CVE-2018-6437
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 help 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 confidenceA local privilege escalation vulnerability exists in Brocade Fabric OS CLI where the help command can be exploited to escape the restricted shell (rbash) and gain root access. This allows a local authenticated attacker with limited CLI privileges to escalate to full root privileges on the underlying operating system.
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>= 7.4.2, < 7.4.2d>= 8.0.2, < 8.0.2f>= 8.1.2, < 8.1.2f>= 8.2.0, < 8.2.1CVSS 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
- 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 checksWork through these to decide whether this CVE applies to you.
-
Identify Fabric OS versionRun 'version' or 'firmwareShow' command in the Fabric OS CLI to retrieve the installed OS version.Affected if The version falls within any of these ranges: 7.4.2 to 7.4.2d (exclusive), 8.0.2 to 8.0.2f (exclusive), 8.1.2 to 8.1.2f (exclusive), or 8.2.0 to 8.2.1 (exclusive).
-
Confirm restricted shell is enforcedCheck if the current shell is rbash by examining the shell environment or attempting to run commands outside allowed paths. In Fabric OS, limited users typically operate within a restricted shell.Affected if The user session operates under rbash or another restricted shell environment, which the help command escape targets.
-
Verify user privilege levelRun 'userConfig -show' or 'roleShow' (if available) to identify the current user's role and permissions. Low-privilege accounts such as 'user' or 'operator' roles are vulnerable.Affected if The account has limited CLI privileges (not admin/root) but has CLI access, making it a candidate for privilege escalation.
-
Test help command behaviorIn the restricted CLI shell, run the help command followed by shell escape sequences (e.g., 'help !/bin/sh' or similar rbash escape techniques documented for this CVE).Affected if The help command permits shell escape or bypasses rbash restrictions, allowing execution of arbitrary commands.
If the Fabric OS version is within any affected range AND the user has limited CLI access within a restricted shell, the environment is vulnerable to privilege escalation via the help command escape.
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 data7.4.2d8.0.2f8.1.2f
Upgrade Brocade Fabric OS to version 8.2.1 or later (or 8.1.2f, 8.0.2f, 7.4.2d respectively) to remediate this vulnerability. If upgrades cannot be immediately performed, limit local CLI access to trusted personnel only.
- Consultation4.0 h
- Implementation4.0 h
- Testing4.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,968.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2018-6437 — 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-2018-6437 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
Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.
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
- No spam, self-promotion, credentials, or personal data