CVE-2023-21683
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 Internet Key Exchange (IKE) Extension Denial of Service 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 denial of service vulnerability in Windows Internet Key Exchange (IKE) Extension, which handles key negotiation for IPsec VPN connections. An unauthenticated remote attacker could send specially crafted IKE packets to cause the affected system to stop responding, leading to service disruption.
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 versionsall versionsall versionsall 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
- None
- Scope
- Unchanged
- Confidentiality
- None
- Integrity
- None
- Availability
- High
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 the installed Windows version and build numberAffected if The version is Windows 10 1607, 1809, 20h2, 21h2, or 22h2; Windows 11 21h2 or 22h2; or Windows 8.1
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Verify IKE Extension service is presentRun 'Get-Service IKEEXT' in PowerShell or check Services.msc for 'IKE and AuthIP IPsec Keying Modules'Affected if The IKEEXT service exists on the system (vulnerable code path is present)
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Confirm IPsec VPN is configured or activeRun 'Get-NetIPsecPhase1AuthSet' in PowerShell or check for active IPsec policies via 'netsh ipsec dynamic show all'Affected if IPsec VPN policies, tunnels, or IKE connections are configured on the host
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Check network exposure of IKE portsRun 'netsh advfirewall firewall show rule name=all' or scan for UDP ports 500 and 4500 being accessible from untrusted networksAffected if UDP ports 500 (IKE) and 4500 (NAT-T) are open to untrusted networks, indicating direct internet exposure or VPN gateway role
A system is affected if it runs a vulnerable Windows version listed above, has the IKEEXT service, and has IPsec VPN functionality enabled with network accessibility to IKE ports.
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 addressing CVE-2023-21683. Organizations should prioritize patching systems with direct internet exposure or those acting as VPN gateways, and test IPsec VPN functionality after applying the patch.
- Consultation4.0 h
- Implementation3.0 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 $3,680.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2023-21683 — 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-2023-21683 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