Nx OsOperating system · Cisco
CVE-2021-1227
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 conduct a cross-site request forgery (CSRF) attack on an affected system. This vulnerability is due to insufficient CSRF protections for the NX-API on an affected device. An attacker could exploit this vulnerability by persuading a user of the NX-API to follow a malicious link. A successful exploit could allow the attacker to perform arbitrary actions with the privilege level of the affected user. The attacker could view and modify the device configuration. 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 confidenceCSRF vulnerability in Cisco NX-OS NX-API feature allows unauthenticated remote attackers to trick authenticated users into executing unintended API requests via malicious links. Successful exploitation grants the attacker arbitrary actions with the victim's privilege level, enabling viewing and modification of device configuration.
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
= 8.4\(2a\)= 8.4\(3\)= 8.4\(3\)s19= 9.3\(3\)idi9\(0.569\)= 7.3\(8\)n1\(0.809\)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
- None
- User interaction
- Required
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
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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Confirm NX-API is enabledRun 'show feature | include nxapi' or 'show running-config | include nxapi' to check if the NX-API feature is turned onAffected if NX-API feature is enabled (if disabled, the vulnerability cannot be exploited)
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Identify installed NX-OS versionRun 'show version' to display the installed NX-OS software versionAffected if The displayed version matches one of the affected versions: 8.4(2a), 8.4(3), 8.4(3)s19, 9.3(3)idi9(0.569), or 7.3(8)n1(0.809)
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Verify NX-API HTTP server statusRun 'show nxapi' to check if the NX-API HTTP server is listening and its configurationAffected if NX-API HTTP server is enabled and accepting requests
The device is affected if NX-API is enabled and the NX-OS version matches any of the listed affected versions (8.4(2a), 8.4(3), 8.4(3)s19, 9.3(3)idi9(0.569), or 7.3(8)n1(0.809)).
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 dataDisable NX-API if not required (it is disabled by default). If NX-API is necessary, implement proper CSRF token validation on the NX-API endpoint and educate users about not clicking untrusted links.
Fix this in Nx Os
Scoped from the published advisory
- Consultation2.0 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 $4,480.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2021-1227 — 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-2021-1227 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