Enterprise Network Function Virtualization InfrastructureApplication · Cisco
CVE-2020-3236
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 CLI of Cisco Enterprise NFV Infrastructure Software (NFVIS) could allow an authenticated, local attacker to gain root shell access to the underlying operating system and overwrite or read arbitrary files. The attacker would need valid administrative credentials. This vulnerability is due to improper input validation of CLI command arguments. An attacker could exploit this vulnerability by using path traversal techniques when executing a vulnerable command. A successful exploit could allow the attacker to gain root shell access to the underlying operating system and overwrite or read arbitrary files on an affected device.
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 confidenceCisco Enterprise NFV Infrastructure Software (NFVIS) contains a CLI command injection vulnerability due to improper input validation. An authenticated attacker with administrative credentials can exploit this by using path traversal techniques (e.g., ../../../') within vulnerable CLI commands. This allows the attacker to break out of intended command boundaries, gain root shell access to the underlying Linux OS, and read/write arbitrary files on the affected device.
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
Enterprise Network Function Virtualization InfrastructureApplication
< 4.1.1CVSS 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
- 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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Confirm NFVIS installationIdentify if Cisco Enterprise NFV Infrastructure Software is installed by running 'show version' or checking for NFVIS processes/process name in the systemAffected if NFVIS is present on the system
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Check NFVIS versionRun the command 'show version' in the NFVIS CLI to retrieve the installed software version, then compare it to the affected range (versions prior to 4.1.1)Affected if Installed version is below 4.1.1
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Verify CLI administrative access existsConfirm that administrative/root-level CLI access is configured and accessible - check for enabled admin accounts and CLI access methodsAffected if Administrative CLI access is enabled and reachable (this is required for the vulnerability to be exploitable)
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Inspect for unauthorized root shell accessCheck system logs and shell history files for signs of unexpected root shell spawns or commands breaking out of CLI context (look for '/bin/sh', '/bin/bash', or shell escape patterns in logs)
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Review for suspicious file accessExamine system logs and audit trails for unusual file read/write operations, especially outside the expected NFVIS directory structure, using commands like 'grep' on auth logs or reviewing bash historyAffected if Unexpected file access or directory traversal patterns (../../) appear in logs
You are affected if NFVIS is installed with a version prior to 4.1.1 AND administrative CLI access is enabled and reachable, regardless of whether you observe exploitation evidence.
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 data4.1.1
Apply the Cisco patch for CVE-2020-3236 which addresses the input validation flaw in NFVIS CLI commands. Restrict administrative access to trusted personnel and monitor for unauthorized root-level access attempts.
Fix this in Enterprise Network Function Virtualization Infrastructure
Scoped from the published advisory
- Consultation2.0 h
- Implementation3.0 h
- Testing2.0 h
- Review / QA1.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,272.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2020-3236 — 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-2020-3236 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
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