Nx OsOperating system · Cisco
CVE-2019-1968
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 · uneditedA vulnerability in the NX-API feature of Cisco NX-OS Software could allow an unauthenticated, remote attacker to cause an NX-API system process to unexpectedly restart. The vulnerability is due to incorrect validation of the HTTP header of a request that is sent to the NX-API. An attacker could exploit this vulnerability by sending a crafted HTTP request to the NX-API on an affected device. A successful exploit could allow the attacker to cause a denial of service (DoS) condition in the NX-API service; however, the NX-OS device itself would still be available and passing network traffic. Note: The NX-API feature is disabled by default.
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 · high confidenceThe vulnerability exists in the NX-API feature of Cisco NX-OS Software. An unauthenticated remote attacker can send a crafted HTTP request with malformed headers to the NX-API endpoint, triggering incorrect validation that causes the NX-API system process to unexpectedly restart, resulting in denial of service for the NX-API service while the underlying device continues passing network traffic.
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
Nx OsOperating system
= 7.3= 8.1= 8.2= 8.3= 6.1\(2\)i2= 6.1\(2\)i3= 7.0\(3\)i4= 7.0\(3\)i7= 9.2= 6.0\(2\)a8= 7.0\(3\)f= 7.1CVSS 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 NX-OS versionRun 'show version' on the device CLI and locate the 'NXOS' version lineAffected if The version matches one of: 7.3, 8.1, 8.2, 8.3, 6.1(2)i2, 6.1(2)i3, 7.0(3)i4, 7.0(3)i7, 9.2, 6.0(2)a8, 7.0(3)f, or 7.1
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Verify NX-API feature statusRun 'show feature | include nxapi' or 'show running-config | include nxapi' to check if the NX-API feature is enabledAffected if The output shows nxapi as enabled or 'feature nxapi' is present in the running configuration
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Confirm NX-API is accessible over HTTP/HTTPSAttempt to reach the NX-API endpoint (typically port 80/443) or verify the HTTP server configuration with 'show running-config | include http'Affected if The NX-API HTTP service is listening and reachable (even if authentication would be required for legitimate use)
You are affected if your NX-OS version matches the listed affected versions AND the NX-API feature is enabled on your device.
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 Cisco patch for CVE-2019-1968 to affected NX-OS devices. Until patched, ensure NX-API remains disabled (default state) or restrict access to trusted management networks only.
Fix this in Nx Os
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 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 $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-1968 — 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-2019-1968 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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- Version or environment caveats, and links to real fixes
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