Fabric Operating SystemOperating system · Broadcom

CVE-2018-6438

HIGH · 7.8 CVSS v3.0 Published 2018-11-08
Fix available
A fix is available. Upgrade to 7.4.2d / 8.0.2f or later.
See remediation →
80/100
Remediation priority · High
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 supportsave command of Brocade Fabric OS command line interface (CLI) versions before 8.2.1, 8.1.2f, 8.0.2f, 7.4.2d could allow a local attacker to escape the restricted shell and, gain root access.

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 confidence

A local privilege escalation vulnerability exists in Brocade Fabric OS CLI where the supportsave command lacks proper validation, allowing an authenticated local attacker to escape the restricted shell (rbash) and execute commands as root. The attacker requires CLI access but can escalate from a restricted user account to full root privileges.

MitigationUpgrade Brocade Fabric OS to version 8.2.1, 8.1.2f, 8.0.2f, or 7.4.2d or later. Restrict CLI access to trusted personnel and monitor for unauthorized access attempts.

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
Fabric Operating SystemOperating system
Affected:>= 7.4.2, < 7.4.2d>= 8.0.2, < 8.0.2f>= 8.1.2, < 8.1.2f>= 8.2.0, < 8.2.1

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
Low
User interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:L/AC:L/PR:L/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. Check Fabric OS version
    Log into the Fabric OS CLI and run the command to display the firmware version (typically 'version' or 'firmwaresw'). Compare the displayed version against the affected ranges: 7.4.2 to 7.4.2c, 8.0.2 to 8.0.2e, 8.1.2 to 8.1.2e, or 8.2.0.
    Affected if The installed version falls within any of the listed version ranges.
  2. Identify CLI user accounts
    Review the list of configured local user accounts on the switch using the CLI user management commands (such as 'userconfig --show' or similar). Note which accounts have restricted or limited shell access.
    Affected if There are user accounts with CLI access beyond trusted administrative personnel.
  3. Verify supportsave command access
    As a restricted (non-root) user with CLI access, attempt to invoke the supportsave command or check its availability in the command help/usage listings.
    Affected if The supportsave command is accessible to authenticated non-privileged users.
  4. Confirm rbash restriction is in place
    As a restricted user, verify that the shell is operating in restricted mode (rbash) by attempting a simple command escape (e.g., running 'cd /' or using pipe operators to external binaries).
    Affected if The restricted user session appears to enforce rbash but may have the vulnerability that allows escape.

Your environment is affected if the Fabric OS version falls within the vulnerable ranges AND non-administrative users have CLI access to the supportsave command.

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
Upgrade available Upgrade to 7.4.2d / 8.0.2f / 8.1.2f or later
Fixed in 7.4.2d8.0.2f8.1.2f
Interim mitigation

Upgrade Brocade Fabric OS to version 8.2.1, 8.1.2f, 8.0.2f, or 7.4.2d or later. Restrict CLI access to trusted personnel and monitor for unauthorized access attempts.

Fix this in Fabric Operating System Scoped from the published advisory
  • Consultation2.0 h
  • Implementation3.0 h
  • Testing4.0 h
  • Review / QA2.0 h
11.0 hours of engineering $1,900
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Scan for this in your stack

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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-2018-6438 in production — separate from our analysis above.

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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
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  • Version or environment caveats, and links to real fixes
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