dbcve.org
Mds 9000 Nx OsApplication · Cisco

CVE-2017-6655

MEDIUM · 6.5 CVSS v3.1 Published 2017-06-13
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
70/100
Remediation priority · Elevated
No privileges 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 Fibre Channel over Ethernet (FCoE) protocol implementation in Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a denial of service (DoS) condition when an FCoE-related process unexpectedly reloads. This vulnerability affects Cisco NX-OS Software on the following Cisco devices when they are configured for FCoE: Multilayer Director Switches, Nexus 7000 Series Switches, Nexus 7700 Series Switches. More Information: CSCvc91729. Known Affected Releases: 8.3(0)CV(0.833). Known Fixed Releases: 8.3(0)ISH(0.62) 8.3(0)CV(0.944) 8.1(1) 8.1(0.8)S0 7.3(2)D1(0.47).

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 denial of service vulnerability exists in the Fibre Channel over Ethernet (FCoE) protocol implementation in Cisco NX-OS Software. An unauthenticated, adjacent attacker on the same network segment can send malicious FCoE traffic that causes the FCoE-related process to unexpectedly reload, resulting in service disruption. This affects Nexus 7000/7700 Series Switches and Multilayer Director Switches when configured for FCoE.

MitigationUpgrade Cisco NX-OS Software to a fixed release (8.3(0)CV(0.944), 8.3(0)ISH(0.62), 8.1(1), or later). If upgrade is not immediately feasible, consider disabling FCoE or implementing network segmentation controls to limit adjacent attacker 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
Mds 9000 Nx OsApplication
Affected:= 7.3\(1\)d1\(1\)
Nx Os For Nexus 5500 Platform SwitchesApplication
Affected:= 7.3\(1\)n1\(1\)
Nx Os For Nexus 5600 Platform SwitchesApplication
Affected:= 7.3\(1\)n1\(1\)
Nx Os For Nexus 7700 Series SwitchesApplication
Affected:= 8.0\(1\)\(ed\)
Nx OsOperating system
Affected:= 8.0\(1\)s2= 8.3\(0\)cv\(0.833\)

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
Adjacent
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/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 the NX-OS software version
    Execute 'show version' on the device CLI and locate the 'NX-OS' or 'system:' version line
    Affected if The version shown matches one of the affected versions: 7.3(1)d1(1), 7.3(1)n1(1), 8.0(1)(ed), 8.0(1)s2, or 8.3(0)cv(0.833)
  2. Identify the hardware model
    Execute 'show version' and check the 'Hardware' or 'cisco' model identifier in the output
    Affected if The device is a Cisco Nexus 7000 Series, Nexus 7700 Series, or MDS 9000 Series switch
  3. Verify FCoE is configured
    Execute 'show fcoe' or 'show running-config | include fcoe' to check for FCoE-related configuration
    Affected if FCoE is enabled or any FCoE-related interfaces, VLANs, or zones are configured on the device

The device is affected if it runs an NX-OS version within the affected list, belongs to the Nexus 7000/7700 or MDS 9000 families, AND has FCoE configuration present.

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

Upgrade Cisco NX-OS Software to a fixed release (8.3(0)CV(0.944), 8.3(0)ISH(0.62), 8.1(1), or later). If upgrade is not immediately feasible, consider disabling FCoE or implementing network segmentation controls to limit adjacent attacker access.

Fix this in Mds 9000 Nx Os Scoped from the published advisory
  • Consultation4.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
18.0 hours of engineering $3,200
Get help mitigating

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $5,120.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2017-6655 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

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-2017-6655 in production — separate from our analysis above.

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.

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