CVE-2025-20161
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 software upgrade process of Cisco Nexus 3000 Series Switches and Cisco Nexus 9000 Series Switches in standalone NX-OS mode could allow an authenticated, local attacker with valid Administrator credentials to execute a command injection attack on the underlying operating system of an affected device. This vulnerability is due to insufficient validation of specific elements within a software image. An attacker could exploit this vulnerability by installing a crafted image. A successful exploit could allow the attacker to execute arbitrary commands on the underlying operating system with root privileges. Note: Administrators should validate the hash of any software image before installation.
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 confidenceThis is a command injection vulnerability in the software upgrade process of Cisco Nexus 3000 and 9000 Series Switches running NX-OS in standalone mode. The upgrade process fails to properly validate specific elements within a software image, allowing an authenticated attacker with Administrator credentials who can install a crafted image to execute arbitrary commands on the underlying OS with root privileges.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
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
- Low
- Integrity
- High
- Availability
- None
CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:L/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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Identify the Nexus modelRun 'show version' or 'show inventory' and confirm the device is a Nexus 3000 or 9000 Series SwitchAffected if The device model is NOT in the Nexus 3000 or 9000 series families
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Check NX-OS versionRun 'show version' and note the NX-OS release number displayed in the outputAffected if The installed NX-OS version matches any unpatched release that contains this vulnerability (compare against Cisco advisory for specific affected versions)
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Verify the system is in standalone modeRun 'show system mode' or check the running configuration for the mode setting. The vulnerability applies only to NX-OS running in standalone mode, not fabric modeAffected if The system is running in standalone mode (fabric mode is not affected)
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Review recent image installationsRun 'show install all history' to list recently installed software images and their installation timestampsAffected if Any untrusted or unrecognized software images appear in the installation history
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Audit Administrator accountsRun 'show user' and 'show running-config | include user' to list accounts with Administrator privilegesAffected if There are Administrator accounts that could install software images (the attacker needs these credentials to exploit the flaw)
Your environment is affected if you run a Nexus 3000 or 9000 Series Switch in standalone mode with NX-OS, where an authenticated Administrator could install a crafted software image.
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 dataAdministrators should validate the hash of any software image before installation and only use trusted, official Cisco images. Apply vendor patches when available.
- Consultation4.0 h
- Implementation6.0 h
- Testing3.0 h
- Review / QA2.0 h
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Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2025-20161 — 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-2025-20161 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
- No weaponised exploit code, or anything meant to cause harm
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