Unified Computing SystemApplication · Cisco

CVE-2017-12255

MEDIUM · 6.7 CVSS v3.0 Published 2017-09-21
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
69/100
Remediation priority · Elevated
Zero-click

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 · unedited
A vulnerability in the CLI of Cisco UCS Central Software could allow an authenticated, local attacker to gain shell access. The vulnerability is due to insufficient input validation of commands entered in the CLI, aka a Restricted Shell Break Vulnerability. An attacker could exploit this vulnerability by entering a specific command with crafted arguments. An exploit could allow the attacker to gain shell access to the underlying system. Cisco Bug IDs: CSCve70762.

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 · moderate confidence

A vulnerability in the Cisco UCS Central Software CLI allows an authenticated local attacker to escape the restricted shell and gain full shell access to the underlying system. The vulnerability stems from insufficient input validation of CLI commands, where specific commands with crafted arguments can bypass the restricted shell sandbox.

MitigationApply the Cisco patch for bug CSCve70762 when released. Until then, restrict local CLI access to trusted administrators only and monitor for signs of unauthorized shell access.

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
Unified Computing SystemApplication
Affected:= 1.5\(1c\)

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:3.0/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 checks

Work through these to decide whether this CVE applies to you.

  1. Identify Cisco UCS Central version
    Access the CLI and run the command to display the system version (typically 'show version' or similar UCS Central CLI command)
    Affected if version displayed is exactly 1.5(1c)
  2. Confirm product is Cisco UCS Central
    Verify the system is running Cisco UCS Central Software, not another Cisco product, by checking the system prompt or version output
    Affected if product is Cisco UCS Central and version is 1.5(1c)
  3. Check for local CLI accounts
    Review user accounts with local CLI access permissions in the UCS Central management interface
    Affected if local authenticated users exist with CLI access
  4. Audit for shell escape evidence
    Review CLI command history or system logs for commands that attempt to bypass restricted shell restrictions or spawn unexpected shell sessions

A system is affected if it runs Cisco UCS Central version 1.5(1c) and has local CLI accounts with authenticated access, as the vulnerability allows escape from the restricted shell via specially crafted CLI command arguments.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

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 data
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Apply the Cisco patch for bug CSCve70762 when released. Until then, restrict local CLI access to trusted administrators only and monitor for signs of unauthorized shell access.

Fix this in Unified Computing System Scoped from the published advisory
  • Consultation4.0 h
  • Implementation2.0 h
  • Testing6.0 h
  • Review / QA2.0 h
14.0 hours of engineering $2,420
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Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2017-12255 — 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 sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2017-12255 in production — separate from our analysis above.

No notes yet

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What this is

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.

What belongs here
  • 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