dbcve.org
Nx OsOperating system · Cisco

CVE-2018-0102

HIGH · 7.4 CVSS v3.0 Published 2018-01-18
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
79/100
Remediation priority · High
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 Pong tool of Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability exists because the affected software attempts to free the same area of memory twice. An attacker could exploit this vulnerability by sending a pong request to an affected device from a location on the network that causes the pong reply packet to egress both a FabricPath port and a non-FabricPath port. An exploit could allow the attacker to cause a dual or quad supervisor virtual port-channel (vPC) to reload. This vulnerability affects the following products when running Cisco NX-OS Software Release 7.2(1)D(1), 7.2(2)D1(1), or 7.2(2)D1(2) with both the Pong and FabricPath features enabled and the FabricPath port is actively monitored via a SPAN session: Cisco Nexus 7000 Series Switches and Cisco Nexus 7700 Series Switches. Cisco Bug IDs: CSCuv98660.

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 double-free vulnerability exists in the Pong tool of Cisco NX-OS on Nexus 7000/7700 series switches. When Pong and FabricPath features are both enabled and a FabricPath port is monitored via SPAN, a pong reply packet egressing both a FabricPath and non-FabricPath port causes memory corruption leading to device reload.

MitigationDisable the Pong feature, disable FabricPath, or remove SPAN monitoring from FabricPath ports if these features are not required, otherwise apply vendor patches when available.

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
Nx OsOperating system
Affected:= 7.2\(1\)d\(1\)= 7.2\(2\)d1\(1\)= 7.2\(2\)d1\(2\)

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
Changed
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.0/AV:A/AC:L/PR:N/UI:N/S:C/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. Confirm NX-OS version
    Run 'show version' on the switch CLI and locate the NX-OS version string in the output
    Affected if The version shown is exactly 7.2(1)d(1), 7.2(2)d1(1), or 7.2(2)d1(2)
  2. Verify Pong feature status
    Run 'show feature | include pong' or 'show feature' and look for the Pong feature in the enabled state
    Affected if The Pong feature appears as enabled in the feature list
  3. Verify FabricPath feature status
    Run 'show feature | include fabricpath' or 'show feature' and look for FabricPath in the enabled state
    Affected if The FabricPath feature appears as enabled in the feature list
  4. Check SPAN monitoring on FabricPath ports
    Run 'show monitor session all' or 'show span' to list all SPAN sessions, then cross-reference with 'show interface' or 'show fabricpath is-id' to identify FabricPath-enabled ports
    Affected if Any SPAN session is configured to monitor a port that is operating in FabricPath mode

A user is affected if their switch runs one of the three listed NX-OS versions AND has both Pong and FabricPath features enabled AND has SPAN monitoring configured on a FabricPath port, creating the conditions for the double-free during pong reply packet egress.

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

Disable the Pong feature, disable FabricPath, or remove SPAN monitoring from FabricPath ports if these features are not required, otherwise apply vendor patches when available.

Fix this in Nx Os Scoped from the published advisory
  • Consultation3.0 h
  • Implementation4.0 h
  • Testing3.0 h
  • Review / QA2.0 h
12.0 hours of engineering $2,130
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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-2018-0102 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
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  • No spam, self-promotion, credentials, or personal data