Nx OsOperating system · Cisco
CVE-2019-1730
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 Bash shell implementation for Cisco NX-OS Software could allow an authenticated, local attacker to bypass the limited command set of the restricted Guest Shell and execute commands at the privilege level of a network-admin user outside of the Guest Shell. The attacker must authenticate with valid administrator device credentials. The vulnerability is due to the incorrect implementation of a CLI command that allows a Bash command to be incorrectly invoked on the Guest Shell CLI. An attacker could exploit this vulnerability by authenticating to the device and entering a crafted command at the Guest Shell prompt. A successful exploit could allow the attacker to issue commands that should be restricted by a Guest Shell account.
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 allows an authenticated attacker with valid administrator credentials to escape the restricted Guest Shell sandbox in Cisco NX-OS and execute commands at full network-admin privilege level. The root cause is an incorrectly implemented CLI command that permits Bash commands to be invoked from the Guest Shell prompt, bypassing the intended access restrictions.
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
>= 7.0\(3\)i4, < 7.0\(3\)i4\(9\)>= 7.0\(3\)i7, < 7.0\(3\)i7\(4\)>= 8.1, < 8.3\(1\)>= 7.0\(3\), < 7.0\(3\)f3\(5\)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
- Local
- Complexity
- Low
- Privileges
- High
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- High
- Availability
- High
CVSS:3.1/AV:L/AC:L/PR:H/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 checksWork through these to decide whether this CVE applies to you.
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Check Cisco NX-OS versionRun 'show version' command on the switch to obtain the installed NX-OS software versionAffected if The version falls within any of these ranges: 7.0(3)i4 through 7.0(3)i4(8), 7.0(3)i7 through 7.0(3)i7(3), 8.1 through 8.3(0), or 7.0(3) through 7.0(3)f3(4)
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Verify Guest Shell feature statusRun 'show feature | include guestshell' to see if the Guest Shell feature is enabledAffected if Guest Shell is enabled (feature is active)
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Confirm administrator account existenceRun 'show user account' or check AAA configuration to verify administrator-level accounts exist on the deviceAffected if Any administrator-level accounts are configured on the switch
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Check for vulnerable command availabilityFrom Guest Shell prompt, attempt to run 'run bash' or observe if the CLI permits Bash command invocation from within the sandboxAffected if Bash commands can be executed from within the Guest Shell environment, indicating the vulnerability is present
Your environment is affected if the NX-OS version is within the affected ranges listed and Guest Shell is enabled with administrator accounts present on the 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 data7.08.3
Apply the Cisco NX-OS software update that addresses this vulnerability; restrict and carefully manage administrator credentials as an interim compensating control.
Fix this in Nx Os
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing6.0 h
- Review / QA4.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $6,176.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2019-1730 — 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-2019-1730 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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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
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