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Windows 10Operating system · Microsoft

CVE-2021-1700

HIGH · 8.8 CVSS v3.1 Published 2021-01-12
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
94/100
Remediation priority · Urgent
Remotely reachable Zero-click

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
Remote Procedure Call Runtime Remote Code Execution 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 confidence

CVE-2021-1700 is a Remote Procedure Call (RPC) Runtime vulnerability that allows remote attackers to execute arbitrary code on affected Windows systems. The vulnerability exists in the Windows RPC Runtime component and can be exploited without authentication in low-complexity attacks.

MitigationApply the Microsoft security updates for CVE-2021-1700 to all affected Windows systems. Prioritize critical infrastructure and externally-facing systems given the remote exploitation vector and high CVSS score.

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 10Operating system
Affected:all versions= 20h2= 1607= 1803= 1809= 1909= 2004
Windows 7Operating system
Affected:all versions
Windows 8.1Operating system
Affected:all versions
Windows Rt 8.1Operating system
Affected:all versions
Windows Server 2008Operating system
Affected:all versions= r2
Windows Server 2012Operating system
Affected:all versions= r2
Windows Server 2016Operating system
Affected:all versions= 20h2= 1909= 2004
Windows Server 2019Operating 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
Network
Complexity
Low
Privileges
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/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 Windows version and build number
    Open Command Prompt or PowerShell and run 'winver' or execute 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to display the installed Windows edition, version, and build number
    Affected if The system runs an unpatched Windows 10 version (1607, 1803, 1809, 1909, 2004, or 20h2), Windows 7 any version, Windows 8.1 any version, Windows Server 2008 any version, Windows Server 2012 any version, Windows Server 2016 any version, or Windows Server 2019 any version, and the security update is n
  2. Verify RPC Runtime component presence
    Confirm the RPC Runtime is available by checking that the system is a supported Windows installation. The RPC Runtime (RpcRtRemote.dll or similar) is included by default in all affected Windows versions listed
    Affected if The system runs any of the affected Windows versions listed in the first check and is therefore using a vulnerable version of the RPC Runtime component
  3. Check for installed security update
    Open Control Panel > Programs > Programs and Features > View installed updates, or run 'Get-HotFix | Where-Object {$_.Description -like "Security Update"}' in PowerShell, and look for the January 2021 security update for CVE-2021-1700
    Affected if The specific security update for CVE-2021-1700 (January 2021 Patch Tuesday) is NOT installed on the system, meaning the RPC Runtime vulnerability remains unpatched
  4. Confirm RPC service is enabled
    Verify the RPC service is running by opening Services console (services.msc) and locating 'Remote Procedure Call (RPC)' and 'RPC Endpoint Mapper', or run 'Get-ServiceRpc*' in PowerShell
    Affected if The RPC service is running and exposed, which is the default configuration on Windows systems, making the vulnerability exploitable if the system is unpatched

A system is affected if it runs any of the listed Windows versions and does not have the January 2021 security update for CVE-2021-1700 installed, with the RPC service enabled (default state).

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.

From vendor data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Microsoft security updates for CVE-2021-1700 to all affected Windows systems. Prioritize critical infrastructure and externally-facing systems given the remote exploitation vector and high CVSS score.

Fix this in Windows 10 Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing6.0 h
  • Review / QA2.0 h
20.0 hours of engineering $3,500
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-1700 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

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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-2021-1700 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