windows 7, Windows 8.1, Windows Rt 8.1, Windows Server 2008, 2008 R2, 2012, 2012 R2, 2016, 2019, or any version of these products listed as 'all versions'
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Confirm the security update is installedOpen Control Panel > Programs > Programs and Features > View installed updates, or run `Get-HotFix` in PowerShell to list installed security patchesAffected if The specific security update for CVE-2021-1702 (January 2021 Patch Tuesday) is NOT installed - the system remains vulnerable until the update is applied
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Verify RPC Runtime component versionCheck the RPC Runtime DLL version. Open File Explorer, navigate to C:\Windows\System32\rpcrt4.dll, right-click > Properties > Details to view the file versionAffected if The file version is older than the patched version corresponding to the January 2021 security update for your Windows version
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Check RPC service statusOpen Services (services.msc) or run `sc query rpcss` to verify the RPC Endpoint Mapper service is runningAffected if The RPC service is running (default state) - combined with an unpatched version, this means the attack surface is present
The system is affected if it runs any version of Windows 10, 7, 8.1, Rt 8.1, Server 2008, 2008 R2, 2012, 2012 R2, 2016, or 2019 AND lacks the January 2021 security update for CVE-2021-1702.
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 for CVE-2021-1702, which addresses the RPC Runtime vulnerability through the standard Windows Update process or by deploying the applicable KB patch to all affected Windows systems.
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1702 — 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-2021-1702 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