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Windows 10Operating system · Microsoft

CVE-2021-1701

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

A remote code execution vulnerability in the Windows Remote Procedure Call (RPC) Runtime component that allows attackers to execute arbitrary code by sending specially crafted RPC requests.

MitigationApply the relevant Microsoft security update for CVE-2021-1701 through Windows Update or patch management systems.

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. Check Windows version
    Run 'winver' or 'systeminfo | findstr /B /C:"OS Name" /C:"OS Version"' to identify the installed Windows version and build number
    Affected if The version matches any of the affected products: Windows 10 (all versions, 20h2, 1607, 1803, 1809, 1909, 2004), Windows 7 (all versions), Windows 8.1 (all versions), Windows RT 8.1 (all versions), Windows Server 2008 (all versions, R2), Windows Server 2012 (all versions, R2), Windows Server 2016 (a
  2. Verify RPC Runtime patch status
    Run 'wmic qfe list' or 'Get-HotFix | Sort-Object InstalledOn' to list installed security updates, then search for the CVE-2021-1701 update (typically KB4598223 or January 2021 Security Updates)
    Affected if The CVE-2021-1701 security update (January 2021 Security Update) is NOT installed on the system
  3. Confirm RPC service is running
    Run 'sc query rpcss' or check Services (RpcSs service) to verify the RPC Runtime service is active
    Affected if The RPC service (RpcSs) is running, exposing the RPC Runtime to network requests
  4. Check RPC network listening status
    Run 'netstat -an | findstr "135 139 445"' or use 'netsh interface tcp show global' to see if RPC endpoints are listening on network interfaces
    Affected if RPC endpoints are bound to accessible network interfaces (especially on servers or systems with exposed network services)

The system is affected if it runs any of the affected Windows versions listed AND lacks the CVE-2021-1701 security patch, with the RPC service exposed on the network.

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 relevant Microsoft security update for CVE-2021-1701 through Windows Update or patch management systems.

Fix this in Windows 10 Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing2.0 h
  • Review / QA1.0 h
6.0 hours of engineering $1,060
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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-2021-1701 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

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